Academic literature on the topic 'Australian magpies'

AbstractAttacks by participants of conflicts against a third party are referred to as redirected aggression. Usually the third party is a conspecific — few documented cases of redirected aggression against other species exist. The Australian magpie (Gymnorhina tibicen), however, often attacks other species; the reasons for attacks are largely unknown. Some attacks occur after territorial disputes with conspecifics, suggesting that attacks are the result of redirected aggression. We subjected eight Australian magpie groups to simulated territorial intrusions. In one treatment an Australian magpie and rock dove (Columba livia) were presented in cages next to one another (5 m apart) on the territory for 30 min; the Australian magpie decoy was then covered and aggressive responses toward the rock dove by residents were recorded for a further 30 min (Treatment 1). Two additional treatments were presented in an identical manner on each territory where both decoys were either Australian magpies (Treatment 2) or rock doves (Treatment 3). We predicted that if Australian magpies regularly redirect aggression onto benign species after conspecific territorial intrusions, attack rates on the rock dove decoy in Treatment 1 would be higher than attack rates on the rock dove decoy in Treatment 3. Residents were seldom recorded close (<1 m) and not seen attacking rock dove decoys during tests. In contrast, Australian magpie decoys were often approached and attacked by residents. After a decoy was covered (following the first 30 min phase), residents spent little time in close proximity (on cage, <0.3 m, or 0.3-1 m) to the rock dove decoy in either Treatment 1 or Treatment 3; in contrast, residents were often recorded close to the Australian magpie decoy in Treatment 2. We found no evidence that Australian magpies redirect aggression onto other birds after territorial intrusions. The true proportion of territorial disputes leading to redirected attacks may be small, or only occur under highly specific contexts.

Attacks on humans by Australian magpies (Gymnorhina tibicen) cause a significant human–wildlife conflict in suburban environments throughout Australia. Community opposition to lethal control methods generally has, in part, led to an increase in the use of translocation as an alternative. We assessed the effectiveness and implications of using this approach in the management of aggressive magpie in south-eastern Queensland during 1999 and 2000. A total of 968 (1999) and 707 (2000) magpies were reported by the public, of which 39–45% were able to be investigated by a two-person team working three days per week. A total of 141 magpies were translocated, 31.7% of all birds investigated. Of these, only five (3.5%) returned to the place of capture, and 22 (15.6%) were resighted elsewhere; there was no evidence of 'homing'. Only three translocated birds were subsequently reported as being aggressive towards humans. While extremely effective in reducing the conflict locally, we caution against the indiscriminate use of this method, and suggest that it be seen as one of many options available to wildlife managers.

In eastern Australia, two forms of the Australian magpie occur: a white-backed form and a black-backed form. These two forms hybridise across northern Victoria and into South Australia. In this study the response of territorial magpies to caged intruders was examined. Pairs of adult male magpies were introduced into territories. Both were adult black-backed birds, but in each case one of them had its back painted white. The pair was introduced to each territory twice, with the bird that was painted white differing between times. The experiment was run in a population of black-backed birds and a population in the hybrid zone containing white-backed, black-backed and hybrid birds. In both cases, the residents were more aggressive towards the intruder with the white-back than they were to the black-backed intruder. We suggest that this may be because a white-backed bird posed more of a threat to residents than a black-backed bird.

Australian magpies are the cause of a major wildlife-management conflict in suburban areas throughout Australia. Mitigation of this conflict is becoming increasingly difficult in some locations because of community opposition to the destruction of the birds involved, which remains a common management solution of many wildlife agencies. Translocation – the capture and release elsewhere – of offending birds has been advocated but never seriously evaluated. This study aimed to assess the effectiveness of translocation as a means of eliminating magpie attacks. We also attempted to assess the impact of the approach on both the translocated birds and those remaining in the territory. A total of 20 aggressive magpies, all males, were captured and released at distances 17–150 km from the place of capture. Most birds released more than 30 km away were not seen again; two birds released less than 30 km away returned quickly and were recaptured. A single bird re-established itself on its original territory several months after capture. In many cases, new males had replaced the captured birds within days. There was no evidence of negative behavioural interactions between these males and the resident females or chicks. While the technique is effective in reducing the human–magpie conflict at specific locations, our lack of knowledge of the fate of translocated males, as well as several other issues, suggests that this approach be used only in extreme circumstances.

