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1
Gustafson, Tomas Berg Åke. "Bird communities and vegetation on Swedish wet meadows : importance of management regimes and landscape composition /". Uppsala : Swedish University of Agricultural Sciences, 2006. http://diss-epsilon.slu.se/archive/00001234/.
Testo completoAbstract (sommario):
Thesis (doctoral)--Swedish University of Agricultural Sciences, 2006.Errata sheet inserted. Appendix includes reproductions of papers and manuscripts co-authored with Åke Berg. Includes bibliographical references. Issued also electronically via World Wide Web in PDF format; online version lacks appendix of papers.
2
Alizadeh, Shabani Afshin, e afshin alizadeh@rmit edu au. "Identifying bird species as biodiversity indicators for terrestrial ecosystem management". RMIT University. Mathematical and Geospatial Sciences, 2006. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20061116.161912.
Testo completoAbstract (sommario):
It is widely known that the world is losing biodiversity and primarily it is thought to be caused by anthropogenic activities. Many of these activities have been identified. However, we still lack a clear understanding of the causal relationships between human activities and the pressures they place on the environment and biodiversity. We need to know how ecosystems and individual species respond to changes in human activities and therefore how best to moderate our actions and reduce the rate of loss of biodiversity. One of the ways to detect these changes is to use indicators of ecosystem conditions. Indicators are statistics following changes in a particular factor usually over time. These indicators are used to summarise a complex set of data, and are seen as being representative of the wider situation in that field. So it can be assumed that if that particular factor is declining or improving, then the situation in general is also declining or improving. They are used to check the status and trends of biodiversity by both the public and policy makers. Indicators are also used to assess national performance and can be used to identify the actions required at the policy level. In this manner, they provide an important link between policy-makers and scientists collecting the data. The current thesis investigates the possibility of using bird species as indicators of biodiversity for better management of natural terrestrial ecosystems, by identifying their habitats according to various environmental factors. The study is established by drawing upon three main scientific areas: ecology, geographical information system (GIS), and statistical modelling. The Mornington Peninsula and Western Port Biosphere Reserve (MPWPBR) (Victoria, Australia) was chosen for the study area because of the combination of suburban and natural environments that made it optimum for this type of study. Once the study area was defined, the necessary data for the research were obtained from various sources. Birds Australia provided data on recorded observation of 271 bird species within the study area. Based on the nature of this study, seven species were selected for the study. The criteria for this selection are discussed in Chapter 3. Most literature state that the primary determinant for bird abundance is vegetation and land cover. Because of this, Ecological Vegetation Class (EVC) layer was used to determine which type(s) of vegetation have the greatest impact on habitat selection. Each species showed a relationship to a number of v vegetation types. These EVCs were combined to produce vegetation patches, and were considered as potentially suitable habitats of corresponding bird species. For each of the species, these habitat patches were analysed for the different aspects of patch characteristics (such as the level of patchiness, connectivity, size, shape, weighted distance between patches, etc.) by using the Landscape Context Tool (a GIS add-on). This process assisted the understanding of the importance of patch quality in habitat selection among different bird species by analysing the location of bird observation sites relative to habitat patches. In this way, the association between bird presence and the conditions of a habitat patch was identified by performing a discriminant function analysis. To investigate the probability of a species presence according to different environmental factors, a model of species distribution was created. Binary logistic regression was used to indicate the level of effect of each variable. The model was then successfully validated in the field. To define the indicators of environmental factors, it was essential to separate bird species based on their dependency on one or more of the studied variables. For this purpose, One-Way ANOVA was used. This analysis showed that some bird species can be considered as indicators of urban areas, while others could be good indicators of wellpreserved large forests. Finally, it must be mentioned that the type and quality of the datasets are crucial to this type of study, because some species have a higher degree of sensitivity to certain types of vegetation or land cover. Therefore, the vegetation data must be produced as detailed as possible. At the same time, the species data needs to be collected based on the presence and absence (versus presence-only) of the birds.
3
Pepper, Margaret A. "Salt marsh bird community responses to open marsh water management". Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 61 p, 2008. http://proquest.umi.com/pqdweb?did=1597631021&sid=5&Fmt=2&clientId=8331&RQT=309&VName=PQD.
Testo completo
4
Godinho, Carlos António Marques Pereira. "The influence of forest management on bird communities of portuguese montados". Doctoral thesis, Universidade de Évora, 2016. http://hdl.handle.net/10174/20680.
Testo completoAbstract (sommario):
The world distribution of cork oak Quercus suber and holm oak Q. rotundifolia
is basically restricted to the western Mediterranean basin. These two evergreen oaks
are the base of the Portuguese montado and the Spanish dehesa.
This thesis aims to analyse how bird communities of the montado are influenced
by management practices. We used different approaches to study this relationship,
and to evaluate which features are responsible for species distribution in different
typologies of montado. First, we reviewed the concept of montado in order to better
understand the system and to set thresholds on what can be considered as montado.
Afterwards, we studied the elements that promote higher species diversity and
individual species, or group of species, that can act as indicators of High Nature Value
for montados. Finally, we evaluated how the bird communities are structured, and the
influence of the main management actions (e.g. cattle and cork exploitation) on those
communities; Resumo:
A distribuição mundial do sobreiro Quercus suber e da azinheira Quercus
rotundifolia é praticamente restrita à bacia do Mediterrâneo. Estas duas espécies de
carvalhos são a base dos montados em Portugal e das dehesas em Espanha.
No âmbito desta tese analisamos como as comunidades de aves do montado
são influenciadas pela gestão florestal. Para este efeito usámos diferentes
abordagens e avaliámos quais as características do montado responsáveis pela
distribuição das espécies ao longo das suas diferentes tipologias.
Fizemos uma revisão do conceito de montado e proposemos uma definição
para o sistema, englobando a sua multifuncionalidade. Estudámos os elementos
singulares que promovem a diversidade de aves e que podem ser simultaneamente
indicadores de áreas de Alto Valor Natural (HNV). Por fim, avaliámos qual a influência
da gestão (p. ex. pastoreio e descortiçamento) na estruturação das comunidades de
aves.
5
Stowe, T. J. "The habitat requirements of some insectivorous birds the management of sessile oakwoods". Thesis, University of Cambridge, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377582.
Testo completo
6
St, John Barbara J. "Ecology and management of the Little Corella (cacatua sanguinea) in the southern Flinders Ranges, South Australia /". Title page, contents and abstract only, 1994. http://web4.library.adelaide.edu.au/theses/09SM/09sms143.pdf.
Testo completo
7
Salminen, Mandy M. "Breeding Bird and Bat Activity Surveys at Dairymen's Inc". Wright State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=wright1507213426130855.
Testo completo
8
Gustafson, Tomas. "Bird communities and vegetation on Swedish wet meadows : importance of management regimes and landscape composition /". Uppsala : Swedish University of Agricultural Sciences, 2006. http://diss-epsilon.slu.se/archive/00001234/.
Testo completoAbstract (sommario):
Thesis (doctoral)--Swedish University of Agricultural Sciences, 2006.Title from PDF file as viewed on 11/28/2006. Includes bibliographical references. Also available in print. Print version includes appendices.
9
Lipschutz, Maia Lynn. "Effects of drought and grazing on land bird populations in South Texas". Thesis, Texas A&M University - Kingsville, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10129021.
Testo completoAbstract (sommario):
Breeding bird surveys were conducted on 7 properties belonging to 2 ranches in South Texas. Using these data I calculated temporal trends, and tested the effects of total May–April precipitation and cattle stocking rate on avian abundance. Trends were calculated for each ranch, the East Foundation and King Ranch, individually due to different range and wildlife management practices. Total avian abundance increased significantly on the 3 East Foundation properties between 2008 and 2015. During 39 breeding bird surveys, 16,441 individual birds of 88 species were recorded. Non-breeding bird surveys were also conducted on East Foundation properties, an increasing trend in total avian abundance was also calculated from these data. Total breeding bird abundance was stable on the 4 King Ranch properties between 2005 and 2013. A total of 19,162 individual birds of 87 species were recorded during 40 breeding bird surveys. The combined effect of livestock use and precipitation had a significant effect on total avian abundance on all King Ranch properties, and on the abundance of some individual species and groups.
10
Kirkpatrick, Christopher Kreitler. "Trends in grassland bird abundance following prescribed burning in southern Arizona". Thesis, The University of Arizona, 1999. http://hdl.handle.net/10150/278702.
