Dissertations / Theses on the topic 'Australian birds'

The movements of nomadic species are poorly understood, being highly dynamic over time and space. There is an urgent need to better understand this group as current conservation approaches appear not to be providing adequate protection. In this thesis, I evaluate a survey method to monitor this dynamic group, assess environmental variables driving their movements over time, and explore how rainfall structures the overall avian community. To date, no standardized, large-scale monitoring has been carried out for arid zone or nomadic species. In Chapter 2, I describe a protocol for surveying this group over five years using two survey methods. Detection probabilities and robust density estimates were generated for 64 species and showed the majority fluctuated markedly over time. Line transect surveys were more effective for species richness and abundance measures. This survey method provides the first standardized density estimates for this assemblage and can be easily repeated in future for this and other remote, arid biological communities. The movement characteristics of species with unpredictable, aseasonal movements are very poorly understood and difficult to measure. In Chapter 3, I develop a method for quantifying extent of bird movement by analysing changes in species’ site persistence and variability in inter-annual densities over time, and compare results with existing movement classifications. Continuous variation in extent of species movement indicated that a binary grouping of resident versus nomadic species is inappropriate. Existing movement classifications likely underestimate species movements within arid regions of their distribution, suggesting that caution is needed when using sweeping species-level classifications, especially for Australian birds whose movements can be heavily environment-dependent. Unlike regular migration, which is triggered by seasonal cues such as day length and temperature, movement in nomads is thought to be triggered by less predictable environmental conditions. In Chapter 4, I explore the relative influence of dynamic and static environmental variables on species abundance. Dynamic variables were more important for nomadic versus resident species but static variables were equally important for nomadic and resident species. These findings suggest that habitat structure is important to consider in addition to dynamic environmental features for understanding nomadic species movements. Pulse events are thought to be positively correlated with nomadic species movements and to play an important role in structuring arid biological communities. In Chapter 5, I investigate how structural changes observed in Australia’s arid bird community relate to rainfall and vegetation greenness. The importance of rainfall was mediated through vegetation growth and the community is dynamic at a local level but exhibits stability at a landscape level, underscoring the importance of connectivity between suitable habitats within this landscape to enable species to reshuffle among sites. In sum, my thesis highlights the importance of standardized data for enabling an empirical approach to understanding nomadic and arid-zone bird species. Findings will advance our understanding of these species’ dynamics and lay groundwork for improving protection of this group by identifying further research priorities.

Riparian zones are a characteristic component of many landscapes throughout the world and increasingly are valued as key areas for biodiversity conservation. Their importance for bird communities has been well recognised in semi-arid environments and in modified landscapes where there is a marked contrast between riparian and adjacent non-riparian vegetation. The value of riparian zones in largely intact landscapes with continuous vegetation cover is less well understood. This research examined the importance of riparian habitats for avifauna conservation by investigating the ecological interactions contributing to the pattern of bird assemblages in riparian and adjacent non-riparian habitats. Specifically, the focus is on the bird assemblages of riparian zones and those of adjacent non-riparian vegetation types and the influence that associated differences in resource availabilities, habitat structure and conditions have on observed patterns. This study was conducted in the foothill forests of the Victorian Highlands, south-east Australia. Mixed-species eucalypt (genus Eucalyptus) forests dominate the vegetation of this region. Site selection was based on the occurrence of suitable riparian habitat interspersed within extensive, relatively undisturbed (i.e. no recent timber harvesting or fire events) forest mosaics. A series of 30 paired riparian and non-riparian sites were established among six stream systems in three forest areas (Bunyip State Park, Kinglake National Park and Marysville State Forest). Riparian sites were positioned alongside the stream and the non-riparian partner site was positioned on a facing slope at a distance of approximately 750 m. Bird surveys were carried out during 29 visits to each site between July 2001 and December 2002. Riparian sites were floristically distinct from non-riparian sites and had a more complex vegetation structure, including a mid-storey tree layer mostly absent from non-riparian sites, extensive fine litter and coarse woody debris, and dense ground-layer vegetation (e.g. sedges and ground ferns). The characteristic features of non-riparian habitats included a relatively dense canopy cover, a ground layer dominated by grasses and fine litter, and a high density of canopy-forming trees in the smaller size-classes. Riparian zones supported a significantly greater species richness, abundance and diversity of birds when compared to non-riparian habitats. The composition of bird assemblages differed significantly between riparian and non-riparian habitats, with riparian assemblages displaying a higher level of similarity among sites. The strongest contributors to observed dissimilarities between habitat types included species that occurred exclusively in either habitat type or species with large contrasts in abundance between habitat types. Much of the avifauna (36%) of the study area is composed of species that are common and widespread in south-east Australia (i.e. forest generalists). Riparian habitats were characterised by a suite of species more typical of wetter forest types in south-east Australia and many of these species had a restricted distribution in the forest mosaic. Some species (7%) occurred exclusively in riparian habitats (i.e. riparian selective species) while others (43%) were strongly linked to these habitats (i.e. riparian associated species). A smaller proportion of species occurred exclusively (2%) in non-riparian habitats (i.e. non-riparian selective species) or were strongly linked to these habitats (10%; i.e. non-riparian associated species). To examine the seasonal dynamics of assemblages, the variation through time in species richness, abundance and composition was compared between riparian and non-riparian sites. Riparian assemblages supported greater richness and abundance, and displayed less variation in these parameters, than non-riparian assemblages at all times. The species composition of riparian assemblages was distinct from non-riparian assemblages throughout the annual cycle. An influx of seasonal migrants elevated species richness and abundance in the forest landscape during spring and summer. The large-scale movement pattern (e.g. coastal migrant, inland migrant) adopted by migrating species was associated with their preference for riparian or non-riparian habitats in the landscape. Species which migrate north-south along the east coast of mainland Australia (i.e. coastal migrants) used riparian zones disproportionately; eight of eleven species were riparian associated species. Species which migrate north-south through inland Australia (i.e. inland migrants) were mostly associated with non-riparian habitats. The significant differences in the dynamics of community structure between riparian and non-riparian assemblages shows that there is a disproportionate use of riparian zones across the landscape and that they provide higher quality habitat for birds throughout the annual cycle. To examine the ecological mechanisms by which riparian assemblages are richer and support more individual birds, the number of ecological groups (foraging, nest-type and body mass groups) represented, and the species richness of these groups, was compared between riparian and non-riparian assemblages. The structurally complex vegetation and distinctive habitat features (e.g. aquatic environments, damp sheltered litter) provided in the riparian zone, resulted in the consistent addition of ecological groups to riparian assemblages (e.g. sheltered ground – invertebrates foraging group) compared with non-riparian assemblages. Greater species richness was accommodated in most foraging, nest-type and body mass groups in riparian than non-riparian assemblages. Riparian zones facilitated greater richness within ecological groups by providing conditions (i.e. more types of resources and greater abundance of resources) that promoted ecological segregation between ecologically similar species. For a set of commonly observed species, significant differences in their use of structural features, substrates and heights were registered between riparian and non-riparian habitats. The availability and dynamics of resources in riparian and non-riparian habitats were examined to determine if there is differential availability of particular resources, or in their temporal availability, throughout the annual cycle. Riparian zones supported more abundant and temporally reliable eucalypt flowering (i.e. nectar) than non-riparian habitats throughout the annual cycle. Riparian zones also supported an extensive loose bark resource (an important microhabitat for invertebrates) including more peeling bark and hanging bark throughout the year than at non-riparian sites. The productivity of eucalypts differed between habitat types, being higher in riparian zones at most times for all eucalypts combined, and for some species (e.g. Narrow-leaved Peppermint Eucalyptus radiata). Non-riparian habitats provided an abundant nectar resource (i.e. shrub flowering) at particular periods in the annual cycle. Birds showed clear relationships with the availability of specific food (i.e. nectar) and foraging resources (i.e. loose bark). The demonstration of a greater abundance of resources and higher primary productivity in riparian zones is consistent with the hypothesis that these linear strips that occupy only a small proportion of the landscape have a disproportionately high value for birds. Riparian zones in continuous eucalypt forest provide high quality habitats that contribute to the diversity of habitats and resources available to birds in the forest mosaic, with positive benefits for the landscape-level species pool. Despite riparian and non-riparian habitat supporting distinct assemblages of birds, strong linkages are maintained along the riparian-upslope gradient. Clearly, the maintenance of diverse and sustainable assemblages of birds in forest landscapes depends on complementary management of both riparian and non-riparian vegetation.

The urbanised environment provides ecologists with unique situations in which to undertake ecological study. It has been said that urbanisation is like a natural experiment; we often have populations of animals that have gone from living in natural or semi-natural environments to living in a highly modified anthropogenic environment. These situations provide ideal settings to study the ecological and behavioural differences that may develop in populations located in different habitats. Urbanisation typically results in a minority of species dominating the fauna, and this thesis aimed to examine one such species, the Australian magpie. Despite the magpie being a common and well-liked suburban bird, the majority of previous research on this species has been undertaken within rural or exurban locations. This thesis aimed to examine what actually happens to the species when it lives in the suburban environment. In particular I focused on specific behavioural and ecological features, to see if there were any particular adaptations the suburban magpies showed and also if the suburban habitats provide certain resources favourable to the magpies and what ecological effects these may have. Comparisons of the territory structure and resources of rural and suburban magpies showed that although many features of the territory are similar between rural and suburban locations, notably the choice of native nest trees, magpie territories within suburban areas were smaller and contained more anthropogenic features. The reduced territory size may possibly be related to a greater abundance of key food resources also evident within suburban areas. Furthermore, suburban magpies are more successful in their foraging attempts, again possibly reflecting a more abundant food supply in suburbia and also the simplified nature of suburban foraging areas might facilitate more successful foraging. The increased foraging success is likely to explain the greater provisioning rate to nestling suburban magpies. Suburban magpies also utilised human provided foods. I quantified the extent of wildlife feeding within many of the suburban study sites of this thesis (through the use of questionnaire surveys). In each of the locations it was evident that at least one person (usually more) was providing a regular supply of food to wildlife and magpies appeared to be the main recipients of this food. Previous ecological studies suggest the provision of extra food to avian populations is likely to affect the breeding ecology, and this was so for magpies. The suburban populations initiated breeding significantly earlier than rural magpies. To test the influence of food, supplementary food was provided to rural magpies, not currently receiving any additional human provided foods. The fed rural magpies initiated breeding before control rural magpies (i.e. not receiving any additional food) but suburban magpies still initiated breeding before all other groups. This suggests additional factors present within suburbia, such as warmer temperatures, may also control the timing of breeding in magpies. Magpies in rural and suburban locations lived within different vertebrate communities. Within suburban magpie territories a greater number of intrusions were made by domestic animals, notably dogs (Canis lupus) and cats (Felis domesticus). The frequency of raptors entering the territorial areas occupied by magpies appears to suggest such events are more common in rural areas. The number of humans entering magpie territories was obviously greater in the more populated suburban areas and the majority of magpies responded neutrally to humans. However a group of magpies that previously exhibited extreme aggression towards humans were found to have a greater frequency of aggressive interactions with potential predatory intruders, which were primarily humans. Subsequent examination of the level of corticosterone from this aggressive group of magpies found that a high level of aggressive interactions with potential predators and humans is reflected in higher level of corticosterone, which may have implications for further behavioural and even physiological changes. An ability to habituate to human in urbanised areas is a key attribute of successful synanthropic species. Comparisons of magpies disturbance distances at different points along the urban gradient (the gradient that runs from the urbaised city to natural wildlands) found suburban magpies only responded to humans when they had approached to a close distance (often less than one metre) and many simply walked away to avoid the approaching human. Rural and exurban magpies responded to humans at greater distances than suburban magpies. The distance at which they responded to the human was usually 100 meters plus, and these magpies always flew away. A continuation of this investigation over a temporal scale again found the large difference in response to humans, with suburban magpies exhibiting a decreased response towards humans. However, a certain proportion of responses from suburban magpies were also aggressive. The examination of disturbance distance over the breeding season found that in suburban magpies the responses of most disturbance distance variables remained similar between breeding stages. Rural magpies, however, exhibited variation in their responses towards humans depending on the stage of breeding. It is suggested that the response of rural magpies may be a typical fear response towards an unusual potential threat. The studies presented in this thesis show that magpies have the behavioural capacity to take advantage of resources in suburban landscapes that are not available or are in lessor supply in rural landscapes, it is these abilities that facilitate the magpies synanthropy.