Although attacks on humans by Australian magpies (Gymnorhina tibicen) are a source of significant wildlife–human conflict in urban areas of Australia, little is known about the patterns of attack by these birds. Such information is essential for the development of sound management plans for this species. We examined the attack behaviour of 48 aggressive magpies from Brisbane during September–October 1999, paying particular attention to the types of intruders targeted. All attacking birds were male. A clear majority (71%) of birds attacked only one intruder type, with about half attacking pedestrians only; similar proportions targeted cyclists (8%) only and mail deliverers (10%) only. While all intruding cyclists and mail deliverers were attacked, magpies did not attack all pedestrian intruders, suggesting possible discrimination within this category. Management implications for these intruder types are discussed.

We studied the ecology of the White-winged Chough and its interaction with the Australian Magpie on the Central Tablelands of New South Wales, Australia, over seven months. Both species are ground foragers and significant prey overlap was assumed. Invertebrate biomass as an index of habitat quality, showed grasslands to be the most valuable of the three habitats, followed by edge and forest habitats. Magpie territories were positioned around the grasslands and therefore were of higher quality than chough territories which were dominated by forest and edge. Magpies actively exclude chough groups from most of the highly valuable grassland habitat, through repeated and persistent attacks. Despite an apparently effective defensive strategy we concluded that the chough was largely excluded from the most attractive habitat in our study area by the magpie. This study highlights the implications of species interactions on the responses of individual species to habitat fragmentation across a landscape. Implications of this study for the validity of present vertebrate habitat models, which ignore the dynamic nature of population behaviour are discussed.

Context On airports, birds often exhibit escape behaviour in response to aircraft. Avian escape behaviours can enable birds to effectively avoid collisions with aircraft, although some are maladaptive and may increase the risk of collision (e.g. erratic flying). Habituation and habituation-like processes among birds potentially mediate the likelihood of aircraft-bird collisions. Moreover, because managers exploit avian escape behaviour to reduce bird–aircraft collision risks, habituation may decrease the efficiency of bird-hazard management. Aims Our aim was to better understand avian behavioural responses to approaching aircraft, which may inform bird-hazard management. Methods We examined the response of Australian magpie, Cracticus tibicen, a species commonly involved in collisions with aircraft, to the noise associated with take-off and landing in three areas: airside, on airport but not airside, and off airport. Key results Magpies responded to aircraft noise in a nuanced way. Take-off produced more responses, and more intense responses, than did landing; both resulted in more frequent, and more intense, responses than did a ‘silent’ control. Responses were least likely, and response latencies were longer, airside, followed by on airport but not airside, and off airport. Intensity of responses was similar across these areas. Conclusions Magpies on the airside were least responsive, and this might influence their strike risk. Implications Given that most wildlife collisions occur during take-off and landing and at low altitudes, and that take-off has greatest overall strike risk, the lack of responsiveness of airside-inhabiting magpies may contribute to collision risk.

Many species exhibit some form of colour variation between groups or individuals, and studies of such colour variation, its genetic basis and functional importance can contribute unique insights into the evolutionary, ecological, demographic and genetic processes affecting the diversity of life. Through the examination of the genetics underlying colour traits, the relative importance of different selective and demographic processes in the evolution and maintenance of a trait can be inferred, enabling scientists to gain a better understanding of what drives evolutionary change in different organisms and environments. Such studies also assist in bridging the gaps in our knowledge about the interactions between genetics and ecology that are involved in phenotypic variation. Understanding the pathways linking genetic and regulatory changes to phenotypic change and evolutionary change through time contributes to our knowledge about how species develop and evolve. The Australian magpie (Cracticus tibicen), is a group-living and territorial passerine bird with a characteristic pied appearance of strongly contrasting patches of black and white plumage. The species has several different plumage forms, delineated by the colour and/or pattern of back feathers; these plumage forms hybridise where their distributions overlap. Distributions of plumage forms are highly discordant with patterns of phylogeographic structure found in this species, making a scenario of allopatric divergence followed by secondary recontact at hybrid zones highly unlikely.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Environment
Science, Environment, Engineering and Technology
Full Text

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.