Testo completoAbstract (sommario):
I examined trends in relative abundance and species richness of breeding and wintering grassland birds before (1996) and after (1997, 1998) a spring prescribed burn in a mesquite-dominated desert grassland at Buenos Aires National Wildlife Refuge, Arizona. The burn was moderate in intensity, patchy in extent, and affected ground cover more strongly than shrub cover, smaller shrubs more strongly than larger shrubs, and killed 1% of velvet mesquite (Prosopis velutina). Species richness of breeding birds decreased in the first year post-burn. Of breeding species, black-throated sparrows (Amphispiza bilineata) and mourning doves (Zenaida macroura) increased; whereas Botteri's sparrows (Aimophila botterii), Cassin's sparrows (Aimophila cassinii), and pyrrhuloxias (Cardinalus sinuatus) decreased in relative abundance. Breeding species characterized as not shrub-dependent exhibited changes that were more pronounced than those for shrub-dependent species. Of wintering birds, ladder-backed woodpeckers (Picoides scalaris) and vesper sparrows (Pooecetes gramineus) increased, and cactus wrens (Campylorhynchus brunneicapillus) decreased in relative abundance.
11
Downing, Beatrice Catherine. "Disruption and disease : how does population management affect disease risk in wild bird populations?" Thesis, University of Exeter, 2017. http://hdl.handle.net/10871/29259.
Testo completoAbstract (sommario):
Despite the ubiquity of wildlife management, from reintroductions and supplemental feeding to culling and habitat destruction, very little is known of the effects of management practices on species’ social dynamics. Species’ social structure has the potential to affect not only behaviour and evolution but also the transmission of information or disease. Understanding the effects of population management on social behaviour and organisation is a key step in understanding these species’ ecology. This thesis examines the differences between individuals’ roles in the social structure and what this means for the transmission of disease. It demonstrates how similarity in movement behaviour scales with increasing social circles, how seasonality in movement and seasonality in association rates covary as well as detailing post-cull behavioural changes. It finds that there is the potential for certain individuals (most likely non-breeding individuals) to transmit infection far and wide. It reveals the similarities in movement behaviour and body condition that birds share with their pair and social group. It emphasises the importance of autumn and winter movement in the transmission of infectious disease and it follows the short- and long-term changes in social structure and movement behaviour following a cull. Cull survivors were observed to retain a higher proportion of associations with their previous associates and moved less far in the year following the cull than in the year preceding it. This is the first application of social network analysis to quantify social structure before and after culling. The findings suggest that culling an infected population may facilitate rather than constrain the transmission of disease.
12
Brito-Aguilar, Rafael. "Effects of even-aged forest management on early successional bird species in Missouri Ozark forest". Diss., Columbia, Mo. : University of Missouri-Columbia, 2005. http://hdl.handle.net/10355/4239.
Testo completoAbstract (sommario):
Thesis (M.S.)--University of Missouri-Columbia, 2005.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (May 26, 2006) Includes bibliographical references.
13
Tubelis, Dárius Pukenis. "Patch-matrix interactions and bird species conservation in a plantation-dominated landscape in Australia". Connect to this title online, 2005. http://tede.ibict.br/tde_busca/arquivo.php?codArquivo=327.
Testo completo
14
Pereira, Pedro Miguel Filipe. "How important is the availability of food resources for breeding birds at montados ? Exploring bird-arthropods relationships on a Mediterranean landscape". Master's thesis, Universidade de Évora, 2010. http://hdl.handle.net/10174/21076.
Testo completoAbstract (sommario):
As práticas de gestão dos sistemas de carvalhos mediterrânicos podem aumentar a sua susceptibilidade a pragas de insectos. As aves insectivoras são dominantes entre a comunidade nidificante desses habitats. Neste sentido, em montados de sobreiro Quercus suber do Centro de Portugal procurámos determinar a importância dos artrópodes para as aves nidificantes e identificar quais as relações entre as aves e as pragas (desfolhadores e cobrilhas). Utilizámos partição de variância para determinar a importância de três grupos de variáveis para as aves: comunidade de artrópodes, características da vegetação e práticas de gestão. Os artrópodes apresentaram o maior efeito puro com 11,24% de variância explicada, de um total de 61,20%. As aves relacionaram-se directamente com estes pela associação a presas potenciais ou indirectamente, nomeadamente pela selecção do habitat de nidificação. Seguidamente as pragas foram modeladas em função das variáveis ornitológicas através de regressões lineares. Os coeficientes de regressão indicaram que o chapim-real Parus major, conjuntamente ou não com outras aves da folhagem, e a trepadeira Certhia brachydactyla foram potenciais predadores dos insectos desfolhadores. Por outro lado, o pica-pau-galego Dendrocopos minor aparentou ser indicador dos ataques das cobrilhas. Consequentemente, a conservação das aves nidificantes em cavidades pode contribuir para a conservação do montado. - ABSTRACT: The management practices of Mediterranean oak systems can enhance their susceptibility to insect outbreak. At these habitats, the insectivorous bird species are dominant within the breeding community. Accordingly, we aimed to assess the importance of arthropod community for breeding birds and identify which species may be related with insect outbreak (defoliator and buprestid beetles) at central Portugal in montado systems dominated by Cork Oaks Quercus suber. We used variance partition to determine the relevance of three environmental variable groups for birds: arthropod community, vegetation characteristics and management practices. As a result, arthropods presented the highest pure effect with 11.24% of variance explained from a total of 61.20%. Bird-arthropod relationships were direct when associated with a potential-prey or indirect mostly when dependent on a breeding site selection. Thereafter, linear regression was used for pest insect modeling in function of bird community parameters. The obtained regression coeficients indicated that Great Tit Parus major, alone or with other foliage-dwelling birds, and Short-toed Treecreeper Certhia brachydactyla were potential predators of defoliator insects. Whereas the Lesser Spotted Woodpecker Dendrocopos minor appeared to be an indicator of Buprestid outbreak. Consequently, the protection of hole -nesting birds can improve the conservation of oak habitats.
15
White, Hillary M. "Riparian Bird-Habitat Association Models: A Framework for Informing Management and Developing Restoration Guidelines in Utah". DigitalCommons@USU, 2011. https://digitalcommons.usu.edu/etd/910.
Testo completoAbstract (sommario):
Approximately 75% of the avian species in Utah use riparian habitats at some time during their life cycles and at least 80% of this habitat in Utah has been lost or altered since settlement; currently 0.6% of land cover in Utah is considered riparian. In 1992, with the support of Utah Partner's in Flight, the Utah Division of Wildlife Resources began a statewide neotropical migratory bird (NTMB) and habitat monitoring program to assess the status of bird populations at 31 sites. Additional sites (up to 52) were added in later years; bird and habitat assessments at 37 riparian sites have been continuously monitored since 1998. Using this long-term dataset, my primary study goals were to: 1) estimate abundance and densities of 38 focal avian species, 2) document and describe changes in riparian vegetation over time, and 3) investigate how these two processes are related by creating bird-habitat association models. Recent results from population trend analyses suggest that the patterns of annual variation and regional synchrony seen in riparian-dependent species groupings may be driven by landscape-wide effects on habitat. I developed riparian-bird habitat association models to better understand these large-scale effects using important variables specific to nine species of interest. I constructed classification and regression trees for three distinct foraging guilds to assess species-specific and community level habitat associations. Variables identified as important predictors of species density varied according to the species of interset. However, the variables selected by the classification models were consistent with each species life history strategies. Model results are intended to provide the framework for the development of management guidelines that will inform terrestrial riparian restoration and conservation efforts in Utah.
16
Porter, Rosalyn. "Mathematical models of a tick borne disease in a British game bird with potential management strategies". Thesis, University of Stirling, 2011. http://hdl.handle.net/1893/3039.
Testo completoAbstract (sommario):
Louping ill virus (LIV) is a tick borne disease that causes mortality in red grouse, an economically important game bird of British uplands. The aim of this thesis is to extend previously published models of LIV , to consider the potential impact of different management strategies. In addition a new route of infection and the seasonal biology of both grouse and ticks will be explored. Grouse chicks are known to eat ticks as part of their diet in the first three weeks of life which may contribute to virus persistence if chicks consume infected ticks. This novel route of infection is incorporated in to the model which predicts that ingestion increases the range of host densities for which the virus is able to persist. The ingestion of ticks by grouse also reduces the tick population so that for low host densities the ingestion of ticks by grouse reduces the tick population so virus cannot persist. The model is adapted to take account of the seasonal biology of grouse and ticks. Although the temporal predictions of the seasonal models show some differences the addition of seasonality does not alter the model predictions of when LIV is likely to persist at different grouse and deer densities. Consequently seasonality is felt to be unimportant when considering management strategies. The treatment of sheep with acaricide in an attempt to reduce the tick population on a grouse moor is currently being trialled in Scotland. We use a model to predict the likely effect of this strategy at different deer densities. The number of ticks found attached to sheep varies so we consider the effect of tick attachment rates as well as acaricide efficacy. Although we predict that acaricide treated sheep can reduce the tick population and therefore LIV in grouse in some circumstances the treatment is less effective in the presence of deer. Consequently we use a model to make theoretical predictions of the effectiveness of acaricide treated deer as a control strategy for reducing LIV in red grouse. The effect of culling deer on LIV in grouse is also modelled and contrasted with the effect of acaricide use. It is predicted that acaricide treatment of deer could be highly effective, particularly if the deer density is first reduced by culling. Finally we considered the direct treatment of red grouse with acaricide. Female grouse can be given an acaricidal leg band which protects her directly and indirectly protects her chicks as they acquire some acaricide whilst brooding. Trials have suggested this can reduce tick burdens for individuals. We use the model to determine the potential effect that treating individual broods may have on the whole grouse population. The model predictions suggest that unless acaricide efficacy on chicks is high and long lasting treating individual broods is unlikely to reduce LIV in the whole population but will still provide some benefit for the individuals. The effectiveness of treatment is reduced by higher deer densities. The success of the management strategies considered in this thesis appear to be restricted by the presence of deer. It may therefore be that a combination of treatments including the treatment of deer may be of the greatest benefit to the grouse population.