Despite increasing publicity, habitat loss and fragmentation remain a serious threat to biodiversity. The main objectives of this research were (i) to study the effects of forest fragmentation on the distribution and abundance of resident birds in the fragmented littoral forests of southeastern Madagascar and temperate woodlands of southeastern Australia at three spatial scales (patch, landscape and regional) and (ii) to place the results of these case studies within the realms of the equilibrium theory of island biogeography and its descendent theories, to ascertain whether it is appropriate to use these theories to derive conservation scenarios within these threatened regions. Deforestation of Madagascar's remaining forests is considered a global concern due to both its current high intensity and the small amount of forest claimed to be remaining on the island. Surprisingly, very few studies have considered the impacts of forest fragmentation on bird diversity in Madagascar. A multi-scale study on the effects of littoral forest fragmentation and degradation on birds is therefore a major step forward for bird conservation on the island. Furthermore, prior to this study no known work has been conducted on the avifauna within the threatened littoral forests of eastern Madagascar. My results indicated that (i) the littoral forests contained bird species assemblages that were unique when compared to neighbouring forest habitats, (ii) many forest-dependent bird species were significantly affected by habitat structure and especially proximity to forest edge and (iii) many forest-dependent species were affected by landscape factors such as remnant shape and remnant size. No relationship was found between measures of landscape composition, remnant 'isolation' and bird distribution within littoral forest remnants.

Thesis (MSc)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: Human-modified habitats form increasingly large components of landscapes, threatening biodiversity and creating challenges for conservation. In some cases altered habitats form entirely novel ecosystems that may support new combinations of species and species abundances, and create habitat space in otherwise transformed landscapes. In the Western Cape of South Africa, woody invasive species contribute to landscape-level habitat transformation and form novel ecosystems. Invasive Australian Acacia species are especially problematic in lowland areas where they create dense thickets and substantially transform both biotic communities and abiotic processes. Despite the prominence of Acacia thickets across the Western Cape, their ability to support native fauna is not well understood and the objective of this study was to assess the significance of Acacia thickets as habitat for the region’s avifauna. Birds were surveyed in Acacia thickets in the south-western Western Cape in three seasons to examine species richness, abundance and functional abundance. Furthermore, I examined the extent to which differences in patch-level vegetation structure alter bird communities. Between survey sites and seasons, significant variation was observed in assemblage richness, density, median body size and biomass. Variation in vegetation density, stem density, mean vegetation height and total canopy cover best explained variation in bird assemblages. Eighty species were estimated to utilize Acacia thickets and assemblages had a mean density of 7.78 birds per ha. The most abundant feeding guilds were the mixed feeders and insectivores. The median body size observed was 15.2 g and the body size frequency distribution of all species in Acacia spanned a similar range compared to the body size frequency distribution for the species list for the entire Western Cape. The mean biomass of bird communities was 0.224 kg per ha. Using data on bird density and biomass, Acacia thickets across the Fynbos Biome support and estimated average of over 21 million birds with a combined biomass of over 600 thousand kg. This study found that Acacia thickets in the Western Cape support a subset of the region’s birds with the most abundant species being small mixed feeders, which are also frequently urban-adapted. Compared with other habitat types, Acacia support bird assemblages with moderate species richness and density. This study shows that Acacia thickets, as a novel habitat, provide a significant amount of habitat space in a highly transformed landscape and highlights the need for comprehensive evaluation of altered habitats before assumptions are made about their ecological value.
AFRIKAANSE OPSOMMING: Getransformeerde habitatte maak vermeerderend groot deel uit van die omgewing, dit bedreig biodiversiteit en skep groter uitdagings vir bewaring. In sommige gevalle vorm hierdie getransformeerde habitatte geheel nuwe ekosisteme wat moontlik nuwe kombinasies van spesies en spesie volopheid kan onderhou. Verder skep nuwe ekosisteme habitat spasie in anders veranderde landskappe. In die Wes-Kaap van Suid-Afrika dra die Australiese Acacia indringer spesies is veral problematies in laagliggende areas, aangesien dit digte ruigtes vorm, asook beide die biotiese gemeenskappe en die abiotiese prosesse aansienlik transformeer. Ten spyte daarvan dat daar volop Acacia ruigtes in die WesKaap is, word min verstaan van hul vermoë om inheemse fauna te onderhou. Die hoofdoel van hierdie studie was om die belang van Acacia ruigtes as habitat vir die area se voëllewe te bepaal. Voël-opnames in die suidwestelike dele van die Wes-Kaap is gedoen in Acacia ruigtes oor drie seisoene, om spesierykheid, volopheid en funksionele volopheid te ondersoek. Verder is die mate waartoe verskille in die plotte van die plantegroei struktuur, die voëlgemeenskappe verander, geondersoek. Daar was aansienlike variasie waargeneem in die spesiesamestelling rykheid, voorkoms digtheid, mediaan liggaamsgrootte en biomassa van die voëls tussen die onderskeie voëlopnaam plotte en die seisoene. Die variasie in plantegroei digtheid, stam digtheid, mediaan plantegroeihoogte en totale kroonbedekking verduidelik hierdie variasie in spesiesamestelling die beste. Tagtig voëlspesies Acacia ruigtes benut en die populasiesamestelling het ‘n gemiddelde digtheid van 7,78 voëls per ha. Die mees algemene voel-voeding-guldes was die gemengde-voedsel-vreters en insekvreters. Die median liggaamsgrootte waargeneem was 15,2 g en die liggaamsgrootte frekwensieverspreiding van alle spesies in Acacia ruigtes is ooreenkomstig met die liggaamsgrootte frekwensieverspreiding vir die spesielys vir die hele Wes-Kaap. Die gemiddelde biomassa van voel gemeenskappe was 0.224 kg per ha. Acacia ruigtes oor die fynbosbioom wat ‘n geskatte gemiddelde van meer as 21 miljoen voels ondersteun, met ‘n gesamentlike biomassa van meer as 600 duisend kg. Hierdie studie het bevind dat Acacia ruigtes in die Wes-Kaap ‘n onderafdeling van die streek se voels ondersteun, met die mees algemene spesies as die klein gemengde-voedsel-vreters, wat ook dikwels stedelik aangepas is. In vergelyking met ander habitattipes ondersteun Acacia ruigtes voel samestellings met matige spesierykheid en digtheid. Hierdie studie toon dat die Acacia ruigtes, as ‘n nuwe habitat, ‘n beduidende hoeveelheid habitat ruimte in ‘n hoogs getransformeerde omgewing skep en beklemtoon die behoefte aan ‘n omvattende evaluering van veranderde habitatte, voor aannames gemaak word oor hul ekologiese waarde.

The White-bellied Sea-Eagle Haliaeetus leucogaster is widespread in Australia, but has been the subject of conservation concern due to suggested localised declines and extinctions. Regionalised monitoring programmes have addressed some aspects of local concern, however a broader approach is needed to gain an understanding of large-scale processes affecting long-term persistence at scales equivalent to the species Australian range. Ultimately, the ability to predict change in population size over time accurately depends on the scale of analysis. By necessity, ecological studies using direct sampling techniques are often made across spatial scales smaller than a species geographic range and across relatively short time frames. This seems counter-intuitive considering that long-term species persistence is often dependent on large-scale processes. The principal aim of this thesis was to identify historical and contemporary forces responsible for the current pattern of population structure in H. leucogaster. This required a multi-scale approach, and the resulting research uses genetic, distributional and morphometric data. Haliaeetus leucogaster is a large territorial raptor that historically has been associated with coastal regions, lakes and perennial river systems. It has an extensive worldwide distribution from the western coast of India throughout the Indomalaysian region, Papua New Guinea and Australia. By virtue of the species' large-scale distribution, in Australia it is fairly cosmopolitan in its use of habitat and prey types. Haliaeetus leucogaster is monomorphic for adult plumage colouration, but in body size displays reversed sexual dimorphism with female birds significantly larger. A discriminant function based on 10 morphometric characters was 100% effective in discriminating between 19 males and 18 females that had been sexed using molecular genetic methods. Re-classification using a jackknife procedure correctly identified 92% of individuals. The discriminant function should be a viable alternative to genetic sexing or laparoscopy for a large proportion of individuals within the Australo-Papuan range of this species; and can also be used to identify a small proportion of "ambiguous" individuals for which reliable sexing will require those other techniques. I used mitochondrial (mtDNA) control region sequence data to investigate the current distribution of genetic variation in this species at the continental level and within and between specified regional units. I was specifically interested in identifying breaks in genetic connectivity between the west and east of the continent and between Tasmania and the Australian mainland. Overall, genetic diversity was low and there was no significant level of genetic subdivision between regions. The observed genetic distribution suggests that the population expanded from a bottleneck approximately 160 000 years ago during the late Pleistocene, and spread throughout the continent through a contiguous range expansion. There is insufficient evidence to suggest division of the population into different units for conservation management purposes based on the theoretical definition of the 'evolutionary significant unit'. It is clear from the analysis that there are signatures of both historical and contemporary processes affecting the current distribution. Given the suggestion that population expansion has been relatively recent, additional sampling and confirmation of the perceived pattern of population structure using a nuclear marker is recommended to validate conservation monitoring and management at a continental scale. To determine the existence of perceived population declines across ecological time scales, I analysed the Australian Bird Atlas Data to identify the extent and pattern of change in range and density of the species between three Atlas Periods (1901-1976, 1977-1981 and 1998-2001) using a new standardised frequency measure, the Occupancy Index (OI) for 1° blocks (approx. 100km2) across the continent. At the continental scale, there was no significant difference in the spatial extent of occupancy between Atlas Periods. However, there were considerable changes in frequency and range extent between defined regions, and there were distinct differences in the pattern of change in OI between coastal and inland blocks over time. Coastal blocks showed much more change than inland blocks, with a clear increase in the use of coastal blocks, accompanied by a decrease in inland blocks, during the 1977-1981 Atlas Period, relative to both other Atlas Periods. The over-riding factor associated with distributional shifts and frequency changes was apparently climatic fluctuation (the 1977-1981 period showing the influence of El Nino associated drought). The impression of abundance was strongly dependent on both the temporal and spatial scale of analysis. To test for correspondence between geographic variation in morphology and geographic variation in mtDNA I analysed morphometric data from 95 individuals from Australia and Papua New Guinea. First, the degree of morphometric variation between specified regions was determined. This was then compared with the pattern of genetic differentiation. There was a strong latitudinal cline in body dimensions. However, there was no relationship between morphometric variation and patterns of genetic variation at least for mtDNA. Females showed a pattern of isolation by distance based on morphometric characters whereas males did not. Three hypotheses to explain the pattern of morphometric variation were considered: phenotypic plasticity, natural selection and secondary contact between previously isolated populations. I conclude that the pattern of morphometric variation is best explained by the suggestion that there is sufficient local recruitment for natural selection to maintain the observed pattern of morphometric variation. This implies that gene flow may not be as widespread as the mtDNA analysis suggested. In this instance either the relatively recent colonisation history of the species or the inability of the mtDNA marker to detect high mutation rates among traits responsible for maintaining morphometric variation may be overestimating the levels of mixing among regions. As might be expected given the physical scale over which this study was conducted, the pattern of genetic, morphometric and physical distribution varied dependent on the scale of analysis. Regional patterns of genetic variation, trends in occupancy and density and morphometric variation did not reflect continental patterns, reinforcing the contention that extrapolation of data from local or regional levels is often inappropriate. The combined indirect methodologies applied in this study circumvent the restrictions imposed by direct ecological sampling, because they allow survey across large geographic and temporal scales effectively covering the entire Australian range of H. leucogaster. They also allow exploration of the evolutionary factors underpinning the species' current distribution.