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.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Australian School of Environmental Studies
Full Text

The Australian magpie (Gymnorhina tibicen) is a large, sedentary, omnivorous passerine. In some populations, individuals live in groups, and some of these groups breed cooperatively. The white-backed magpie (G. t. tyrannica) from the south-eastern corner of the continent, has had relatively little study, and few details are known of its mating system, social structure, and method of parental care. I conducted an observational study on a population of white-backed magpies, recording details of their demography, dispersal, breeding system, and parental care. In conjunction, I conducted a genetic analysis of the population, to determine if the genetic mating system matched the observed social system, to detect instances of extra-group mating, and to sex juvenile birds. Extra-pair paternity (EPP) is a common feature of the mating systems of many birds. The rate of EPP may vary between species, races and populations. I made a comparison of extra-group paternity (EGP) rates between two races of the Australian magpie, to determine if similar mating systems were being employed. The two populations had similar social structure, but differed in group size and dispersal. I predicted that dispersal differences would have a profound effect on the rate of EGP between the populations, as the population with the lower rate of dispersal and higher chance of breeding with a close relative would engage in EGPs more frequently. Eight microsatellite loci were used to determine parentage in the white-backed Australian magpie. The rate of EGP was found to be 44%. Dispersal rates were estimated from observational data. Over half of the juvenile magpie cohort from the previous breeding season leave the territorial group. These results contrast sharply with the results found by other researchers in a population of western Australian magpies (G t. dorsalis). In this population, 82% EGP is recorded and dispersal of juveniles is close to nil. The results indicate that dispersal rate is a potentially important predictor of rates of extra-group fertilisations between populations of this species, and suggest that females maximise their reproductive output by avoiding breeding with close kin. The reproductive success of a male bird is often correlated with measurable traits that predict his intrinsic quality. Females are thought to select mates based on their quality to gain their 'good genes'. Male Australian magpies of the white-backed race were trapped in two breeding seasons. Measurements were taken of morphometric and other characteristics in order to discover whether particular traits of males were associated with: a) number of fledglings produced in the territory per season; b) percentage of offspring sired in the territory; and c) whether females select males for their 'good genes'. The only variable that was correlated with number of territorial offspring was feather lice load. Males with high numbers of lice were less likely to produce territorial fledglings in one season and across both seasons. Males of inferior quality may be subject to increased conspecific territorial intrusions, leading to more time spent on defence, more failed breeding attempts, less time allocated to grooming and thus high parasite loads. Males that produced many territorial fledglings were more likely to gain genetic paternity of at least some of them, although again this was significant for only one season. Also, across both seasons, a high number of females in the group was correlated with increased paternity within the group. The general lack of correlation between the variables and level of genetic paternity may be due to females engaging in extra-group mating primarily to avoid breeding with a close relative rather than to choose a quality male. In this scenario, males would not have to be 'high quality', but merely genetically different to the female's social mate. Extra-group paternity (EGP) can affect paternal effort. It may also influence the helping effort of auxiliary birds in cooperatively breeding species. If helping is driven by kin selection, helpers should decline to provision unrelated young. Relatedness becomes difficult to assess however, when females mate outside the group. Alternative rewards may then become important in helper decisions. In my study population of Australian magpies, 38% of fledglings were sired by males outside the territorial group. In a second population (G. t. dorsalis), 82% of fledglings were sired by extra-group males. I observed within-group male and helper feeding effort over three breeding seasons in the first population and obtained data recorded over a single season in the second population. In both populations, males provisioned young regardless of relatedness, as did helpers. Males provisioned less than the nesting female on average. Paternal effort did not reduce with an increase in the rate of EGP between populations. In the population with intermediate levels of EGP, the white-backed magpies, I observed helpers in about half of the sampled territories that produced fledglings. Helpers did not increase the production of young. In the population with high levels of EGP, western magpies, I detected helping behaviour in proportionally more territories. It appears that Australian magpie helpers provide help in order to pay 'rent' and remain on the natal territory. I discuss these results in light of the differences between the two races of magpie and the major theories regarding male parenting decisions and helper activity. Finally, I examine the relatively high rates of EGP's in the Australian magpie from a phylogenetic perspective. Although inbreeding avoidance is strongly supported by this study as the major reason EGP is so common in magpie populations, there may be an element of phylogenetic inertia that maintains the frequency of this behavioural trait. I comment upon the use of single-population estimates of species EGP rates in comparative analyses, given the intraspecific variation discovered between Australian magpie populations. Future directions for the study of mate choice in the Australian magpie are outlined with a proposal to study variation at the major histocompatibility complex between mated pairs.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Australian School of Environmental Studies
Full Text