17
Glithero, Neryssa J. "The Impact of Changing Landscape Management on Bird and Weed Populations; Scaling from Field to Landscape". Thesis, University of Reading, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.511677.
Testo completo
18
McClellan, Rachel Katherine, e n/a. "The ecology and management of Southland's black-billed gulls". University of Otago. Department of Zoology, 2009. http://adt.otago.ac.nz./public/adt-NZDU20090827.110233.
Testo completoAbstract (sommario):
The black-billed gull (Larus bulleri) is a small gull that nests in dense colonies on gravel-bedded rivers in southern New Zealand. This dissertation describes research undertaken in Southland in 2004-2006 that investigates black-billed gull population decline and its causes.
Historical ground counts of nests were calibrated with aerial photography of colonies and population trends analysed. The decline in breeding birds on Southland's four main rivers was equivalent to 6.0%/year (SE 1.8) or 83.6% in 30 years justifying the species' present listing as Endangered. Aerial monitoring is a poor index of the breeding population and major temporal variation was identified in counts.
All re-sighted second-year birds exhibited natal dispersal and -70% left the natal catchment. Forty one percent of birds banded as adults also dispersed to other catchments. Breeding dispersal is apparently unrelated to previous breeding success and the availability of the previous year's colony site, and dispersing birds did not move as groups. Southland's black-billed gulls constitute a single inter-mixing population.
Black-billed gulls selected sites on islands and banks according to availability, and selected rivers consistent with the number of gravel patches. Site vulnerability to floods varied significantly. Re-use of colony sites was positively influenced by use in previous years, the extraction of gravel, site stability and low weed cover. Widespread introduced weeds on colony sites preventing nesting and may have increased flooding risk. Colony size was related to colony area, which was related to gravel patch size.
Investigation of historical changes in breeding habitat availability in Southland indicated a major reduction in gravel habitat on the Lower Oreti River between 1976 and 2002 due to river works including gravel extraction. On the Waiau River, Manapouri Dam construction in 1970 initially increased gravel areas, since reversed in the mid Waiau, and caused a 75% decline in the number of islands. Gravel patch sizes are still declining on the Lower Oreti and possibly the Mid Waiau. Hundreds of gravel patches remain on Southland rivers.
Over 5000 nests in 21 colonies were monitored during incubation. Colony nest success was most influenced by colony location, averaging 90.1% (SE 2.1) on islands within rivers, and 66.8% (SE 2.2) on riverbanks, indicating that terrestrial predators exert the greatest influence on productivity. Breeding success, the mean number of fledglings produced per nest by colony, varied between 0 and 0.88 fledglings (mean 0.32, SE 0.08). Both parameters were positively related to colony size. The three smallest colonies failed to breed successfully, suggesting the presence of an Allee effect.
Deterministic matrix models were used to investigate population trends using survival and productivity estimates for the closely related Kaikoura red-billed gull (L. novaehollandiae scopulinus). Adult survival, followed by breeding success and survival of first year birds, had the greatest influence on population projections. Improvements in most parameters are probably required to reverse the decline of Southland's black-billed gulls.
Predation and disturbance by introduced mammals and the native black-backed gull (L. dominicanus) had the greatest impact on black-billed gull productivity. Most human disturbance is insignificant compared to predator disturbance, but illegal shooting of large numbers of adult gulls has major impacts in smaller sub-populations. Damming and excessive water abstraction reduces island habitat due to lowering of flows. Major climatic events such as droughts, and chemical ingestion through a diet dominated by agricultural invertebrates, are potential major threats about which little is known. Management actions including the collation and analysis of all unpublished black-billed gull count datasets, a thorough test of the accuracy of aerial monitoring, trialling of decoys to attract colonies to nest on islands, predator control at bank colonies, targeted weed control on high quality sites, advocacy and education and further research are recommended.
19
Thomson, Belinda. "A cost effective grassland management strategy to reduce the number of bird strikes at the Brisbane airport". Queensland University of Technology, 2007. http://eprints.qut.edu.au/16576/.
Testo completoAbstract (sommario):
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.
20
Johnson, Tracey N. "Ecological restoration of tallgrass prairie: grazing management benefits plant and bird communities in upland and riparian habitats". Thesis, Manhattan, Kan. : Kansas State University, 2006. http://hdl.handle.net/2097/190.
Testo completo
21
Dunn, Jenny Claire. "Farming and foraging : indirect effects of management on bird biology through changing distributions of food and predators". Thesis, University of Leeds, 2009. http://etheses.whiterose.ac.uk/15218/.
Testo completoAbstract (sommario):
Farmland songbirds have shown dramatic population declines that have been linked to agricultural intensification. Populations have been impacted via three key factors: a reduction in available nesting habitat, a reduction in the availability of food for nestlings, and a reduction in over-winter food availability. The abundance of nest predators such as corvids, and the presence of sub-clinical disease may also play a part, and this thesis investigates the inter-relationships of some of these five factors along with their potential impacts upon farmland bird populations, using the yellowhammer Emberiza citrinella as a model species. It appears that the quality, not the quantity of fledglings has declined, possibly due to delayed life-history effects following on from conditions experienced in the nest. Increases in corvid abundance are associated with declines in chick growth and condition, mediated by behavioural compensation by provisioning adults: these effects are especially marked in large broods and where invertebrate food supply is low; where food supply is high a slightly positive effect of corvid abundance on condition and growth is found, implying an adaptive response by adults to maximise food provisioning in order for chicks to fledge more quickly and thus reduce their risk of predation in the nest. High territory densities, found where the availability of suitable nesting habitat is high, are associated with apparent density-dependent competition for high quality food and reduced chick growth, probably reducing fledgling quality and potentially leading to population sinks in areas of good nesting habitat, or in areas with high corvid densities. Survival analysis from a yellow hammer population sampled over four successive winters indicates that survival is male-biased, probably due to the higher work rates of females during breeding. Survival probability increases with increasing wing length, although analysis of 21 years of ringing data from the same site indicate a significant trend towards decreasing wing length, when controlling for the effects of age and sex. This apparent paradox is likely to have arisen from a decline in wing length of fledglings recruiting into the population as a result of a decline in habitat quality or food availability, both of which have been shown to influence feather growth. Infection by blood parasites showed associations with reduced feather growth and may indirectly influence survival, possibly by compounding food stress over-winter.
22
Watkins, Nigel G. "Ecological correlates of bird damage in a Canterbury vineyard". Lincoln University, 1999. http://hdl.handle.net/10182/508.
Testo completoAbstract (sommario):
Birds are a major pest in vineyards both in New Zealand and overseas. There is a need for new behavioural research on birds' foraging habits and feeding preferences in vineyards, as much of the literature to date is anecdotal. Research on cues to birds' feeding will provide a basis on which new deterrent and control strategies can be devised. Spatial-and temporal bird damage in a small vineyard block was mapped to find if damage was correlated with grape maturity and environmental factors. Vineyard and field observations of bird behaviour using video technology combined with preference experiments aimed to establish the relative roles of grape sugar concentration and colour in avian selection. Proximity of vineyards to bird roosts affects damage levels, regardless of differing maturity between locations. The rate of damage tends to increase exponentially once grape maturity has passed a threshold of 13 °Brix. Bunches positioned closest to the ground receive more damage if blackbirds or song thrushes are the predominant pests. Both sugar concentration and grape colour were found to affect birds' feeding preference, but the importance of the two factors varied between years. Black and green grape varieties were differentially preferred by blackbirds (Turdus merula) and song thrushes (Turdus philomelos) while silvereyes (Zosterops lateralis) appeared to have no strong colour preference. It was apparent that there were other, not assessed, grape factors that also affect selection. In small unprotected vineyards that are adjacent to bird roosts the entire grape crop can be taken by bird pests. Besides removing the roosts, which can be beneficial shelterbelts in regions exposed to high winds, growers currently may have no alternative other than to use exclusion netting to keep crops intact. The differential preferences between bird species for variety characteristics suggest that any new deterrents and other strategies to deflect birds from grape crops may need to be species-specific.