Information about tropical seabird communities is less abundant in the literature than for those that occur at higher latitudes. In research papers examining seabird breeding communities in tropical environments, it has been found that food availability was temporally and spatially variable in comparison to higher latitudes. This environmental variability would be expected to influence the life-history traits of tropical seabird species, and in turn, the structure of the communities in which they occur. To examine the impact of environmental variability upon the life-history traits and community structure of tropical seabirds, a comparative study of the breeding strategies of three tropical tern species and an outlier, shearwater species was carried out, at the Lowendal Islands, Western Australia (20o39’52S; 115o34’44E) between 1996 and 2000. Bridled Terns Sterna anaethetus and Wedge-tailed Shearwaters Puffinus pacificus shared the life-history traits of migration or dispersal from the breeding colony and east-Indian Ocean metapopulation when not breeding, a summer breeding schedule, nest-site fidelity, concealed nest-sites, clutch size of one, offshore and pelagic foraging regime, and protracted post-natal growth. Crested Terns Sterna bergii and Lesser Crested Terns Stern bengalenis bred within the same colony and shared the life-history traits of presence at the breeding colony when not breeding, an autumn breeding schedule, change in colony site each season, open dense nest-sites, brood size of one. inshore foraging regime (as well as offshore for Crested Terns) and rapid post-natal growth. It was found that each species experienced variation in nest-site occupancy and/or colony size, as well as variation in timing of breeding and breeding success between years. The effects upon each species seemed to operate independently, as concurrently breeding species did not appear affected by the same events, with the exception of cyclones. Late and/or poor breeding success in a species often coincided with oceanographic changes in the north-west region, such as fluctuations in the strength of flow and temperature of the Leewin Current. The Leewin Current is a warm water, low salinity current flowing southwards along most of the Western Australian coastline and has a stronger, warmer flow during El Nino Southern Oscillation (ENSO) events. Cyclone activity is also influenced by ENSO induced changes in the region’s water temperature. Changes in the Leewin Current affected the timing of breeding for Wedge-tailed Shearwaters, and feeding conditions for all study species, presumably as a result of changes in prey availability, while cyclone events delayed breeding for Crested Terns and Lesser Shearwaters in the years studied. Cyclone events were the most obvious cause of re-laying in the case of Crested Terns and Lesser Crested Terns, and breeding failure in the case of Bridled Terns and Wedge-tailed Shearwaters. Breeding failure was common among later breeders in the Crested Tern colonies. Breeding success was relatively high for lesser Crested Terns in all years studied, as they hatched and fledged their chicks within the Crested Tern colony among the first wave of breeders. There was some overlap in the diets and foraging grounds of the four study species. Crested terns and Lesser Crested Terns had the most similar diet, however, Crested Terns appeared to be the most opportunistic foragers, with the highest diversity of dietary prey, while Lesser Crested Terns diet consisted of a high proportion of atherinids. Bridled Terns has the next highest prey diversity, while half the diet of Wedge-tailed Shearwaters in this region, similar to conspecifics elsewhere, consisted of squid. Wedge-tailed Shearwaters were observed to be offshore and pelagic foragers. Their distribution in the waters surrounding the Lowendal Islands ranged to the full extent of observation transects(63 Km), and most likely beyond, excluding inshore waters (i.e. within 5 km of islands). They were not present in the vicinity of the Lowendal Islands when they were not breeding. Bridled Terns were observed to be offshore foragers, also ranging to the full extent of transects, and most likely beyond, occasionally including inshore waters. They were rarely observed when not breeding, with the exception of a small number of fledglings at the end of the breeding season. Crested Terns were observed to combine inshore and offshore foraging grounds, only ranging to the full extent of transects during their breeding season. Lesser Crested Terns were observed foraging inshore only. Chick provisioning, in terms of meal size and frequency, varied between years and within seasons for all species. It was demonstrated that there were differences in mean corrected meal sizes between years for Wedge-tailed Shearwaters, and the same was inferred from chick growth curves for Bridled Terns. Wedge-tailed Shearwaters provisioned their chicks with larger meal sizes and a higher occurrence of double feeds in 1996/97 than in other years studied. The amount of time spent feeding chicks in the burrow by Wedge-tailed Shearwaters adults became shorter as the breeding season progressed. It was demonstrated that all three tern species increased the meal size delivered to chicks as they grew. Wedge-tailed Shearwaters did not increase meal size as the season progressed, however they did increase feeding frequency. The feeding frequency of Crested Terns was highest in 1999, nearly doubling that observed in 1997 and 1998. In 1998 Lesser Crested Terns fed their chicks up to six times more frequently than Crested Terns. Chick growth varied for Wedge-tailed Shearwaters and Bridled Terns between seasons. Bridled Tern chicks grew more rapidly in 1997/98, were heavier and reached higher asymptotes for all linear parameters, the exception of wing length, than in 2000. On the other hand, Wedge-tailed Shearwater chicks grew more rapidly in 1999/2000 than in 1997/98, however, they attained similar asymototes for all parameters in both years. In the absence of repeat measures of same individuals, Crested Tern and Lesser Crested tern growth was examined using age categorization based on wing and tail feather development. Both species appeared to attain similar sizes at similar rates in each year. Wedge-tailed Shearwaters accumulated weight up to 30% in excess of mean adult weight in all seasons. This is a common trait exhibited in procellarigorms, and some weight loss occurs prior to fledging. It is suggested, based upon evidence from other studies in which weight loss prior to fledging was found to be water loss, that lipid accumulation acts as an insurance for the period after fledging when young are leaning to forage for themselves. The information gathered for this project found no direct evidence of competition among the species comprising the seabird community if Lowendal Islands. Niche overlap occurred amongst all species, particularly in the case of lesser Crested Terns and Crested Terns, which shared breeding phenology, breeding colonies, foraging grounds and dietary overlap. Niche overlap also occurred between Wedge-tailed Shearwaters and Bridled Terns, which shared breeding phenology and foraging grounds.

Includes bibliographical references (leaves 150-161). Documents the historical distribution and subsequent decline of bush stone-curlews in South Australia, determines their current distribution and status on Kangaroo Island, their home range sizes and movements, the characteristics of foraging habitat, day roost areas and nest sites and the availability of habitat, the diet and food resources, and potential threats to the population. As a result of the findings of this survey, bush stone-curlews have been downgraded from endangered to vulnerable in South Australia.

Brian Castro, écrivain australien contemporain d’origine chinoise, auteur de dix romans, a été souvent appréhendé par la critique littéraire par le seul biais de ses origines. La lecture de son oeuvre, pourtant, révèle une esthétique et une puissance poétique qui dépassent largement cette catégorie réductrice.Afin d’établir les contours de cette esthétique, le présent travail s’est intéressé à quatre romans qui synthétisent un travail d’écriture de trente années : Birds of Passage (1989), After China (1992), The Garden Book (2005) et The Bath Fugues (2009). Nous brossons tout d’abord un historique de la littérature australienne et des enjeux sociétaux et culturels qui la sous-tendent pour déterminer quelles stratégies l’auteur met en oeuvre pour affirmer une identité littéraire singulière, ni totalement nationale, multiculturelle, ou (post)moderne.Cette singularité posée, nous avons recours à des outils d’analyse empruntant à divers courants de critique littéraire pour dégager les lignes de force esthétiques de l’oeuvre de Castro. La forme musicale de la fugue est en ce sens une clé d’entrée essentielle en ce qu’elle structure autant qu’elle inspire l’écriture de l’auteur, tant au niveau de la caractérisation, du récit ou encore de la diégèse, donnant ainsi naissance à une prose dont la force créatrice n’a rien à envier à la poésie. Pour le lecteur, le résultat en est une expérience de déstabilisation qui vise à l’amener à se questionner sur la perméabilité et la futilité des préjugés et catégories, qu’ils soient sociétaux, culturels ou littéraires
Australian writer Brian Castro is the author of ten novels, among which Birds of Passage (1989), After China (1992), The Garden Book (2005) and The Bath Fugues (2009) – the four works at the core of the present study. Owing to his Chinese origins and his elaborate style, literary criticism in Australia has labelled him an ethnic writer whose novels are deemed overly – and overtly – complex and opaque.Our thesis aims at establishing why Castro’s works, precisely because of their sophistication, deserve an alternate approach. We start with a historical survey of Australia’s “national” and “multicultural” literature. This will bring to light how Castro, being well aware of his nation’s love for social, cultural and literary categorizations, strives to break free from them.This desire permeates the whole of his literary endeavour, and our analysis borrows from several traditions of literary criticism to determine the characteristics of Castro’s unique aesthetics. To achieve this, the musical form of the fugue is a particularly powerful analytic tool, in that this musical genre allows us to better understand the elaborate mechanisms at work in the way the author approaches, among others, characterization, plot and diegesis.Far from the easy reads that Australia’s literature market promotes, Brian Castro’s unique works of fiction are an invitation to embrace destabilization in order to examine a prose whose poetic force will help the reader liberate themselves from established racial, cultural and literary categories