The Australian magpie (Gymnorhina tibicen) is a large, sedentary, omnivorous passerine. In some populations, individuals live in groups, and some of these groups breed cooperatively. The white-backed magpie (G. t. tyrannica) from the south-eastern corner of the continent, has had relatively little study, and few details are known of its mating system, social structure, and method of parental care. I conducted an observational study on a population of white-backed magpies, recording details of their demography, dispersal, breeding system, and parental care. In conjunction, I conducted a genetic analysis of the population, to determine if the genetic mating system matched the observed social system, to detect instances of extra-group mating, and to sex juvenile birds. Extra-pair paternity (EPP) is a common feature of the mating systems of many birds. The rate of EPP may vary between species, races and populations. I made a comparison of extra-group paternity (EGP) rates between two races of the Australian magpie, to determine if similar mating systems were being employed. The two populations had similar social structure, but differed in group size and dispersal. I predicted that dispersal differences would have a profound effect on the rate of EGP between the populations, as the population with the lower rate of dispersal and higher chance of breeding with a close relative would engage in EGPs more frequently. Eight microsatellite loci were used to determine parentage in the white-backed Australian magpie. The rate of EGP was found to be 44%. Dispersal rates were estimated from observational data. Over half of the juvenile magpie cohort from the previous breeding season leave the territorial group. These results contrast sharply with the results found by other researchers in a population of western Australian magpies (G t. dorsalis). In this population, 82% EGP is recorded and dispersal of juveniles is close to nil. The results indicate that dispersal rate is a potentially important predictor of rates of extra-group fertilisations between populations of this species, and suggest that females maximise their reproductive output by avoiding breeding with close kin. The reproductive success of a male bird is often correlated with measurable traits that predict his intrinsic quality. Females are thought to select mates based on their quality to gain their 'good genes'. Male Australian magpies of the white-backed race were trapped in two breeding seasons. Measurements were taken of morphometric and other characteristics in order to discover whether particular traits of males were associated with: a) number of fledglings produced in the territory per season; b) percentage of offspring sired in the territory; and c) whether females select males for their 'good genes'. The only variable that was correlated with number of territorial offspring was feather lice load. Males with high numbers of lice were less likely to produce territorial fledglings in one season and across both seasons. Males of inferior quality may be subject to increased conspecific territorial intrusions, leading to more time spent on defence, more failed breeding attempts, less time allocated to grooming and thus high parasite loads. Males that produced many territorial fledglings were more likely to gain genetic paternity of at least some of them, although again this was significant for only one season. Also, across both seasons, a high number of females in the group was correlated with increased paternity within the group. The general lack of correlation between the variables and level of genetic paternity may be due to females engaging in extra-group mating primarily to avoid breeding with a close relative rather than to choose a quality male. In this scenario, males would not have to be 'high quality', but merely genetically different to the female's social mate. Extra-group paternity (EGP) can affect paternal effort. It may also influence the helping effort of auxiliary birds in cooperatively breeding species. If helping is driven by kin selection, helpers should decline to provision unrelated young. Relatedness becomes difficult to assess however, when females mate outside the group. Alternative rewards may then become important in helper decisions. In my study population of Australian magpies, 38% of fledglings were sired by males outside the territorial group. In a second population (G. t. dorsalis), 82% of fledglings were sired by extra-group males. I observed within-group male and helper feeding effort over three breeding seasons in the first population and obtained data recorded over a single season in the second population. In both populations, males provisioned young regardless of relatedness, as did helpers. Males provisioned less than the nesting female on average. Paternal effort did not reduce with an increase in the rate of EGP between populations. In the population with intermediate levels of EGP, the white-backed magpies, I observed helpers in about half of the sampled territories that produced fledglings. Helpers did not increase the production of young. In the population with high levels of EGP, western magpies, I detected helping behaviour in proportionally more territories. It appears that Australian magpie helpers provide help in order to pay 'rent' and remain on the natal territory. I discuss these results in light of the differences between the two races of magpie and the major theories regarding male parenting decisions and helper activity. Finally, I examine the relatively high rates of EGP's in the Australian magpie from a phylogenetic perspective. Although inbreeding avoidance is strongly supported by this study as the major reason EGP is so common in magpie populations, there may be an element of phylogenetic inertia that maintains the frequency of this behavioural trait. I comment upon the use of single-population estimates of species EGP rates in comparative analyses, given the intraspecific variation discovered between Australian magpie populations. Future directions for the study of mate choice in the Australian magpie are outlined with a proposal to study variation at the major histocompatibility complex between mated pairs.