23
Correia, Ricardo. "Effects of climate and land management changes on conservation : of mediterranean cork oak woodlands and their bird communities". Thesis, University of East Anglia, 2014. https://ueaeprints.uea.ac.uk/50549/.
Testo completoAbstract (sommario):
Cork oak woodlands are a keystone habitat for Mediterranean biodiversity but are currently undergoing a global decline and widespread management changes driven by social, economic and climatic factors. I examine the effects of both climate and land management changes on cork oak woodlands and their bird communities across the western Mediterranean Basin. Future climatic scenarios indicate that up to 60% of current cork oak woodlands may become unsuitable by 2080, especially in southern areas where they will be restricted to microclimatic refugia sites. Increasing aridity, particularly in drier microclimates, will potentiate a decline of cork oak tree condition resulting in impacts across the food web that ultimately have a negative effect on breeding bird abundance and diversity, particularly for tree-dependent forest species. Farmland and shrubland birds respond mainly to habitat features modified by land management and their abundances increase in areas with open and heterogeneous ground cover. Current abandonment, intensification and overexploitation trends are likely to have negative effects on their populations but climate change can also play an important role if it provides an additional stimulus for land management changes. The unique bird assemblages of North African cork oak woodlands seem particularly vulnerable to both factors and should therefore be considered a conservation priority. Nonetheless, climate change may benefit species of Mediterranean origin and seems to have enabled the establishment of resident populations of traditionally migratory bird species in the Iberian Peninsula. This may provide new conservation opportunities for declining migratory species as long as adequate winter habitat areas are available. Adaptation strategies should aim to incorporate biodiversity-friendly management practices, promote cork oak afforestation in areas that will become climatically suitable and evaluate alternatives to provide similar economic and environmental services in the regions where cork oak woodlands are likely to disappear.
24
Shew, Justin J. "EFFECTS OF SCALE AND HABITAT MANAGEMENT ON GRASSLAND BIRD RESPONSE IN CONSERVATION RESERVE PROGRAM FIELDS IN NORTHWEST ILLINOIS". OpenSIUC, 2016. https://opensiuc.lib.siu.edu/dissertations/1323.
Testo completoAbstract (sommario):
North American populations of grassland birds have been declining consistently for the past several decades. Grassland birds respond to multiple scales which encompass a spectrum of habitat variables, and the habitat scale of importance may depend on the response of interest. For practitioners, having knowledge of the effect of scale is useful because conservation efforts can be focused at the most appropriate scale. However, previous multi-scale studies of grassland birds and other taxa have rarely incorporated on-the-ground habitat management while simultaneously investigating site-specific species turnover dynamics (Chapter 1) and daily nest survival (Chapter 2). Also, habitat management-related studies often suffer when not accounting for inherent variation between fields, field landscapes, and study year; thus, to disentangle specific effects of management, it is important to account for this variation by using these factors as random effects within mixed-effects models (Chapter 3). Understanding multi-scale habitat relationships affecting site turnover, also known as dynamic occupancy, and daily nest survival rate (nest survival or DSR), as well as how multiple avian responses vary with grassland management would further benefit conservation decision making for focal species. I investigated dynamic occupancy and nest survival of both obligate and facultative grassland species relative to multi-scale habitat factors on private lands (Conservation Reserve Program) in northwest Illinois during 2011-2014. I also conducted a separate analysis focusing on how multiple avian responses, ranging from species presence/absence (P/A) to species-specific nest survival, are influenced by non-fire grassland management treatments. For dynamic occupancy, a combination of ≥2 scales always outperformed single-scale models for all species. Three of 7 species responded to either cumulative habitat management (proportion of field managed over the study period) or yearly management (33% of field managed before a particular breeding season) regardless of dominant grass type. Of the 48 covariates appearing in top models across species for both dynamic and single-season occupancy, microhabitat covariates (42%) were represented most often, followed by patch-scale (33%) and landscape-scale (25%) factors. Covariates with the most consistent effects and the greatest frequencies appearing in competitive (∆AIC ≤ 4) dynamic and single-season occupancy models included landscape forest cover (n = 10), surrounding patch grassland cover (n = 7), and field size (n = 6). In general, increasing levels of forest cover adjoining fields had consistently negative effects on occupancy, colonization, and persistence across species, while grassland surrounding fields and field size had positive effects on these responses. Microhabitat covariates better explained colonization and extinction across the focal species. Of the 22 habitat covariates in top colonization and extinction models, microhabitat variables were represented 50% of the time, compared to 32% and 18% representation for patch-scale and landscape-scale covariates, respectively. I recommend that wildlife biologists utilize habitat management techniques to ensure grassland birds have different successional stages within their range of preferences. My results suggest that grassland disturbance, while influencing turnover dynamics of different species, may be less influential within smaller fields and landscapes dominated by forest cover. I analyzed the daily nest survival rate for 2 species (red-winged blackbirds and dickcissels) and 2 groups of nesting communities (ground and above-ground nesters). Temporal variables such as Julian date and stage of nest were significant predictors of nest survival for red-wings (50.58 ∆AICc = best temporal model) and dickcissels (2.28 ∆AICc = best temporal model) in addition to habitat covariates. In 3 of 4 analyses ≥2 habitat scales were better predictors of nest survival over one scale. For ground nesters the patch scale was be best predictor of nest survival. However, the best model for ground nesters did not have overwhelming support compared to the random model (1.43 ∆AICc). The ground-nesting community appeared to suffer decreased nest survival with increasing proportion of surrounding grassland. The blackbird top model included nest- and landscape-scale covariates, and top models for dickcissels and the above-ground nesting community included the nest- and patch-scale covariates. Blackbirds had a significant increase in nest survival when nests were placed in areas with higher vegetation density and height (greater visual obstruction). Comparatively, the predictive ability of habitat covariates was not as strong for the other 3 analyses; however, notable patterns include dickcissel nest survival decreasing with increasing nest distance to edge and above-ground nests had increased nest survival with increasing patch perimeter-area-ratio. My results suggest different species are responding to different scales, but finer-scale habitat covariates generally help predict nest survival over course-scale habitat features, such as landscape covariates. Songbird nest survival maybe more influenced by fine-scale habitat characteristics such as nesting cover and field vegetation complexity and density, which can deter nest predators and reduce their search efficiency. In a way, this is positive news for practitioners working in grasslands patches located in less than ideal patch or landscape configurations, suggesting more effort could be focused on improving conditions for colonization and persistence of focal species (Chapter 1). By focusing management on dynamic occupancy responses, increasing potential nesting habitat and territory quality for focal species will likely follow. When investigating multiple avian responses to management, within a consistent mixed-effect modeling framework, it appeared that avian survey related responses were best supported, having consistently larger ∆AICc values for top models, when compared to nesting-related data. One explanation of this relative difference could be attributed sample size difference between analyses. Focusing on the effects of management, this analysis accounted for inherent variation across fields, year, and potentially field landscape, as random effects within all models. As suggested from Chapter 2, and despite a large sample of nests, explanation of DSR across all species and focal species showed little improvement with management covariates. Brome fields cumulatively managed with spray or spray/seed treatments (Chapter 1) appeared to respond most and likely explained general positive effects for red-winged blackbird and dickcissel abundance; however, this was at a cost to species abundance for bobolink (Dolichonyx oryzivorus), Henslow’s sparrow (Ammodramus henslowii), eastern meadowlark (Sturnella magna), field sparrow (Spizella pusilla), and northern bobwhites (Colinus virginianus), due to the release of tall forbs within the seed bank after spraying brome dominated fields. Dramatic vegetation responses in sprayed brome fields likely led to an overall decrease in obligate-grassland bird richness and conservation value on brome field types that were cumulatively management over the course of the study. These results suggest the importance of non-native brome CRP fields for certain grassland-obligate bird species, while also revealing the apparent decoupling of nest survival and other avian responses measured commonly. I suggest managers and researchers pay closer attention to variables affecting nesting abundance/density in grassland systems when possible and recognize the potential importance of non-native grasses for grassland-obligate birds in some regions.
25
Correia, Ricardo. "Effects of climate and land management changes on conservation : of mediterranean cork oak woodlands and their bird communities". Doctoral thesis, University of East Anglia, 2014. http://hdl.handle.net/10451/16152.