Agricultural environments are critical to the conservation of biota throughout the world. This is due both to the limited extent of current reserve systems and the large, and still expanding, proportion of terrestrial environments already dominated by agricultural land-uses. Consequently, there is a growing call from scientists around the world for the need to maximise the conservation value of agricultural environments. Efforts to identify key influences on the conservation status of fauna in agricultural landscapes have taken complementary approaches. Many studies have focussed on the role of remnant or semi-natural vegetation, and emphasised the influence on biota of spatial patterns in the landscape. Others have recognised that many species use diverse ‘countryside’ elements (matrix habitats) within farmland, and emphasise the benefits of landscape heterogeneity for conservation. Here, these research themes have been combined. This study takes a whole-of-landscape approach to investigating how landscape pattern and countryside heterogeneity influence the occurrence of birds in agricultural environments. Birds were sampled in 27 agricultural mosaics, each 1 km x 1 km in size (100 ha), in Gippsland, south-eastern Australia. Mosaics were selected to incorporate variation in two landscape properties: the cover of native vegetation, and richness of different types of element (i.e. land-uses/vegetation types). In each mosaic, 15 fixed sampling locations were stratified among seven different elements in proportion to their cover in the mosaic: native vegetation, linear vegetation, tree plantation, scattered paddock trees, pasture, wetlands and farm dams. Six point counts of birds were undertaken at all sample points in each mosaic: three each in the breeding and non-breeding months of a one-year period (October 2004 – August 2005). Independent measures of the composition, configuration, and heterogeneity of elements in the mosaic had differing effects on the richness of bird species recorded in these same mosaics. Sub-groups of birds based on habitat requirements responded most strongly to the extent of preferred element types in mosaics. Woodland birds (those of greatest conservation concern in farmland environments in Australia) were richer in mosaics with higher cover of native vegetation while open-tolerant species responded to the extent of scattered trees. In contrast, for total species richness, mosaic heterogeneity (richness of element types) and landscape context (cover of native vegetation in surrounding area) had the greatest influence. Mosaic structural properties also influenced the composition of entire bird assemblages in study mosaics. Avifaunal composition showed systematic variation along two main gradients which were readily interpreted in relation to landscape properties: 1) a gradient in the cover of wooded vegetation and, 2) the proportional composition of vegetation types in the mosaic. These gradients represent common trajectories of landscape modification associated with agricultural development: namely, the removal of wooded vegetation and the replacement of native species with exotic vegetation (e.g. crops and plantations). Species possessing different characteristics in relation to three avian life-history traits (nest type, feeding guild and clutch size) varied significantly in their position along these gradients of landscape modification. Species with different nesting requirements showed a strong relationship with the gradient in wooded vegetation cover while species belonging to different feeding guilds were influenced by the gradient defined by the replacement of native vegetation with exotic species. More bird species were recorded in native vegetation than in any other type of element sampled in this study. Nevertheless, most countryside elements had value for many species; particularly structurally complex elements such as scattered trees and tree plantation. Further, each type of landscape element contained different bird assemblages. Species that were recorded in a greater number of different types of landscape element were also recorded in more mosaics. This was true for all species and for woodland birds, and indicates that species that can use a greater range of countryside elements may have an increased tolerance of future landscape modification. The richness of woodland species at survey sites in different elements was influenced by features of the mosaic in which they occurred. Notably, the richness of woodland bird species recorded at sites in scattered trees and pasture increased with a greater cover of native vegetation in the overall mosaic. Of the overall pool of woodland bird species documented in the broader study region, 35% of species were not recorded in the agricultural mosaics sampled here. While many of these species were uncommon in the study area, or were associated with vegetation communities infrequently sampled in mosaics, this shows that conservation efforts in agricultural landscapes will not be appropriate for all species. For those woodland species that were recorded, measures of the extent of wooded vegetation cover had a strong, positive influence on the frequency of occurrence of individual species in mosaics. Thus, individual species of woodland bird occurred more frequently in mosaics with a greater cover of wooded vegetation. Nine woodland species showed a stronger response to measures of vegetation cover that included tree plantation and/or scattered trees than to the cover of native vegetation alone. For these species, structurally complex countryside elements provide valuable supplementary habitat at the landscape scale. Results of this study show that landscape properties influence the occurrence of birds in agricultural mosaics. The extent of cover of element types, particularly native vegetation, had the strongest influence on all measures of bird occurrence in mosaics. Thus, native vegetation is vital for the persistence of birds in farmland landscapes and is the primary element on which conservation efforts in these environments depend. Nevertheless, with careful management, countryside elements may provide additional conservation benefits for many bird species. Countryside elements made an important contribution to landscape heterogeneity, the landscape property with greatest influence on overall bird richness in mosaics. Countryside elements also increased the structural complexity of cleared agricultural land, and so have the capacity to enhance connectivity in fragmented landscapes. A focus on these factors (landscape heterogeneity and structural complexity) will provide the greatest opportunities for using countryside elements to increase the conservation value of farmland environments for native fauna. The relatively small scale of this study indicates that the cumulative effect of even small elements in farm mosaics contributes to the structural properties of entire landscapes. Critically, this emphasises the important contribution that individual landholders can make to nature conservation in agricultural environments.

The White-browed Treecreeper Climacteris affinis is one of many woodland-dependent birds that are at risk from the encroachment of human-dominated land-uses into natural landscapes. The White-browed Treecreeper inhabits semi-arid woodlands in north-west Victoria, Australia, a vegetation community that has undergone extreme modification in the last century due to the expansion of agriculture in the region. Extant woodlands represent only 10% of the original woodland cover in the region, and are highly fragmented and disturbed in many districts. Thus, the survival of the White-browed Treecreeper may depend on active management. However, current knowledge of the ecology and biology of this species is virtually non-existent, and inadequate for informed and effective conservation actions. The aim of this thesis is to redress this situation and provide the ecological basis for sound conservation management of the species. The thesis consists of two parts: an investigation of habitat use at three spatial scales and a study of the social organization, nesting requirements, breeding behaviour and reproductive success of a population of White-browed Treecreepers. Fifty-six patches of remnant woodland in north-west Victoria were surveyed to determine the factors affecting the occurrence of the White-browed Treecreeper at the regional scale. It was detected in 16 patches, and was largely confined to two core districts - Yarrara and, Wyperfeld (Pine Plains). The floristic composition of the dominant tree species was an important determinant of patch occupancy, with the results providing quantitative support for the previously suspected affinity for Belah Casuarina pauper and Slender Cypress-pine Callitris gracilis — Buloke Allocasuarina luehmannii woodlands. However, the absence of the White-browed Treecreeper from several districts was due to factors other than a lack of appropriate habitat. Demographic isolation - the distance from the focal patch to the nearest population of the White-browed Treecreeper - was the most important variable in explaining variation in patch occupancy. Patches isolated from other treecreeper populations by more than 8.3 km in landscapes of non-preferred native vegetation, and 3 km in agricultural landscapes, were unlikely to support the White-browed Treecreeper. The impact of habitat loss and fragmentation on the capacity of individuals to move through the landscape (i.e. functional connectivity) is considered in relation to disruption to dispersal and migration, and the potential collapse of local metapopulations. Habitat use was then examined in a network of patches and linear strips of Belah woodland embedded in a predominantly cultivated landscape. A minimum area of 18.5 ha of Belah woodland was identified as the most important criterion for patch occupancy at the local scale. This landscape appeared to be permeable to movement by the White-browed Treecreeper, facilitated by the extensive network of linear habitat, and clusters of small to medium fragments. The third scale of habitat use investigated the frequency of use of 1-ha plots within tracts of occupied woodland. It is important to discriminate between habitat traits that operate at the population level, and those that act as proximate cues for habitat selection by individuals. Woodlands that have high tree density, extensive cover of low-stature shrubs, abundant lichen, a complex vertical structure, and relatively low cover of grass and herbs are likely to support larger populations of the White-browed Treecreeper. However, individuals appeared to be using tree dominance (positive) and tall shrub cover (negative) as proximate environmental stimuli for habitat selectivity. A relatively high cover of ground lichen, which probably reflects a ground layer with low disturbance and high structural complexity, was also a reliable indicator of habitat use. Predictive models were developed which could be used to plan vegetation management to enhance habitat for the White-browed Treecreeper. The results of the regional, landscape and patch-scale investigations emphasise that factors operating at multiple spatial scales influence the suitability of remnant vegetation as habitat for the White-browed Treecreeper. The White-browed Treecreeper is typical of many small Australian passerines in that it has high annual survival, small clutches, a long breeding season, multiple broods and relatively low reproductive rates. Reproductive effort is adjusted through the number of clutches laid rather than clutch size. They occupy relatively large, all-purpose territories throughout the year. However, unlike many group territorial birds, territory size was not related to the number of occupants. The White-browed Treecreeper nests in tree hollows. They select hollows with a southerly orientation where possible, and prefer hollows that were higher from the ground. At Yarrara, there was considerable spatial variation in hollow abundance that, in concert with territorial constraints, restricted the actual availability of hollows to less than the absolute abundance of hollows. Thus, the availability of suitable hollows may limit reproductive productivity in some territories, although the magnitude of this constraint on overall population growth is predicted to be small. However, lack of recruitment of hollow-bearing trees would increase the potential for hollow availability to limit population growth. This prospect is particularly relevant in grazed remnants and those outside the reserve system. Facultative cooperative breeding was confirmed, with groups formed through male philopatry. Consequently, natal dispersal is female-biased, although there was no skew in the sex ratio of the fledglings or the general adult population. Helpers were observed performing all activities associated with parenting except copulation and brooding. Cooperatively breeding groups enjoyed higher fledgling productivity than simple pairs, after statistically accounting for territory and parental quality. However, the difference reflected increased productivity in the 1999-breeding season only, when climatic conditions were more favourable than in 1998. Breeding commenced earlier in 1999, and all breeding units were more likely to attempt a second brood. However, only breeders with helpers were successful in fledging second brood young, and it was this difference that accounted for the overall discrepancy in productivity. The key mechanism for increased success in cooperative groups was a reduction hi the interval between first and second broods, facilitated by compensatory reductions in the level of care to the first brood. Thus, females with helpers probably achieved significant energetic savings during this period, which enabled them to re-lay sooner. Furthermore, they were able to recommence nesting when the fledglings from the first brood were younger because there were more adults to feed the dependent juveniles. The current utility, and possible evolutionary pathways, of cooperative breeding is examined from the perspective of both breeders and helpers. Breeders benefit through enhanced fledgling productivity in good breeding conditions and a reduction in the burden of parental care, which may impart significant energetic savings. Further, breeders may facilitate philopatry as a means for ensuring a minimum level of reproductive success. Helpers benefit through an increase in their inclusive fitness in the absence of opportunities for independent breeding (i.e. ecological constraints) and access to breeding vacancies in the natal or adjacent territories (i.e. benefits of philopatry). However, the majority of breeding unit-years comprised unassisted breeders, which suggests that pairs are selectively favoured under certain environmental or demographic conditions.