This thesis reports on a study which developed a profile of the reviewers of children's books in Australia. It then compared the profile with one which was developed by Kathleen Craver in 1984 of children's book reviewers in the United States. Five research questions were addressed by this study relating to reviewers and their opinions regarding review aspects, reviewer roles and review practices within the framework of their personal and professional background. Craver surveyed the reviewers from School Library journal because as a group, they provided the greatest potential for statistical significance of all the reviewing journals in the United States. As no Australian journal enjoys either the number of reviewers or the circulation of School Library journal, reviewers from eight journals which are most used by teacher and children's librarians were selected to form the population for this research. These journals are Fiction Focus, LINES, Magpies, Reading Time, Reviewpoin t, Review Bulletin, Scan and Tasmanian Resources Review. The reviewer profile which emerged from this study was very similar to Craver's in that it was not one which could be entirely defined in terms of group characteristics. Selected cross tabulations either with the particular journals, demographic details, or other variables, particularly those relating to reviewer experience failed to produce predictable behaviourial correlations. However, reviewers were united on certain issues which can be attributed to their own professional background.

During the Pleistocene, fluctuating climates led to cycles of glacial/arid activity interspersed with pluvial periods across continents in both northern and southern hemispheres. Many studies in the northern hemisphere have used genetic analysis to document the important role that glacial activity has played in structuring avian populations at high latitudes. However, few have attempted to study the associated effect of aridification at low latitudes in the southern hemisphere. I investigated the past effects that cyclic aridification may have had on the population structure and history of a widespread endemic Australian bird species, the Australian magpie (Gymnorhina tibicen) and two species of obligate feather ectoparasites. 1166 samples from across the native range of G. tibicen were analysed for mitochondrial control region sequence variation and variation at six microsatellite loci. Analysis of mitochondrial control region sequence data indicated monophyletic clades that were geographically congruent with an eastern and western region. Analysis of mitochondrial variation at the sites sampled in this study suggested the contemporary distribution of eastern and western clades is non-overlapping but in close proximity. Analysis of microsatellite variation suggested that secondary contact may have occurred between eastern and western clades in north-western Australia. From AMOVA analysis and Bayesian analysis of population structure (BAPS) it was indicated that contemporary nuclear gene flow preceded mitochondrial gene flow from eastern populations through to north-western Australia. Most eastern, northern and north-western sites showed little geographic structure for microsatellite variation. BAPS analysis of microsatellite variation however, suggested there was as much structure among south-west populations as there was between eastern and western populations. For a majority of population comparisons, estimates of gene flow based on coalescent analyses (LAMARC) suggested higher gene flow rates for males than predicted by differences in effective population size of nuclear DNA compared to mitochondrial DNA. This result coupled with the spread of nuclear DNA preceding mitochondrial DNA supports earlier studies that suggest dispersal in magpies in male biased. Using the program IM, eastern and western mainland clades were estimated to have diverged in the Pleistocene around 36, 000 years ago. The island population of Tasmania was even more recent in origin, possibly since sea levels rose 16,000 years ago, inundating Bass Strait. The putative Carpentarian and possibly Canning barriers in the north and the Nullarbor-Eyrean arid barriers in the south appear to be associated with the divergence between eastern and western mainland populations. Nested clade analysis indicated a signature of range expansion in the eastern region suggesting movement possibly inland and northward subsequent to the last period of aridity. Although not significant, north-eastern and south-eastern populations appeared to show some evidence of a population expansion from mitochondrial DNA. Collectively, phylogeographic analyses suggested that increasing aridity during the Pleistocene played an important role in structuring the Australian magpie. The east to west pattern of mtDNA divergence that was identified contrasts with the