Testo completoAbstract (sommario):
Tese de doutoramento (co-tutela), Biologia (Biologia da Conservação), Faculdade de Ciências da Universidade de Lisboa, University of East Anglia, School of Environmental Sciences, 2014Cork oak woodlands are a keystone habitat for Mediterranean biodiversity but are currently undergoing a global decline and widespread management changes driven by social, economic and climatic factors. I examine the effects of both climate and land management changes on cork oak woodlands and their bird communities across the western Mediterranean Basin. Future climatic scenarios indicate that up to 60% of current cork oak woodlands may become unsuitable by 2080, especially in southern areas where they will be restricted to microclimatic refugia sites. Increasing aridity, particularly in drier microclimates, will potentiate a decline of cork oak tree condition resulting in impacts across the food web that ultimately have a negative effect on breeding bird abundance and diversity, particularly for tree-dependent forest species. Farmland and shrubland birds respond mainly to habitat features modified by land management and their abundances increase in areas with open and heterogeneous ground cover. Current abandonment, intensification and overexploitation trends are likely to have negative effects on their populations but climate change can also play an important role if it provides an additional stimulus for land management changes. The unique bird assemblages of North African cork oak woodlands seem particularly vulnerable to both factors and should therefore be considered a conservation priority. Nonetheless, climate change may benefit species of Mediterranean origin and seems to have enabled the establishment of resident populations of traditionally migratory bird species in the Iberian Peninsula. This may provide new conservation opportunities for declining migratory species as long as adequate winter habitat areas are available. Adaptation strategies should aim to incorporate biodiversity-friendly management practices, promote cork oak afforestation in areas that will become climatically suitable and evaluate alternatives to provide similar economic and environmental services in the regions where cork oak woodlands are likely to disappear.
Fundação para a Ciência e a Tecnologia (FCT)
26
McDermott, Molly E. "The Contribution of Agroforestry Systems to Bird Conservation in the Andes". The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1397647503.
Testo completo
27
Peterson, Christine Rose. "Habitat Use By Early Successional Bird Species Along Powerline Rights Of Way: Making Connections Across Private Lands". ScholarWorks @ UVM, 2015. http://scholarworks.uvm.edu/graddis/392.
Testo completoAbstract (sommario):
Wildlife species that rely on early successional habitat are showing long-term region-wide declines, including songbirds such as Eastern Towhee (Pipilo erythrophthalmus), Field Sparrow (Spizella pusilla), Blue-winged Warbler (Vermivora cyanoptera), Golden-winged Warbler (Vermivora chrysoptera), Prairie Warbler (Setophaga discolor), and Brown Thrasher (Toxostoma rufum). All six species are listed as Species of Greatest Conservation Need on a majority of the New England state's Wildlife Action Plans and in 2011, the Golden-winged Warbler was placed under review for federal listing. In areas where vegetation structure is actively maintained in early successional stages, such as powerline rights-of-way (ROWs), there is an opportunity to provide habitat over long time frames. This study focused on habitat use by six early successional bird species in the Champlain Valley in Vermont along powerline ROWs. Thirty sites that included potential habitat were established. During the breeding season, trained citizen scientist volunteers spot-mapped species distribution patterns along transects. Focal habitat use by individuals was mapped during timed field observations (n=83). Vegetation species composition and structure was evaluated within 1m2 vegetation plots across each site (n=965). Logistic regression models of study species' abundance patterns and focal habitat use were compared using Akaike's information criterion (AIC). Surrounding landscape composition, vegetation species composition and vegetation structure had the greatest influence on species abundance and focal habitat use based on best-fit models. All species occurrence, except Blue-winged Warbler and Brown Thrasher, decreased with greater development and fragmentation in the surrounding landscape. While the covariates that influenced habitat use patterns by the species were similar, the effect size and direction of influence varied. These results suggest that a universal management approach for shrubland songbird habitat would not support a broad range of species. The findings from this study determined species-specific habitat preferences that can improve management practices to benefit these declining species.
28
Thomas, Alaina D. "Benefits of the state acres for wildlife enhancement practice for bird populations in Kansas". Thesis, Kansas State University, 2014. http://hdl.handle.net/2097/18720.
Testo completoAbstract (sommario):
Master of ScienceDivision of Biology
Brett K. Sandercock
Grassland birds have experienced population declines worldwide from habitat degradation caused by conversion to agriculture and recent intensification of land use, including increased use of fertilizer, fossil fuels, and irrigation. The U.S. Department of Agriculture, Conservation Reserve Program (CRP) includes initiatives targeting wildlife enhancement to mitigate ongoing declines in grassland bird populations. The newest CRP practice, State Acres for Wildlife Enhancement (SAFE), was designed to restore vital habitats for high priority wildlife species throughout the United States. Our objective was to assess the potential benefits of SAFE for upland gamebirds and grassland songbirds in Kansas. We monitored lands enrolled in SAFE to estimate bird density based on field scale and landscape scale characteristics. Our study was conducted in three ecoregions: Smoky Hills (4 counties), Flint Hills (3 counties), and the High Plains (3 counties). We surveyed 121 SAFE fields and 49 CRP fields from 2012 – 2013. Northern Bobwhite density was negatively associated with percent litter within survey fields. Ring-necked Pheasant density differed among ecoregions, and was positively associated with percent bare ground in the High Plains, but negatively associated with field age in the Smoky Hills. Mourning Dove density differed among ecoregions, and was negatively associated with percent forb in the High Plains, and positively associated with percent grassland in the Smoky Hills. In the Flint Hills, Mourning Doves were negatively associated with CRP fields and large fields. Brown-headed Cowbirds were positively associated with percent forbs. Amount of CRP surrounding survey locations was positively associated with bird density through the entire range for Grasshopper Sparrows, Dickcissels, and Lark Buntings, and in the High Plains for Western Meadowlarks. Percent woodland had negative effects on Western Meadowlarks in the Smoky Hills, whereas percent cropland had negative effects on Eastern Meadowlarks statewide. CRP positively affected abundance of four of our species, whereas percent cropland and woodland negatively affected others. Thus, the amount of set-aside lands enrolled in SAFE could be important for grassland bird populations. SAFE and CRP supported equal numbers of Northern Bobwhites and Ring-necked Pheasants, suggesting SAFE provides benefits for target species of upland gamebirds.
29
Saxton, Valerie Patricia. "Influence of ripening grape compounds on behavioural responses of birds". Phd thesis, Lincoln University. Agriculture and Life Sciences Division, 2004. http://theses.lincoln.ac.nz/public/adt-NZLIU20061207.121738/.
Testo completoAbstract (sommario):
Vineyards in New Zealand suffer bird damage caused by several avian species, including blackbirds and silvereyes. The introduced European Blackbird takes whole grapes which reduces yield. The self-introduced Australasian Silvereye pecks on grapes, leaving them on the vine to be further attacked by fungi and bacteria, and the subsequent off-odours can cause grapes to be refused by the winery or to suffer a price-reduction. Bird control methods remain primitive and largely ineffective during the long ripening period of wine grapes. An ecologically sound method to manage and reduce bird pressure requires deeper understanding of why some birds eat grapes, especially since grapes are not particularly nutritious.
This work investigated the extent to which blackbirds and silvereyes are attracted by various compounds in ripening grapes. Since in natural grapes these compounds develop and change simultaneously, I developed an artificial grape in which a single parameter could be investigated. Artificial grapes (and sometimes nectar) were presented on a bird feeder table and the responses of birds to hexose sugars, the aromas 2-3-isobutylmethoxypyrazine and geraniol, tartaric and malic acids, grape tannins, and purple and green colour were recorded on timelapse video and analysed.
30
Gomez-Sapiens, Martha Marina. "Linking shorebird and marsh bird habitat use to water management in anthropogenic and natural wetlands in the Colorado River delta". Thesis, The University of Arizona, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3623546.
Testo completoAbstract (sommario):
I estimated patterns of shorebird abundance and species diversity in the Colorado River Delta and Upper Gulf of California wetlands in order to determine the relative contribution of intertidal wetlands and non-tidal anthropogenic wetlands to support shorebird habitat use. Species richness varied from 15 to 26 species among sites and 29 species were detected across sites. Density during the peak migration month was higher at the anthropogenic wetland Cienega de Santa Clara (mean = 168 ind/ha, 95% C.I. 29-367), and the intertidal Golfo de Santa Clara (mean = 153 ind/ha, 95% C.I. 17-323). Anthropogenic wetlands (playa and lagoons) supported high abundance of shorebirds along with intertidal wetlands in the Colorado River Delta (mudflats). In contrast, intertidal wetlands farther south on the Sonoran Coast presented lower abundance but higher diversity of shorebird, likely as a result of the higher diversity of habitats (rocky shore, sandy beach, estuary). I modeled water management scenarios for the Cienega in order to determine the response of the dominant vegetation (southern cattail, Typha domingensis Pers.) and the area of the outflow pool below the marsh to different scenarios of water management. The model indicates that if the inflow rate is reduced below the current 4-5 m 3 s-1 the vegetated area of the Cienega that supports habitat for marsh birds would decrease in proportion, as would the area of the outflow pool in the Santa Clara Slough identified previously as shorebird habitat. Increases in salinity will also reduce the vegetated area due to the low salt tolerance of T. domingensis. In winter about 90% of inflow water exits the Cienega into the Santa Clara Slough due to low evapotranspiration contributing to inundate areas that are used by wintering and migrating shorebirds. Lastly, I explored the feasibility of using Vegetation Indices (NDVI and EVI) to model Yuma Clapper Rail detections in the Cienega de Santa Clara as well as the effects of adding other habitat variables and the presence of fire events in the performance of linear models based on NDVI. Both NDVI and EVI were positively related to the Yuma Clapper Rail detections. The relationship was weak to moderate, but significant (P < 0.001), which suggests other factors besides the vegetation condition play an important role in the bird distribution pattern. A model including all the variability among years was a better predictor of the rails detected per transect, than models for fire and non-fire years. We did not find a significant effect from adding habitat features (water % or vegetation %), and we recommend to include variables at both microhabitat level and landscape level, relevant before and during the breeding season in order to increase the explanatory power of models.