Genetic immunization, also known as DNA or polynucleotide immunisation, is well documented to induce broad-based immunity in various animal models of infectious and non-infectious diseases. However, the low potency of DNA vaccines has to date precluded the development of commercial vaccines. The aim of this study was to systematically investigate a number of parameters to improve the potency of DNA vaccines for use in chickens, using a low pathogenic avian influenza (LPAI) virus as a proof-of-concept for their ability to produce a humoral immune response. The index virus used in the study was avian influenza virus A/coot/WA/2727/79 (H6N2), isolated from an apparently healthy Eurasian coot in 1979. Prior to any DNA experiments the virus was rigorously characterized. The virus strain was shown to be an H6 subtype by haemaglutination inhibition (HI) testing and as an N2 subtype by gene sequence analysis. The isolate was shown to be able to grow on MDCK cells in the absence of exogenous trypsin. It was further biologically characterized as LPAI with an intravenous pathogenicity index (IVPI) of 0.15 and a motif of 321PQAETRG328 at the cleavage site of the haemagglutinin (HA) protein. It was capable of infecting domestic chickens under experimental conditions with a low level of virus excretion via the cloaca and oropharynx following intravenous or oral and oculonasal inoculation. The full-length HA and nucleoprotein (NP) genes of this H6N2 virus were subsequently cloned into the eukaryotic expression vector VR1012 to generate VR-HA and VR-NP constructs. Six-week-old Hy-Line chickens were intramuscularly injected with either the VR-HA or VR-NP vaccine at different dose rates, with or without lipofectin as adjuvant. Minimal or no detectable antibody was produced, as measured by HI, ELISA and Western blotting-based assay, but high titres of H6-specific HI antibodies appeared 10 days after homologous virus challenge. In contrast to the empty vector controls, there was a significant difference in HI antibody titre between pre- and post-challenge in vaccinated birds, indicating some evidence for the priming effect of the DNA vaccines. Using the frequency of virus shedding as an indicator of protection, lower doses (50 or 100 ¦Ìg per chicken) of either adjuvanted VR-HA or VR-NP vaccine significantly reduced virus shedding in oropharyngeal and cloacal swabs compared to higher doses (300 or 500 ¦Ìg per chicken ) or empty vector control chickens. Although two vaccinations with naked VR-HA alone were not sufficient to induce an effective immune response against a homologous virus challenge, further repeat vaccinations and incorporation of adjuvant did lead to the generation of low to moderate HI antibody titres in some chickens and resulted in no or reduced virus shedding after challenge. Next, to examine the effect of expression vector, three different DNA vectors, pCI, pCI-neo and pVAX1 were used to clone the same HA gene and generate three DNA vaccine constructs. Once again, direct intramuscular injection of the three DNA constructs did not elicit measurable H6-specific HA antibody response in Hy-Line chickens but the 100 µg pCI-HA lipofectin adjuvanted vaccine group showed a significant increase in post-challenge HI titres from the naive control group, indicating that an anamnestic antibody response had been induced by the pCI-HA DNA vaccination. Compared with the controls, the three DNA constructs showed significantly reduced virus shedding in cloacal swabs post virus challenge, suggesting that the three DNA vaccines induced some level of immune response in vaccinated chickens. As with the VR-HA construct, the lower dose groups for each vaccine (50 or 100 g) were more effective at reducing virus shedding from the cloaca than the higher dose group (300 g). To further investigate why the DNA vaccines did not elicit a measurable antibody response, the HA gene incorporating a Kozak enhancer sequence was cloned into an alternative expression vector, pCAGGS, to produce the pCAG-HAk construct. Three-week-old SPF chickens were immunized with this construct either by the intramuscular route (IM) or electroporation (EP). H6 HI antibodies were present in some chickens by 3 weeks after the first IM vaccination and 75% of the chickens vaccinated with 10, 100 or 300 µg pCAG-HAk were antibody positive by 2 weeks after the second IM vaccination. For EP immunization, 87.5% of vaccinated birds seroconverted after the first vaccination and 100% seroconverted after the second vaccination and the H6 HI antibody titres were significantly higher than for chickens vaccinated by IM inoculation. Another group was given a single dose IM vaccination with 100 µg of the pCAG-HAk construct and showed a maximum sero-conversion rate of 53.3% with a peak H6 HI titre of 27 at 5 weeks post-vaccination. This demonstrated that optimization of the expression vector and insertion of a Kozak sequence could synergistically enhance expression of the H6 HA gene and result in a measurable H6 antibody response in SPF chickens. EP was also compared with IM inoculation with the 100 g pCI-HA construct in SPF chickens, resulting in a 50% sero-conversion rate and mean HI titre of 21.3 at 2 weeks after the second vaccination by EP. By comparison, only 25% chickens had trace HI titres by IM inoculation. This indicated that EP was more efficient than IM delivery for both constructs. A codon-optimized complete HA gene from A/coot/WA/2727/79 (H6N2) was then chemically synthesized and cloned into a pCAGGS vector to generate the pCAG-optiHAk construct. SPF chickens immunized twice with either 10 µg or 100 µg of pCAG-optHA showed 37.5% and 87.5% sero-conversion rates respectively, with a mean H6 HI tire of 21.4 and 22.6 at 3 weeks after the second immunization, but the differences were not statistically significant. There were also no significant differences in either the sero-conversion rate or the H6 HI titre between the pCAG-HAk and pCAG-optiHAk groups, suggesting that a codon-optimized HA DNA vaccine did not achieve significantly better immunogenicity than the pCAG-HAk vaccine. In vitro expression of the developed DNA constructs in chicken-, hamster-, monkey- and human-origin cells, as measured by Western blotting and immunofluorescence testing (IFT), showed the strength of H6 HA expression in the following descending order - pCAG-optiHAk/pCAG-HAk, pCI-HAk, VR-HA, pCI-HA, pCIneo-HA and pVAX-HA. The in vivo chicken vaccinations also showed that the pCI-HA construct was more effective than the pCI-neo-HA, and that the pCAG-optiHA or pCAG-HAk constructs were better than pCI-HAk in term of reduction in virus shedding after H6N2 virus challenge. Thus, in vitro HA gene expression directly correlated with the generation of immune responses in vivo, indicating that in vitro studies can be used for pre-selection of expression plasmids prior to development of avian influenza DNA vaccines. Lipofectin as a chemical adjuvant was shown to enhance the DNA-induced immune response but is prohibitively expensive for routine use in poultry vaccines. Thus, an experimental adjuvant for poultry DNA vaccines (Essai) and a new nanoparticle (Phema) adjuvant used for the first time in poultry were compared with conventional aluminum salts (alum) adjuvant in the present study. No HI antibody was detected in any adjuvant-vaccinated Hy-Line chickens following two immunizations. However, in comparison with the naive control group, the alum- and Phema adjuvanted pCAG-HAk groups significantly reduced the frequency of virus shedding in oropharyngeal swabs, but Essai adjuvant was not effective in augmenting the pCAG-HAk vaccine efficacy. This pilot study also emphasised that the traditional aluminum hydroxide adjuvant, either DNA binding or non-binding, may be useful as an adjuvant for enhancing DNA-induced immune responses in chickens owing to its low price and safety record. Overall, DNA immunization with various HA-expressing constructs was shown to be variably effective in inducing immune responses in chickens. The efficacy of DNA vaccines could be synergistically improved by taking appropriate approaches. With continuing research DNA vaccines have the potential to become an important tool for disease prevention and control.

Genetic immunization, also known as DNA or polynucleotide immunisation, is well documented to induce broad-based immunity in various animal models of infectious and non-infectious diseases. However, the low potency of DNA vaccines has to date precluded the development of commercial vaccines. The aim of this study was to systematically investigate a number of parameters to improve the potency of DNA vaccines for use in chickens, using a low pathogenic avian influenza (LPAI) virus as a proof-of-concept for their ability to produce a humoral immune response. The index virus used in the study was avian influenza virus A/coot/WA/2727/79 (H6N2), isolated from an apparently healthy Eurasian coot in 1979. Prior to any DNA experiments the virus was rigorously characterized. The virus strain was shown to be an H6 subtype by haemaglutination inhibition (HI) testing and as an N2 subtype by gene sequence analysis. The isolate was shown to be able to grow on MDCK cells in the absence of exogenous trypsin. It was further biologically characterized as LPAI with an intravenous pathogenicity index (IVPI) of 0.15 and a motif of 321PQAETRG328 at the cleavage site of the haemagglutinin (HA) protein. It was capable of infecting domestic chickens under experimental conditions with a low level of virus excretion via the cloaca and oropharynx following intravenous or oral and oculonasal inoculation. The full-length HA and nucleoprotein (NP) genes of this H6N2 virus were subsequently cloned into the eukaryotic expression vector VR1012 to generate VR-HA and VR-NP constructs. Six-week-old Hy-Line chickens were intramuscularly injected with either the VR-HA or VR-NP vaccine at different dose rates, with or without lipofectin as adjuvant. Minimal or no detectable antibody was produced, as measured by HI, ELISA and Western blotting-based assay, but high titres of H6-specific HI antibodies appeared 10 days after homologous virus challenge. In contrast to the empty vector controls, there was a significant difference in HI antibody titre between pre- and post-challenge in vaccinated birds, indicating some evidence for the priming effect of the DNA vaccines. Using the frequency of virus shedding as an indicator of protection, lower doses (50 or 100 ¦Ìg per chicken) of either adjuvanted VR-HA or VR-NP vaccine significantly reduced virus shedding in oropharyngeal and cloacal swabs compared to higher doses (300 or 500 ¦Ìg per chicken ) or empty vector control chickens. Although two vaccinations with naked VR-HA alone were not sufficient to induce an effective immune response against a homologous virus challenge, further repeat vaccinations and incorporation of adjuvant did lead to the generation of low to moderate HI antibody titres in some chickens and resulted in no or reduced virus shedding after challenge. Next, to examine the effect of expression vector, three different DNA vectors, pCI, pCI-neo and pVAX1 were used to clone the same HA gene and generate three DNA vaccine constructs. Once again, direct intramuscular injection of the three DNA constructs did not elicit measurable H6-specific HA antibody response in Hy-Line chickens but the 100 µg pCI-HA lipofectin adjuvanted vaccine group showed a significant increase in post-challenge HI titres from the naive control group, indicating that an anamnestic antibody response had been induced by the pCI-HA DNA vaccination. Compared with the controls, the three DNA constructs showed significantly reduced virus shedding in cloacal swabs post virus challenge, suggesting that the three DNA vaccines induced some level of immune response in vaccinated chickens. As with the VR-HA construct, the lower dose groups for each vaccine (50 or 100 g) were more effective at reducing virus shedding from the cloaca than the higher dose group (300 g). To further investigate why the DNA vaccines did not elicit a measurable antibody response, the HA gene incorporating a Kozak enhancer sequence was cloned into an alternative expression vector, pCAGGS, to produce the pCAG-HAk construct. Three-week-old SPF chickens were immunized with this construct either by the intramuscular route (IM) or electroporation (EP). H6 HI antibodies were present in some chickens by 3 weeks after the first IM vaccination and 75% of the chickens vaccinated with 10, 100 or 300 µg pCAG-HAk were antibody positive by 2 weeks after the second IM vaccination. For EP immunization, 87.5% of vaccinated birds seroconverted after the first vaccination and 100% seroconverted after the second vaccination and the H6 HI antibody titres were significantly higher than for chickens vaccinated by IM inoculation. Another group was given a single dose IM vaccination with 100 µg of the pCAG-HAk construct and showed a maximum sero-conversion rate of 53.3% with a peak H6 HI titre of 27 at 5 weeks post-vaccination. This demonstrated that optimization of the expression vector and insertion of a Kozak sequence could synergistically enhance expression of the H6 HA gene and result in a measurable H6 antibody response in SPF chickens. EP was also compared with IM inoculation with the 100 g pCI-HA construct in SPF chickens, resulting in a 50% sero-conversion rate and mean HI titre of 21.3 at 2 weeks after the second vaccination by EP. By comparison, only 25% chickens had trace HI titres by IM inoculation. This indicated that EP was more efficient than IM delivery for both constructs. A codon-optimized complete HA gene from A/coot/WA/2727/79 (H6N2) was then chemically synthesized and cloned into a pCAGGS vector to generate the pCAG-optiHAk construct. SPF chickens immunized twice with either 10 µg or 100 µg of pCAG-optHA showed 37.5% and 87.5% sero-conversion rates respectively, with a mean H6 HI tire of 21.4 and 22.6 at 3 weeks after the second immunization, but the differences were not statistically significant. There were also no significant differences in either the sero-conversion rate or the H6 HI titre between the pCAG-HAk and pCAG-optiHAk groups, suggesting that a codon-optimized HA DNA vaccine did not achieve significantly better immunogenicity than the pCAG-HAk vaccine. In vitro expression of the developed DNA constructs in chicken-, hamster-, monkey- and human-origin cells, as measured by Western blotting and immunofluorescence testing (IFT), showed the strength of H6 HA expression in the following descending order - pCAG-optiHAk/pCAG-HAk, pCI-HAk, VR-HA, pCI-HA, pCIneo-HA and pVAX-HA. The in vivo chicken vaccinations also showed that the pCI-HA construct was more effective than the pCI-neo-HA, and that the pCAG-optiHA or pCAG-HAk constructs were better than pCI-HAk in term of reduction in virus shedding after H6N2 virus challenge. Thus, in vitro HA gene expression directly correlated with the generation of immune responses in vivo, indicating that in vitro studies can be used for pre-selection of expression plasmids prior to development of avian influenza DNA vaccines. Lipofectin as a chemical adjuvant was shown to enhance the DNA-induced immune response but is prohibitively expensive for routine use in poultry vaccines. Thus, an experimental adjuvant for poultry DNA vaccines (Essai) and a new nanoparticle (Phema) adjuvant used for the first time in poultry were compared with conventional aluminum salts (alum) adjuvant in the present study. No HI antibody was detected in any adjuvant-vaccinated Hy-Line chickens following two immunizations. However, in comparison with the naive control group, the alum- and Phema adjuvanted pCAG-HAk groups significantly reduced the frequency of virus shedding in oropharyngeal swabs, but Essai adjuvant was not effective in augmenting the pCAG-HAk vaccine efficacy. This pilot study also emphasised that the traditional aluminum hydroxide adjuvant, either DNA binding or non-binding, may be useful as an adjuvant for enhancing DNA-induced immune responses in chickens owing to its low price and safety record. Overall, DNA immunization with various HA-expressing constructs was shown to be variably effective in inducing immune responses in chickens. The efficacy of DNA vaccines could be synergistically improved by taking appropriate approaches. With continuing research DNA vaccines have the potential to become an important tool for disease prevention and control.