striking north to south pattern in morphological (back colour) variation in magpies. Over a large proportion of northern Australia, magpies are black backed (BB) and over a smaller area in southern Australia, magpies are white backed (WB). Between BB’s and WB’s a contact zone is present where both parental forms and magpies with an intermediate black band occur. The discordance between back colour and mtDNA structure in magpies suggests recent history is not responsible for the morphological variation. Mitochondrial cytochrome oxidase I sequence variation was analysed for two species of feather lice associated with G. tibicen. Philopterus sp. has greater habitat specificity than Brueelia semiannulata and as predicted showed deeper divergences among populations than B. semiannulata. There was concordance between the distribution of mitochondrial clades for Philopterus sp. and magpies. The overlap of eastern magpie haplotypes and western Philopterus sp. haplotypes at one site suggested secondary contact among eastern and western clades in northern Australia. Two clades were also evident for B. semiannulata. However they were not congruent with geographic structure of the host or Philopterus sp. Rather, the two non-overlapping B. semiannulata clades were distributed in northern and southern Australia. The divergent clades of B. semiannulata may represent populations that diverged on magpies that were isolated prior to the last period of aridity. It was evident that gene flow occurs among populations of northern and southern B. semiannulata; therefore the contemporary maintenance of divergent clades may be due to selection. One possibility is that selection for thermal tolerance is maintaining current distributions of B. semiannulata.Overall microsatellite variation and mtDNA variation in host and lice suggest that increasing aridity and Pleistocene refugia played a role in structuring populations of the Australian magpie. Since the Pleistocene, the dispersal ability and generalist habitat requirements may have facilitated the movement of magpies into an almost contiguous modern distribution across the continent. This study supports the idea that Pleistocene aridification played an important role in structuring intraspecific variation in low latitudinal southern hemisphere avian species.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Australian School of Environmental Studies
Faculty of Environmental Studies
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The Australian magpie is one of our nation’s most popular and iconic birds. It is loved for its impressive vocal abilities, propensity to play, excellent parenting and willingness to form enduring friendships with people. Written by award-winning author Gisela Kaplan, a leading authority on animal behaviour and Australian birds, this second edition of Australian Magpie is a thoroughly updated and substantially expanded account of the behaviour of these birds. With new chapters on classification, cognition and caring for young, it reveals the extraordinary capabilities of the magpie, including its complex social behaviour. The author, who has devoted more than 20 years to studying and interacting with magpies, brings together the latest research on the magpie’s biology and behaviour, along with information on the origin of magpies, their development and health not published previously. This fascinating book has a wide appeal to bird lovers, amateur ornithologists and naturalists, as well as those with a scientific or professional interest in avian behaviour and ecology and those interested in the importance of native birds to the environment.

The warbling and carolling of the Australian magpie are familiar to many although few of us recognise that it ranks among the foremost songbirds of the world. Its impressive vocal abilities, its propensity to play and clown, and its willingness to interact with people, make the magpie one of our most well-known birds. This insightful book presents a comprehensive account of the behaviour of one of Australia's best-loved icons. It reveals the extraordinary capabilities of the magpie, including its complex social behaviour, in a highly readable text. The author brings together much of what we know about the magpie’s biology and behaviour, including her latest research on magpie vocalisation as well as aspects of anatomy, physiology, development and health not published previously. Australian Magpie is ideal reading for all those interested in Australian natural history, including amateur and professional ornithologists, and undergraduate students.

Abstract This chapter describes the common terminologies, taxonomy, morphology, geographical distribution, physiology, diet, behaviour, reproduction, habitats, ecology, invasion pathways, environmental impact, control and human use of the Australian magpie (Gymnorhina tibicen).