31
Gómez, Sapiens Martha Marina. "Linking shorebird and marsh bird habitat use to water management in anthropogenic and natural wetlands in the Colorado River Delta". Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/323444.
Testo completoAbstract (sommario):
I estimated patterns of shorebird abundance and species diversity in the Colorado River Delta and Upper Gulf of California wetlands in order to determine the relative contribution of intertidal wetlands and non-tidal anthropogenic wetlands to support shorebird habitat use. Species richness varied from 15 to 26 species among sites and 29 species were detected across sites. Density during the peak migration month was higher at the anthropogenic wetland Cienega de Santa Clara (mean = 168 ind/ha, 95% C.I. 29-367), and the intertidal Golfo de Santa Clara (mean = 153 ind/ha, 95% C.I. 17-323). Anthropogenic wetlands (playa and lagoons) supported high abundance of shorebirds along with intertidal wetlands in the Colorado River Delta (mudflats). In contrast, intertidal wetlands farther south on the Sonoran Coast presented lower abundance but higher diversity of shorebird, likely as a result of the higher diversity of habitats (rocky shore, sandy beach, estuary). I modeled water management scenarios for the Cienega in order to determine the response of the dominant vegetation (southern cattail, Typha domingensis Pers.) and the area of the outflow pool below the marsh to different scenarios of water management. The model indicates that if the inflow rate is reduced below the current 4-5 m³s⁻¹ the vegetated area of the Cienega that supports habitat for marsh birds would decrease in proportion, as would the area of the outflow pool in the Santa Clara Slough identified previously as shorebird habitat. Increases in salinity will also reduce the vegetated area due to the low salt tolerance of T. domingensis. In winter about 90% of inflow water exits the Cienega into the Santa Clara Slough due to low evapotranspiration contributing to inundate areas that are used by wintering and migrating shorebirds. Lastly, I explored the feasibility of using Vegetation Indices (NDVI and EVI) to model Yuma Clapper Rail detections in the Cienega de Santa Clara as well as the effects of adding other habitat variables and the presence of fire events in the performance of linear models based on NDVI. Both NDVI and EVI were positively related to the Yuma Clapper Rail detections. The relationship was weak to moderate, but significant (P<0.001), which suggests other factors besides the vegetation condition play an important role in the bird distribution pattern. A model including all the variability among years was a better predictor of the rails detected per transect, than models for fire and non-fire years. We did not find a significant effect from adding habitat features (water % or vegetation %), and we recommend to include variables at both microhabitat level and landscape level, relevant before and during the breeding season in order to increase the explanatory power of models.
32
Coluccy, John Matthew. "Reproductive ecology, bioenergetics, and experimental removal of local giant Canada geese (Branta canadensis maxima) in central Missouri /". free to MU campus, to others for purchase, 2001. http://wwwlib.umi.com/cr/mo/fullcit?p3012961.
Testo completo
33
Mayhew, Rebekah Jane Watts. "The species and functional composition of bird communities in regenerating tropical forests". Thesis, University of Stirling, 2017. http://hdl.handle.net/1893/27894.
Testo completoAbstract (sommario):
The widespread threat of species extinctions caused by the destruction and degradation of tropical primary forest (PF) could potentially be mitigated by the expansion of regenerating secondary forest (SF). However, the conservation value of SF remains controversial, and is dependent on many site- and landscape-scale factors, such as habitat age and isolation. The aim of this thesis was to assess the role that SF can play in conserving forest bird communities in central Panama. We study a chronosequence of SF aged 20 – 120-years-old, with sites either isolated from or connected to extensive PF. Our results suggest that SF supports high levels of avian species diversity, and similar community composition to PF. Whilst forest age plays a small role in determining compositional similarity to PF, connectivity to extensive PF was the main determinant of community composition. However, despite high species richness and complex community composition, some specialist PF bird species were consistently absent from SF, and isolated PF. The functional diversity of bird communities did not vary substantially across the forest age and isolation gradient, although we did find some inter-guild differences; with distinct responses in communities of avian insectivores and frugivores. Isolation caused shifts in the trophic traits of insectivores, but resulted in alterations in the dispersal traits of frugivores. The response of bird and tree community composition to forest age and isolation was similar, although isolation had a stronger impact on bird communities. Bird diversity and composition tracked changes in forest structure over succession. When examining the role of birds in seed-dispersal networks, we found bird gape width was the key predictor of seed size consumed. Large-gaped birds consume a wider variety of seed-sizes than small-gaped birds, and small-seeded trees attract a greater number of bird species than large-seeded trees. These results imply high levels of redundancy among small-gaped avian frugivores and small-seeded plant species, but low levels of redundancy among large-seeded plant species and their avian dispersers. This suggests that large-seeded plants may be most at risk of dispersal failure following any change in avian frugivore assemblages. Together, these results suggest that SF can play a key role in sustaining most tropical biodiversity, and in maintaining ecosystem services. Our findings emphasise the importance of integrating SF into conservation strategies to support and buffer tropical PF habitats.
34
Kataoka, Miwa. "Bird Response to the Human Impact in and around Gunung Halimun-Salak National Park, West Java, Indonesia: Implications for Forest Management". 京都大学 (Kyoto University), 2009. http://hdl.handle.net/2433/123871.
Testo completoAbstract (sommario):
Kyoto University (京都大学)0048
新制・課程博士
博士(地域研究)
甲第14752号
地博第72号
新制||地||23(附属図書館)
UT51-2009-D464
京都大学大学院アジア・アフリカ地域研究研究科東南アジア地域研究専攻
(主査)准教授 岩田 明久, 教授 小林 繁男, 准教授 山越 言
学位規則第4条第1項該当
35
Mahjoub, Ghazi. "Using a Sonic Net to Deter Pest Bird Species: Excluding European Starlings from Food Sources by Disrupting their Acoustic Environment". W&M ScholarWorks, 2014. https://scholarworks.wm.edu/etd/1539626954.
Testo completo
36
Saxton, V. P. "Influence of ripening grape compounds on behavioural responses of birds". Diss., Lincoln University, 2004. http://hdl.handle.net/10182/28.
Testo completoAbstract (sommario):
Vineyards in New Zealand suffer bird damage caused by several avian species, including blackbirds and silvereyes. The introduced European Blackbird takes whole grapes which reduces yield. The self-introduced Australasian Silvereye pecks on grapes, leaving them on the vine to be further attacked by fungi and bacteria, and the subsequent off-odours can cause grapes to be refused by the winery or to suffer a price-reduction. Bird control methods remain primitive and largely ineffective during the long ripening period of wine grapes. An ecologically sound method to manage and reduce bird pressure requires deeper understanding of why some birds eat grapes, especially since grapes are not particularly nutritious. This work investigated the extent to which blackbirds and silvereyes are attracted by various compounds in ripening grapes. Since in natural grapes these compounds develop and change simultaneously, I developed an artificial grape in which a single parameter could be investigated. Artificial grapes (and sometimes nectar) were presented on a bird feeder table and the responses of birds to hexose sugars, the aromas 2-3-isobutylmethoxypyrazine and geraniol, tartaric and malic acids, grape tannins, and purple and green colour were recorded on timelapse video and analysed.
37
Ponnikas, S. (Suvi). "Establishing conservation management for avian threatened species". Doctoral thesis, Oulun yliopisto, 2014. http://urn.fi/urn:isbn:9789526203683.