Inbreeding depression is one of the factors that can increase the risk of extinction of small populations, and therefore understanding its effects is currently an important issue in conservation biology. Until recently, few studies on inbreeding depression were carried out in wild populations. These recent studies have highlighted the variability in detecting inbreeding depression among natural populations and the multitude of factors that can influence its expression. Many of the factors affecting inbreeding depression in wild populations remain largely unexplored and most of the recent studies in this area have tended to focus on incidents of inbreeding in populations with a history of large population size. The aim of this study is to investigate the relative importance inbreeding depression has had on individual fitness parameters in a population of New Zealand's Stewart Island robins Petroica australis rakiura introduced to Ulva Island. This island population has historically gone through several population bottlenecks. Four main factors that potentially influence the rate of inbreeding and the extent of inbreeding depression, were investigated: environmental variability, life history stage, genetic load and dispersal. Generalized Linear Mixed Modelling was first used to determine how weather affected nest survival. Weather effects were then incorporated into models containing demographic factors to control for environmental variability, and finally parental, maternal and paternal inbreeding co-efficients (=f) were added to models to determine the relative importance of inbreeding depression. Interactions between inbreeding depression and environmental factors were explored. Three different life history stages were compared to determine the differences in inbreeding depression at each stage as well as cumulative effects over time. The genetic load of the population was estimated using lethal equivalents allowing for standardised comparison of inbreeding depression with other species. The likelihood of inbreeding in the population was also explored by investigating the factors affecting dispersal patterns and evaluating evidence for inbreeding avoidance. Inbreeding depression was found to be mild in the robin population. Weather did not have strong effects on nest survival or interactions with inbreeding. Female age was the only factor interacting with inbreeding, with younger inbred females experiencing significantly reduced offspring juvenile survival. Parental and paternal f did not significantly affect brood survival at any life history stage, however, maternal f showed significant effects on nest juvenile survival with the strongest effect occurring when survival was examined cumulatively over all life history stages. The Stewart Island robin had a relatively low lethal equivalent value compared to the closely related North Island robin and other avian species. This difference was associated with the Stewart Island robin having a low genetic load, most likely due to historical genetic purging during periods of population bottleneck. The Ulva Island robin population did not appear to be avoiding inbreeding through dispersal. Dispersal distance was most strongly influenced by the location of the natal nest of the dispersing offspring. In conclusion, the genetic history of the population was likely to have had the strongest impact on the severity of inbreeding depression in the Ulva Island robin population. The results of the thesis highlight the need to examine a number of factors to be able to explain variability in inbreeding depression among populations.

1 v.
Title page, contents and abstract only. The complete thesis in print form is available from the University Library.
Thesis (Ph.D.)--University of Adelaide, Dept. of Crop Protection, Waite Agricultural Research Institute, 1992

[Truncated abstract] The dibbler, Parantechinus apicalis, is an endangered marsupial that exists on Boullanger, Whitlock and Escape islands off Jurien Bay in Western Australia. The introduced house mouse, Mus domesticus, exists on Boullanger and Whitlock islands, and the King’s skink, Egernia kingii, inhabits Boullanger and Escape islands. The grey-bellied dunnart, Sminthopsis griseoventer, exists on Boullanger Island. Over the last 150 years, the wedge-tailed shearwater, Puffinus pacificus, has colonised the islands to varying degrees. The interaction between dibblers and other island species is not clear. The purpose of this study was to determine the main factors regulating the dynamics of mammals, and in particular dibblers, on the Jurien islands. This was achieved by examining the effect of seabirds, the competitive interactions between species living on the islands, and seasonal changes in the environment. Animals were trapped for a period of 30 months, and their population structure, body condition, longevity, habitat preferences, diet and ecophysiology were examined. The results presented support the theory that by increasing soil nutrient concentrations, burrowing seabirds increase the primary productivity of islands, which has flow on effects to other trophic levels. Densities of seabirds and soil nutrient concentrations were highest on Whitlock Island, intermediate on Escape Island, and lowest on Boullanger Island . . .Thirty-five percent of dibblers on Escape Island were missing their tail or a limb, probably as a result of aggression from King’s skinks. Competition from high numbers of house mice on Boullanger Island, and from high numbers of King’s skinks on Escape Island, may increase the occurrence of male die-off on these islands. The better body condition and greater longevity of dibblers on Whitlock Island, despite high numbers of house mice, suggests that abundant resources are available to sustain both species. This study demonstrates that high densities of seabirds positively affect the population dynamics of mammals on the Jurien islands. Burrowing seabirds appear to influence the dynamics of dibblers more so than competition from house mice or King’s skinks. The findings from this study will assist the Dibbler Recovery Team with future management decisions regarding the viability of dibblers on the Jurien islands, and with decisions regarding the necessity to control house mouse numbers in the presence of native species.

[Truncated abstract] Ecosystem engineers are organisms that physically modify habitat in a manner that modulate resource flows and species within ecosystems. Ecosystem engineering is distinct from classical interactions (competition, predation, parasitism and mutualism) in that it does not involve direct trophic exchange between organisms. The term ‘ecosystem engineer’ is a recently adopted one, and we are just beginning to investigate the occurrence and impact of engineers in ecosystems. My thesis explores the ecosystem engineering actions of Wedge-tailed Shearwaters, Puffinus pacificus, in a Mediterranean island, heathland ecosystem. I have approached this by (1) describing and quantifying the physical impact of these engineers, and (2) describing and quantifying the effects that these actions have on three major ecosystem components: the soil, the vascular plants, and the vertebrate fauna. Wedge-tailed Shearwaters are procellariid seabirds that excavate nesting burrows on offshore islands. The birds are colonial nesters, and on Rottnest Island, 17 km off the mainland coast of south-western Western Australia, their colonies have expanded considerably in recent decades. The expansion fits the trend observed in other tropicalorigin seabirds that breed in south-western Australia. In the last ten years, two new colonies have appeared (in a total of six) and the number of burrows on the island has almost doubled, to 11 745 ± 1320SE. In the same period the area occupied by the birds has increased by almost half ...

In an era of acute concern about airline safety, bird strikes are still one of the major hazards to aviation worldwide. The severity of the problem is such that it is mandatory in all developed countries to include bird management as part of airport safety management programs. In Australia, there are approximately 500 bird aircraft strikes per year (Bailey 2000). Brisbane airport has a relatively high occurrence of strikes, with an average of 77 recorded every year (2002-2004). Given the severity of the problem, a variety of techniques have been employed by airports to reduce bird strikes. Scare devices, repellents, continuous patrols for bird hazing, use of raptors to clear airspace of birds and depredation are used by many airports. Even given the diversity of control methods available, it is accepted that habitat management is the most effective long term way to control birds in and around the airport space. Experimental studies have shown that habitat manipulation and active scaring measures (shooting, scaring etc), can reduce bird numbers to an acceptable level. The current study investigated bird populations in six major vegetation habitat types identified within the operational and surrounding areas of Brisbane airport. In order to determine areas where greater bird control and management should be focused, bird abundance, distribution, and activity were recorded and habitats that pose the greatest bird strike risk to aircraft were identified. Secondly, species with high hazard potential were identified and ranked according to their hazard potential to aircraft. This study also investigated the effectiveness of different vegetation management options to reduce bird species abundance within operational areas of Brisbane airport. Four different management options were compared. Each management option was assessed for grass structural complexity and potential food resources available to hazardous bird species. Analysis of recorded data showed that of the habitats compared within the Brisbane airport boundaries, grasslands surrounding runways, taxiways and aprons possess the greatest richness and abundance of bird species that pose the greatest potential hazard to aircraft. Ibis and the Australian kestrel were identified as the bird species that pose the greatest risk to aircraft at Brisbane airport, and both were found in greatest numbers within the managed grasslands surrounding operational areas at the airport. An improved reporting process that allows correct identification of all individual bird species involved in bird strikes will not only increase the accuracy of risk assessments, but will also allow implementation of more effective control strategies at Brisbane airport. Compared with current grassland management practice, a vegetation management option of maintaining grass height at 30-50cm reduced total bird utilisation by 89% while utilisation of grassland by potentially hazardous birds was also reduced by 85%. Maintaining grass height within the 30-50cm range also resulted in a 45% reduction in the number of manipulations required per year (11 to 6), when compared with current management practices, and a 64% reduction in annual maintenance cost per hectare. When extrapolated to the entire maintained grass area at Brisbane airport, this resulted in a saving of over $60 000 annually. Optimisation of potential hazard reduction will rely on future studies that investigate the effect of particular vegetation species that could replace the existing mix of grasses used at Brisbane airport and an understanding of the relative importance of vegetation structure and food supply in determining utilisation by potentially hazardous bird species.