Testo completoAbstract (sommario):
Abstract The protection of endangered species requires knowledge about the habitat requirements and the genetic issues related to the population viability. In this doctoral thesis, I defined the breeding habitat features of the Finnish populations of the Golden Eagle (Aquila chrysaetos) and the Peregrine Falcon (Falco peregrinus) by applying habitat suitability modelling. Secondly, I studied the conservation genetic issues of the Finnish population of the White-tailed Eagle (Haliaeetus albicilla) and the two Reed Bunting subspecies Emberiza schoeniclus witherbyi and E.s. lusitanica met in the Iberian Peninsula. All study populations are classified as threatened according to IUCN classification and they have experienced declines in population sizes in recent history. My results from habitat suitability models showed that human-induced changes in habitat threaten the Golden Eagle in Finland. The relative suitability for the species presence dropped to zero when the proportion of human altered landscape (agricultural or urbanized areas) in the core of the breeding habitat (4 km2) was more than 5%. Models further showed that habitat structure influences breeding habitat selection of the Peregrine Falcon, as it favours well-connected areas of open peatlands. Therefore, fragmentation (i.e., decreasing the connectivity) of open peatlands decreases the habitat quality for the species. The White-tailed Eagle has recovered mainly through local growth, but my results suggest that gene flow from neighbouring populations has had an impact as well, and has enhanced the genetic viability of the Finnish population. The current structure of the two subpopulations (one along the Baltic Sea coast line and another inland in Northern Finland) results mainly from the species’ ecology (i.e., philopatric behaviour), not from the recent population bottlenecks. The effective population size estimate of the coastal subpopulation of White-tailed Eagle was below the critical size needed to maintain evolutionary potential. The estimates of the effective population sizes for E.s. lusitanica and E.s. witherbyi and inland subpopulation of White-tailed Eagle were close or below the critical level of 50, which makes them prone to losing fitness due to inbreeding depression in the short term. Therefore, these study populations need to increase in size in order to secure population viability in the futureTiivistelmä Ihmisen aiheuttamat elinympäristöjen muutokset uhkaavat biodiversiteettiä kasvattamalla yhä useampien eliölajien sukupuuttoriskiä. Tehokkaat suojelutoimenpiteet edellyttävät tietoa uhanalaisten lajien elinympäristövaatimuksista sekä populaation elinkyvylle keskeisistä geneettisistä tekijöistä. Tarkastelen väitöskirjatyössäni maakotkan (Aquila chrysaetos) sekä muuttohaukan (Falco peregrinus) Suomen populaatioiden pesimäympäristön piirteitä maisemaekologisen mallinnuksen avulla. Toiseksi tarkastelen Suomen merikotkapopulaation (Haliaeetus albicilla) sekä Iberian niemimaalla esiintyvien pajusirkun alalajien Emberiza schoeniclus witherbyin ja E.s. lusitanican suojelun kannalta tärkeitä geneettisiä tekijöitä. Kaikki tutkimuspopulaatiot ovat uhanalaisia ja ne ovat kärsineet voimakkaista kannan pienenemisistä. Maisemaekologiset mallit osoittivat maakotkan välttävän ihmisen muokkaamaa ympäristöä (maatalousalueet ja rakennetut alueet). Lajin esiintymistodennäköisyys laski nopeasti nollaan, kun ihmisen muokkaaman ympäristön osuus nousi yli 5 prosenttiin pesimäympäristön ydinalueella (4 km2). Mallit osoittivat maiseman rakenteen vaikuttavan muuttohaukan habitaatinvalintaan, sillä se suosi pesimäympäristönään kytkeytyneitä avosoita. Avosoiden pirstoutuminen (l. kytkeytyneisyyden väheneminen) vähentää näin ollen muuttohaukan pesimäympäristön laatua. Merikotkapopulaatio on toipunut pääosin paikallisen kasvun myötä, mutta tulokseni viittaavat myös siihen, että geenivirta naapurimaiden populaatioista on lisännyt Suomen populaation geneettistä muuntelua. Nykyinen rakenne (rannikon ja Lapin alapopulaatiot) on seurausta lajin synnyinpaikkauskollisuudesta, ei niinkään populaatiokoon romahduksista. Rannikon merikotkapopulaation efektiivinen koko jäi alle kriittisen rajan, joka tarvitaan evolutiivisen potentiaalin säilymiselle. Pajusirkun alalajien sekä Lapin merikotkapopulaation efektiiviset populaatiokoot olivat lähellä kriittisenä pidettyä 50:tä tai jäivät alle, joten ne ovat vaarassa menettää kelpoisuutta sukusiitosdepression seurauksena lyhyellä aikavälillä. Sekä pajusirkun alalajien että merikotkapopulaatioiden tulee sen vuoksi kasvaa säilyäkseen elinvoimaisina tulevaisuudessa
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Hull, Jamie Rebekah. "Can urban greenways provide high quality avian habitat?" Connect to this title online, 2003. http://www.lib.ncsu.edu/theses/available/etd-06052003-131934/.
Testo completo
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Bose, Anushika. "Birds & Blades". Doctoral thesis, Humboldt-Universität zu Berlin, 2021. http://dx.doi.org/10.18452/22458.
Testo completoAbstract (sommario):
Kollisionen von Vögeln mit Windturbinen haben sich zu einer bedenklichen Quelle für die Gefährdung besonders von Populationen seltenerer Vogelarten entwickelt. Allerdings wird im Allgemeinen auch bestätigt, dass die Nutzung der Windenergie unverzichtbar ist. Das Hauptziel dieser Arbeit war es, die Relevanz der Wechselwirkungen zu verstehen, die zwischen technischen Infrastrukturen und den von Kollisionen betroffenen Vogelarten auf der Landschaftsebene stattfinden. Da sowohl von der Landschaft beeinflusst werden. Unter Nutzung der durch gezielte Nachsuche gefundenen Opfer der am häufigsten von Kollisionen betroffenen Artengruppen paradoxerweise as als Proxy für das Vorkommen von Arten, und Durch die Anwendung verschiedener Techniken zur Modellierung der Artenverbreitung (SDMs) die “kollisionsempfindliche Nische “für jede der Vogelgruppen beschrieben. Obwohl die vorhergesagten Gebiete mit potenziellen Kollisionsrisiko insgesamt nur kleine, aber stark verteilt im ungefährdes Bundeslandes hatten. Greifvögel mit die breiteste Nische, die zudem signifikante Überlappungen mit den kollisionsempfindlichen Nischen der anderen Gruppen aufwies. Die niedrig bewerteten Gebiete weiter differenziert, die als tatsächliche „Bereiche ohne Risiko“ interpretiert wurden, für weitere geplante Winkraftanlagen. Zusätzlich die jeweiligen Potentiale und Gefärdungen für Kollisionen auf der Basis der regionalen Dichteverteilungen der Arten in Brandenburg mit Ensemble-Methoden von Boosted Regression Trees wird ebenfalls bewertet. Zusammenfassend, diese Analysen paradigmatisch, sowohl die Gebiete als auch die Entfernungen zu den Grenzlinien der verschiedenen Landnutzungsformen ein höheres Risiko für die Kollision von Individuen der untersuchten Arten mit Windkraftanlagen ergibt ermitteln . Dieser Ansatz kann es möglich machen, zukünftige Windparkerweiterungen in der Landschaft im die möglichst kollisionsfreie und naturverträglicheStandorte in der Landschaft.Although, it is well recognized that harnessing wind energy is highly indispensable, but collisions of birds at wind turbines has also developed simultaneously, concerning multiple bird species. With wind being strongly affected by the landscape and the behaviour of birds also being strongly influenced by the landscape, the main objective of the thesis was to understand the relevance of interactions between wind energy infrastructures and bird species from an ecological perspective of the landscape. Utilizing the carcass collision datasets of the frequently-hit bird-groups paradoxically as proxies for species presence, collision sensitive ecological distances to different land-use types were ascertained, by employing multiple techniques of species distribution modelling (SDMs), to delineate their respective collision sensitive niche employing the capabilities of machine learning algorithms. The predicted areas were specialized and highly dispersed across the federal state, with raptors showing the broadest niche and significant overlaps with the other groups. Based on estimated collision probabilities of the assessed areas (between 0 and 1), further segregations differentiated only those areas with negligible collision probabilities, <0.05, which were interpreted as the actual "no risk areas, suggesting any further planned additions of wind turbines to be suitably positioned only in these “safer” areas. Additionally, these collision probabilities were translated to strike susceptibilities, by relating them to the regional density distributions of the species as well. Summarizing, these analyses paradigmatically ascertained collision risk areas, and especially the collision sensitive distances from different land-use types to these areas, enabling the accurate guidance of future wind farm expansions in the landscape. Ultimately, formulating novel wind turbine allocation strategies to minimize avian collisions, making them as compatible as possible.
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Rehfisch, Marc Mansel. "A study of the benthic community, with particular reference to the chironomidae, of shallow, brackish lagoons created for the management of a bird reserve". Thesis, University of Hull, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304408.
Testo completo
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Juarez, Berrios Edwin Alfredo. "Habitat relationships of seven breeding bird species in the Leon River Watershed investigated at local scales". Texas A&M University, 2004. http://hdl.handle.net/1969.1/1574.