Nature-based tourism offers significant socio-economic incentives to successfully replace more intrusive land uses but also causes negative environmental impacts. Currently, knowledge is needed about the effectiveness of specific management actions such as the provision of different access modes and tour experiences at minimizing these impacts while maximizing visitor satisfaction. Nature-based tourism activities were studied in the species-rich gorges of the Flinders Ranges in Outback Australia. This study developed a conceptual framework of visitor-environment relationships, constructed a regional visitor profile, assessed visitor monitoring methods to quantify usage intensity in relation to the access mode (roads vs. hiking trails), examined changes in vegetation and bird communities in relation to usage intensity and access mode, tested effects of approach behaviour among driving vs. hiking tourists on kangaroo behaviour, and designed a framework for a night-time wildlife tour. The usage intensity of gorge sections was best determined from visitor numbers stratified by their behaviour, as the access mode fundamentally changed visitor behaviour in gorges. High compared to low usage recreational tracks altered species community composition, decreased total plant cover, increased non-native species cover, increased or decreased plant diversity depending on the track distance, increased soil compaction, and decreased bird numbers and species richness. Vegetation changes had secondary aversive effects on the bird community. The magnitude and spatial extent of these community impacts were greater along roads than trails. Visitor approach towards kangaroos varied with the access mode and necessitated individual recommendations for low-impact behaviour. The optimal night-time observation tour employed night-vision devices and bat detectors and coupled visitor satisfaction with low impact on wildlife. A range of factors (e.g., weather conditions) moderated the susceptibility of the wildlife to tourism disturbance. To protect wildlife and habitat along recreational tracks in arid-lands gorges, it is recommended to (1) monitor usage intensity and the identified impact indicators within their effect zone, (2) curtail gorge usage by restricting vehicle access to sections and regulating high impact activities (e.g., wild camping), (3) base environmental education upon scientifically tested low-impact visitor behaviour, and (4) engage with tourism operators in the design of low-impact, yet satisfying tours based on scientific principles.

Deserticolous birds inhabit an environment characterised by high ambient temperatures and low rainfall that has low primary productivity. The combination of these factors may lead to the evolution of adaptations that minimise food and water requirements. One physiological adaptation that has been found in many deserticolous birds is the reduction of basal metabolic rate (BMR). I measured metabolic rate in the laboratory using four species of African lovebirds (Agapornis) , and four species of Australian grass parakeets (one Neopsephotus and three Neophema), all similar in body mass. Tests for differences between groups were carried out using both conventional and phylogenetically independent methods. The BMRs of the lovebird and grass parakeet species were not statistically correlated with habitat type. These results confirm the findings of previous studies on the effect of desert conditions on the BMR of parrots. I also found no significant differences in BMR between the species assemblages from different continents. The lack of significant differences in BMR between deserticolous and nondeserticolous parrots supports the idea that birds are "ex-adapted" to living in desert environments. I suggest that the results may have been affected by phenotypic plasticity in BMR, as recent evidence has shown that the scaling exponent of BMR differs between captive-raised and wild-caught birds. To elucidate the effect of origin (captive-raised vs. wild-caught) on the BMR of birds used in this study a large scale analysis of bird BMR data was undertaken. BMR and body mass data for 242 species of birds were obtained from the literature, this study, and unpublished data from various sources. A phylogeny was constructed using molecular and morphological phylogenies from the literature, and analysed using conventional and phylogenetically independent methods. The conventional analysis found significant differences in the scaling exponents of BMR of captive-raised and wild-caught birds. However the phylogenetically independent method showed non-significant differences between these two groups. Conventional analysis of differences between parrots and all other birds yielded significant differences between these two groups, with parrots having significantly higher BMRs than other birds. Again the phylogenetically independent analysis found non-significant differences between these VII two groups. A test of homogeneity of variance between these two groups found significant differences between the variances ofthe two groups, probably due to disparity in sample size and range of body sizes. The conventional and phylogenetically independent tests for differences between captive-raised and wild-caught parrots yielded non-significant results, suggesting that the parrots are not subject to the phenotypic adjustments postulated for all other birds. The lack of significant differences between captive-raised and wild-caught parrots suggests that the analyses of differing habitat type for African and Australian parrots is indeed valid.
Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.

The work presented in this thesis aimed to do the following : 1. investigate the cause of decline of the three Melithreptus species of the Mt Lofty Ranges, with a particular emphasis on M. gularis due to its critical status in the ranges ; 2. investigate the ecology and behaviour of sympatric M. brevirostris and M. lunatus populations in the Mt Lofty Ranges ; and 3. suggest management options for the three species. Further, it became clear through the course of the project that an understanding of the decline in Melithreptus required : 1. comparisons with other honeyeater species, particularly widespread and abundant honeyeater species. Three species of Melithreptus occur in the Mt Lofty Ranges : Brown - headed Honeyeater Melithreptus brevirostris ; White - naped Honeyeater Melithreptus lunatus ; and Black - chinned Honeyeater Melithreptus gularis. Since at least the 1970 ' s all three species have been in decline within the ranges. One species has been reduced in both abundance and distribution within the region ( M. gularis ), while the other two are now recognised as having reduced in abundance. Melithreptus species in the Mt Lofty Ranges are sympatric with strikingly similar ecology. Melithreptus gularis is the largest of the three, while M. brevirostris and M. lunatus are almost identical in weight, feeding behaviour and morphology. Despite their similarities no studies have closely examined their ecology in sympatry and no studies have examined possible causes of their decline. Interspecific competition is thought to be important in the organisation of honeyeater communities. Studies of nectarivore communities suggest a number of ways in which competition causes the component species to partition resources : size ; beak length ; habitat ; and behaviour, which includes a mix of social and feeding strategies. Due to its role in honeyeater community organisation, changed level of interspecific competition has been highlighted as a possible cause of decline in some honeyeater species in the woodlands of southern Australia. Both interference competition and exploitative competition have been highlighted in various situations ( Ford et al. 2001 ). Given the hypothesised role of interspecific competition in the decline of honeyeater species and the declining status of all the Melithreptus in the Mt Lofty Ranges the genus appeared to provide a good basis for examining the hypothesis that interspecific competition is contributing to the decline of some honeyeater species through exclusion from resources and / or reduction in resources available. ( Ford et al. 2001 ) give the following as potential tests for their interspecific competition hypothesis : 1. examine community structure for ' forbidden combinations ' ( pairs of species that rarely occur together ) ; 2. compare time spent in interspecific competition ( interference ), and foraging in fragmented and continuous habitat ; 3. measure seasonal and spatial patterns of resource abundance and depletion ; and 4. remove competitors and observe response in abundance and behaviour of other species. These suggestions form the basis for much of the work presented in this thesis. An initial survey examined not only community structure for forbidden combinations, but also investigated other possible causes of decline, based on literature for both declining woodland birds and Melithreptus. Besides interspecific competition, other possible causes included insufficient preferred habitat, insufficient food resources and landscape fragmentation. Repeated counts of honeyeaters at 90 sites of one hectare in the Mt Lofty Ranges were undertaken over a one year period. Melithreptus lunatus was found to be more abundant where certain eucalypt species occurred ( particularly E. viminalis ), although this was postulated to be a reflection of productive soils. Melithreptus brevirostris was found to be more abundant where Phylidonyris novaehollandiae ( New Holland Honeyeater ) was most abundant, despite P. novaehollandiae also being the most widespread and abundant honeyeater in the Mt Lofty Ranges. Thus, the survey work did not find forbidden combinations of honeyeaters. However , the scale at which the survey work was undertaken ( sites of 1ha ) may have masked any competition between species due to spatial heterogeneity. At the scale of one hectare there is likely to be areas of resource not used by other honeyeaters, allowing Melithreptus to avoid feeding territories of aggressive honeyeaters. Therefore, in order to more thoroughly investigate competition between P. novaehollandiae and Melithreptus, a removal experiment with finer resolution than 1ha was carried out. This demonstrated that P. novaehollandiae do prevent M. lunatus from using certain areas of the landscape. A final examination of interactions between Melithreptus and widespread and abundant honeyeaters was carried out in the form of a survey in which individual trees were watched and visits by honeyeater species timed. Based on observations of Melithreptus, it appeared that generally M. brevirostris groups used a swamping strategy to access defended resources, whereas M. lunatus moved quietly, often as individuals or pairs. Thus the two species were hypothesised to use two different behavioural strategies to access defended resources, termed stealth ( the use of secretive behaviour to access resources that are being protected ) and swamping ( the use of a combined direct approach by a number of individuals to access resources that are being protected ). Based on estimations of the standardised protection of resources for individual trees, M. lunatus were able to access defended resources for longer, while M. brevirostris were able to access better defended resources but for a shorter time. These results were consistent with the hypothesis of two different behavioural strategies for accessing defended resources. Both species may employ both strategies, but M. brevirostris more often use swamping, and M. lunatus more often use stealth. Investigating the morphology of the small honeyeaters of the Mt Lofty Ranges confirmed that size and beak length were important in discriminating between most species. However, these did not provide any basis for separating the Melithreptus. Closer examination of morphology between M. brevirostris and the M. lunatus sexes revealed further similarities to those previously documented. The average values for many morphological attributes of M. brevirostris fell between the average value for the M. lunatus sexes, suggesting that ecologically the three species / sexes formed a continuum. The M. lunatus sexes and M. brevirostris were then referred to as the small Melithreptus guild ( it was not possible to sex M. brevirostris based on the range of attributes measured ). The greatest differences between the small Melithreptus guild were found in wing length and leg morphology. The direction of the differences suggested that M. brevirostris would be more similar to female M. lunatus in movements and more similar to male M. lunatus in foraging behaviour. These two aspects of Melithreptus ecology were the subject of the last and most extensive phase of the project. Movements were investigated for Melithreptus at four sites in the Mt Lofty Ranges using radio - telemetry techniques. Melithreptus were found to use large areas of the landscape and to have large core areas of activity within their home range. Using the same methods confirmed that Melithreptus had larger home ranges ( mean 100 % minimum convex polygon 23 hectares ) than P. novaehollandiae ( mean 100 % MCP 5 hectares ), and larger home ranges than those reported in the literature for other honeyeater species. Data on a single M. gularis ( 100 % MCP 140 hectares ) suggest that this species has even larger home range requirements. Information from colour - banded birds suggests that most M. brevirostris and male M. lunatus had stable core areas of activity over the period of this study, while female M. lunatus were less likely to have stable core areas of activity, particularly during the non - breeding season. A trend in home range and movement data was consistent with the hypothesis that M. brevirostris was more similar to female M. lunatus than to male M. lunatus. Behaviour of Melithreptus and P. novaehollandiae were investigated using time budget techniques. Melithreptus were found to spend most of their day foraging ( up to 84 % ), very little time resting ( as little as 1.8 % ) and very little time in aggression ( as little as 0.6 % ). These values are each within the outer range of results published on other honeyeaters. Melithreptus gularis behaviour was very similar to both M. brevirostris and M. lunatus. Melithreptus appear to forage predominantly from poor quality resources, requiring a large proportion of their time allocated to foraging. The small proportion of time spent resting is probably a result of the time spent foraging. The small proportion of time spent in aggression is partly the result of a lack of aggression by Melithreptus, but is also potentially due to their knowledge of aggression levels within their home range and their use of stealth and swamping. Melithreptus are likely to avoid the most highly protected ( and therefore the most productive ) areas within their home ranges. A trend in behavioural data was consistent with the hypothesis that M. brevirostris was more similar to male M. lunatus than to female M. lunatus. Based on the data collected in this study, Melithreptus in the Mt Lofty Ranges are characterised by : relatively large home range size with core areas that are used over extended periods of time ; similar foraging behaviour and morphology ; lack of aggression ; and ( probably ( complex social behaviour. Their decline in the Mt Lofty Ranges can be attributed to the preferential clearance of their preferred habitat, their requirement for a large home range and their predominant use of poor quality resources, particularly in comparison to other, locally successful honeyeaters. The final aim of this work on Melithreptus honeyeaters in the Mt Lofty Ranges was to provide options for managing remaining Melithreptus populations, in particular M. gularis which according to informed observers is now critically endangered in the region. Due to the extent of habitat clearance in the Mt Lofty Ranges, the decline of Melithreptus will only be addressed in the long term through large scale revegetation projects. Melithreptus requirements in any large scale revegetation are most likely to be met by providing a range of eucalypt species. In the short to medium term, management actions may be needed to prevent the loss of M. gularis from the region. Given the findings of this study, there are few such options available. The management of woody weeds in known Melithreptus home ranges is suggested as one possible management strategy. Melithreptus rarely use a shrub layer for foraging, shelter or nesting, whereas P. novaehollandiae use a shrub layer for each of these activities. Thus, where grassy woodlands have been invaded by woody weeds, P. novaehollandiae potentially have an increased year round presence.
Thesis (Ph.D.)--School of Earth and Environmental Sciences, 2005.

Since European settlement, the woodlands and associated habitats, especially in the temperate zones of Australia, have been extensively cleared and converted to arable land and pastures. Much of the remaining vegetation in the agricultural zone occurs as small isolated patches prone to disturbance and degradation. Apart from habitat loss and fragmentation, altered fire regimes, periods of intense drought, and the introduction of exotic plants and animals, have contributed to the deterioration of most of the natural habitats across Australia, with a negative impact on the native wildlife, including birds. Many woodland bird species have undergone widespread declines, culminating in some local or even regional extinctions. In the mallee woodlands of south-east Australia two closely related species of whistlers (fam. Pachycephalidae) — Red-lored Whistler Pachycephala rufogularis and Gilbert’s Whistler P. inornata — have overlapping ranges, and in some areas they co-exist. These two species are morphologically and ecologically similar. However, despite the similarities, P. rufogularis has undergone greater declines in distribution and abundance than P. inornata. The ecology of these two species is poorly known, which renders adequate management impracticable. The major objectives of this thesis were to determine the key habitat requirements for the two species, to determine their habitat use, and to document the ecology and behaviour of the two species, particularly their foraging, and intra- and interspecific interactions. A sound knowledge of the ecology of the two species is needed to underpin appropriate actions for their management and conservation. Morphological features were measured from skins of P. rufogularis and P. inornata in the South Australian Museum collection, and from captured live birds, to detect if any aspect of the morphology could indicate possible niche partitioning between the two species. Also, the use of biometry as a tool for separating the sexes for P. rufogularis, for determining the species of the uncoloured immature birds and for sexing immatures, was evaluated. No morphological feature suggested niche partitioning. The biometry did not prove a very reliable tool for distinguishing sexes in adult P. rufogularis, but reliably identified the species of the uncoloured immatures. Sexing immatures based on biometrical data alone was not possible. Research was conducted in two main South Australian parks: Gluepot Reserve and Ngarkat Conservation Park. Ecological and behavioural data for P. rufogularis and P. inornata were collected by observing marked (colour-banded and radio-tagged) and unmarked individual birds of both species and sexes, over a two-year period from June 2004 to May 2006. The home ranges of P. rufogularis and P. inornata were determined by tracking the movements of birds in the landscape. Pachycephala rufogularis had much larger home ranges than P. inornata, especially when breeding. The striking differences in home range size between the two ecologically similar species might be related to differences in site fidelity. Pachycephala rufogularis at Gluepot was sedentary, being detected in the same locations throughout the year, and over several years. On the contrary, P. inornata generally showed poor site fidelity, being more mobile, and shifting home ranges between and within seasons. In the field the two species were segregated by habitat. Pachycephala rufogularis and P. inornata showed different habitat preferences, even in areas where they did not co-occur. Pachycephala rufogularis favoured low mallee with Triodia on sand dunes, while P. inornata favoured tall mallee with sparse shrub understorey in interdunes, but also other habitats, such as prickly Acacia thickets and Casuarina woodlands. However, both species used the mallee- Triodia with Callitris vegetation type. The key to coexistence in this habitat was a behavioural one, P. inornata acting as a subordinate species. Pachycephala rufogularis had strict habitat requirements, with the presence of Triodia being critical for the presence of the species. In contrast, P. inornata was more flexible in its habitat requirements, and used a broader range of vegetation types, being more of a habitat generalist. The investigation of habitat use from both a spatial and temporal perspective confirmed that both species actively selected habitat, and that the habitats they selected differed. The core areas of home ranges predominantly contained the preferred habitat for both species. In both species, core areas of home ranges of breeding individuals (where generally the nests were placed) contained preferred habitat in higher proportion than core areas of non-breeding birds. This suggests that during breeding, both species are more restricted to, and/or use more intensely the preferred habitat than when not breeding. The foraging behaviour did not differ consistently between the two species, both capturing insects mostly by snatching in canopy foliage, and also by gleaning on the vegetation, at different heights. However, the two species were already segregated by habitat. Thus the resource partitioning occurred spatially, at the macrohabitat level. In the instances when individuals of both species foraged in the same area and used the same resources, resource partitioning occurred at a temporal scale. Both species were generalists in foraging; therefore, a presumed foraging specialisation as a possible factor related to the decline of P. rufogularis was ruled out. Pachycephala rufogularis and P. inornata are unlikely to be competitors. Support for this argument came from the situation at Ngarkat, where P. inornata was absent. Despite this, P. rufogularis did not use a broader range of vegetation types in Ngarkat, as would be expected under ‘competitive release’. Instead the species maintained strict habitat requirements, specializing virtually on a single vegetation type. The rigid habitat requirements of P. rufogularis, together with its sedentary nature, render this species vulnerable to disturbances, such as wildfires. On the other hand, the apparent flexibility in habitat requirements and greater mobility may explain why P. inornata has been more successful than its sibling species. The information on habitat requirements, preference and use, and also on home ranges of P. rufogularis and P. inornata provided in this study should be included in future habitat suitability models and predictive models for these species, which will assist in their management.
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Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2009

碩士
國立臺灣大學
森林環境暨資源學研究所
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To examine the effects of environmental factors on breeding and non-breeding bird species richness, this study compiled distribution ranges of 3,599 bird species and environmental factors in the region between 70° E and 180° E. The breeding and non-breeding distribution ranges of bird species were transformed into 96.3 × 96.3 km grid system. Enhanced vegetation index (EVI), temperature, precipitation, latitude, range of elevation, land area, and distance to mainland within each grid were calculated. Generalized linear regression analyses by model selection method were used to select best models for interpreting breeding and non-breeding bird species richness. The effects of environmental factors on bird species richness were examined by path analysis. Results revealed that, in mainland East Asia, summer EVI was strongly positively correlated with breeding bird species richness (BSR), and winter temperature was strongly positively correlated with non-breeding bird species richness (NSR). In Australia, summer EVI was strongly positively correlated with BSR, and winter precipitation was strongly positively correlated with NSR. The seasonal change in temperature was the most important factors for the seasonal difference of species richness in East Asia and Australia. Bird species richness of islands was affected by different set of environmental factors, among which island area and temperature were most important. In brief, positively species-energy relationship was obvious in both BSR and NSR. Primary productivity was strongly and positively correlated with BSR, and temperature was strongly positively and positively correlated with NSR. The seasonal change in temperature should be the main force to drive the migration. The effects of environmental factors on bird species richness vary in different regions.

Bibliography: leaves 108-113. This dissertation givens and analytical overview of the research and recovery actions for the Orange-bellied Parrot and the Kangaroo Island Glossy Black-Cockatoo and evaluates the successful practices and those which have failed. This research shows that new recovery action initiatives can still be found and that not all recommendations in recovery plans are followed, which impairs the efficiency of the recovery efforts. It concludes that a successful recovery effort of these two bird species lies in continued research, a serious compliance with the recommendations made by recovery plans and by further environmental education in society.

Bird Island is a former flood tide delta occurring in the mouth of the River Murray, Encounter Bay, South Australia. The island has experienced a rapid development history; in around 60 years the formerly ephemeral deltaic deposits have rapidly become stabilised, forming a permanent island approximately 1 km in diameter.
It has been possible to place tight time restraints on the progressive development of Bird Island over this 60 year period. Its sand dunes and marshes of different ages can be distinguished clearly from an analysis of successive aerial photographs. Evidence suggests they represent different phases in the growth and development of the island, resulting from an interplay of factors including the position and migration of the Murray Mouth relative to the island as well as the availability of sediment and conditions conducive to aeolian sand transport.
The landforms of Bird Island present a unique opportunity for the assessment and study of progressive plant colonisation and succession on a pristine landscape in a coastal/estuarine setting. Bird Island comprises 19 different dune and marsh vegetation types. Research has identified several trends suggesting that the environmental gradients associated with the marsh-dune landforms has influenced some characteristics of species distribution. It also appears that in a general way, species distributions may represent succession on the sand dunes, but this was not as clearly demonstrated across the marshes of different ages on Bird Island.
Research suggests that the construction of the lower River Murray barrages in 1940, which has reduced the median annual flow to the estuary by nearly 75%, and has reduced the tidal prism by up to 90%; has facilitated the development of Bird Island. Bird Island contributed to the closure of the mouth of the River Murray in 1981; inlet behaviour not demonstrated in the 100 years prior to barrage construction according to the results of this research.
The continuing development of Bird Island suggests considerable potential for more blockages in the future. The continuing sedimentation in the Murray Mouth reflects the inability of the current flow regime and marine processes in maintaining the mouth as they did prior to the construction of regulatory works on the Lower River Murray.
Thesis (MApSc(EnvironmentRecreationMg))--University of South Australia, 2004