Testo completoAbstract (sommario):
Over the past 100150 years Texas rangelands have dramatically changed from native open savannahs to dense woodlands. On the Edwards plateau, a major management concern is the increasing encroachment of Ashe juniper (Juniperus ashei). Preceding an anticipated brush management program, I investigated the presence, co-occurrence, and habitat relationships of 7 breeding bird species in the Leon River Watershed in central Texas, USA: black-capped vireo (Vireo atricapillus), golden-cheeked warbler (Dendroica chrysoparia), northern bobwhite (Colinus virginianus), white-eyed vireo (Vireo griseus), Bells vireo (Vireo bellii), painted bunting (Passerina ciris), and brown-headed cowbird (Molothrus ater). Vegetation characteristics were compared between sites occupied by each species and unoccupied sites using univariate analysis. Models for predicting species site occupancy were developed (using logistic regression) based on habitat characteristics correlated with the presence of each species. Two species of special concern, the endangered black-capped vireo and golden-cheeked warbler occupied 5.6% of sites and 13.8% of sites respectively, while the brood parasite brown-headed cowbird was the most widespread, occupying 86.8% of sites. Species co-occurrence patterns revealed significant associations between the golden-cheeked
warbler and each of 5 other species. For most species, variables included in habitat models could be explained by knowledge of species known habitat associations. For example, the black-capped vireo was positively associated with increasing low-growing (<1.5 m) hardwood cover and with Low Stony Hill ecological sites. The golden-cheeked warbler was positively associated with increasing density of larger juniper trees, increasing variability in vertical vegetation structure, and decreasing midstory canopy of deciduous nonoaks (e.g., cedar elm [Ulmus crasifolia]). It also preferred Low Stony Hill and Steep Adobe ecological sites. Site occupancy seemed to be driven by variables that describe overall vegetation structure. In particular, cover of low-growing non-juniper vegetation and juniper tree density appeared to be important in determining site occupancy for several species. Although the models constructed were not very robust, resource managers can still benefit from such models because they provide a preliminary examination of important controlling variables. Managing rangelands to maintain or restore a mosaic of juniper patches and open shrublands are likely to help meet the habitat requirements of these bird communities.
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Little, Ian Tchagra. "Bird reproductive success and faunal habitat selection as tools for understanding the impacts of land-use management on moist highland grassland biodiversity in South Africa". Doctoral thesis, University of Cape Town, 2011. http://hdl.handle.net/11427/11407.
Testo completoAbstract (sommario):
It has been suggested that natural fires in these grasslands would have occurred as infrequently as every four or more years. Currently, the majority of the system is managed by livestock farmers who burn their land annually at the onset of the rainy season (early in the austral summer).
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Ross, Jeremy D. "The Evolutionary History, Demographic Independence and Conservation Status of Two North American Prairie Bird Species: The Greater Prairie Chicken and the Lark Sparrow". Bowling Green State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1303855437.
Testo completo
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Lolya, Lewis Matthew. "Assessing Avian Responses to Habitat Management Along Pipeline Right-of-ways in Eastern Ohio". The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1556739587776114.
Testo completo
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Pearse, Aaron Todd. "Design, evaluation, and applications of an aerial survey to estimate abundance of wintering waterfowl in Mississippi". Diss., Mississippi State : Mississippi State University, 2007. http://sun.library.msstate.edu/ETD-db/ETD-browse/browse.
Testo completo
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Batdorf, Katharine E. "Distributional Changes in Ohio's Breeding Birds and the Importance of Climate and Land Cover Change". The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1354560319.
Testo completo
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Owen, Jenny. "Provision of habitat for black grouse Tetrao tetrix in commercial forest restocks in relation to their management". Thesis, University of Stirling, 2011. http://hdl.handle.net/1893/3444.
Testo completoAbstract (sommario):
As planted forests mature and are clearfelled in patches, second rotation tree crops (restocks) become available to black grouse, a species of conservation concern in the UK. Currently, only a limited amount is known about the resources provided by this habitat to black grouse and their broods. The aims of this study therefore, were to investigate the recovery of field-layer vegetation and the invertebrate population from restock through to canopy closure of planted trees, assess the duration of habitat availability and food resources to black grouse, and understand how forest management could improve provision. Changes to the abundance of predators resulting from habitat management were also considered. The comparative habitat quality of restocks was assessed in a wider landscape context. Field-layer vegetation in 72 restocks in two afforested areas in the north-east and the south-west of the Scottish Highlands was surveyed. On average, only 60% of ground in restocks was re-planted with second rotation trees, with the remainder left unplanted. Initial vegetation recovery was generally impeded by timber harvest residues (mainly brash), which comprised up to 50% of total ground cover two years after restock. Increased cover of heather Calluna vulgaris, often an important component of black grouse habitat, and decreased brash cover were recorded in areas of restocks where first-rotation timber was removed by cable-winch (compared with harvester and forwarder removal) and in planted areas (compared with areas left unplanted). Bilberry Vaccinium myrtillus and cotton grass Eriophorum spp. occurrence was recorded infrequently irrespective of restock age or management. Heather generally dominated the field-layer six years after restock, reaching a height and density reported to be suitable for black grouse nesting and brood cover in other studies. The onset of tree canopy closure as early as eight years suggests that suitable black grouse habitat availability in restocks is likely to be severely limited in duration. Brash removal, or break-up and re-distribution of the brash layer, positively affected the recovery of field-layer vegetation species potentially of use to black grouse. Extending the fallow period prior to restock resulted in an extended period of suitable habitat available to black grouse prior to canopy closure. However, habitat created by extending the fallow period also attracted a higher number of mammalian predators of black grouse. In the longer term, areas of restocks left unplanted should provide a valuable open-ground resource after canopy closure of the planted crop, although results suggest that management to prevent encroachment of naturally regenerating non-native trees is likely to be necessary. Invertebrate taxa selected by chicks in previous black grouse studies were available in all ages of restock studied. Taxa abundance differed as restocks aged and field-layer vegetation developed, although contrasting habitat preferences of taxa meant that each was affected differently by restock management. No single forest management method positively increased abundance of all taxa. Abundance of Lepidoptera larvae, a key food item for black grouse chicks, was positively related to dwarf shrub cover. An extended fallow period prior to restock should prolong increased larvae availability to chicks. Provision of preferred field-layer vegetation habitat and invertebrate abundance in restocks was comparable to habitat surrounding leks - areas likely to be occupied and utilised by black grouse. Restocks had a comparatively low occurrence of key plant species, including bilberry Vaccinium myrtillus and cotton grass Eriophorum spp. Cover of the dwarf shrub bog myrtle Myrica gale, positively associated with Lepidoptera larvae abundance in habitat surrounding leks, was absent from restocks. The abundance of other invertebrate taxa considered was similar between leks and restocks. Study findings are discussed with reference to black grouse conservation and commercial forestry systems in Europe. Management recommendations to improve habitat for black grouse in second rotation planted forests in Britain are provided.
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Forssén, Annika. "Betydelse av lövinslag, död ved och variation i träddiameter för artrikedomen hos småfåglar". Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-69560.
Testo completoAbstract (sommario):
Forest management contributes to the changes in forest structure by turning heterogenous forests of varied age into homogenous forests of similar age and thus affect bird species depending on different structures or habitats which are lost during forestry. In this report, a study was made to investigate how the amount of decidious trees, dead wood and variation in tree diameter affect bird diversity. The purpose of this study was to be able to give forest management guidelines to increase bird diversity. This study was conducted by investigating 65 transects in forests of different structure south of Linköping, Sweden. Along the 65 transects, birds were inventoried as well as the vegetation. The trees were measured in 5 circles along each transect. The data from the investigations both on birds and vegetation were analysed by using generalized linear models. The results showed that amount of deadwood and variation in tree diameter had the strongest effects on bird diversity, and to some extent the amount of decidious trees. By applying this knowledge of the positivt effects on birds when increasning the amount of deadwood, decidious trees and variation in tree diameter in the forests, it is possible to create better conditions for maintaining species richness and diversity.
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Husak, Michael Scott. "Factors influencing avian community structure in bottomland hardwood forests of the southeastern United States". Diss., Mississippi State : Mississippi State University, 2007. http://library.msstate.edu/etd/show.asp?etd=etd-04042007-105455.
Testo completo
50
Broshot, Nancy Ellen. "The Effects of Urbanization and Human Disturbance Upon Plant Community Structure and Bird Species Richness, Diversity, and Abundance in a Natural Forested Area (Forest Park) in Portland, Oregon". PDXScholar, 1999. https://pdxscholar.library.pdx.edu/open_access_etds/3962.
Testo completoAbstract (sommario):
The effects of urbanization and continual human disturbance on the plant and avian communities of Forest Park and forested lands surrounding Portland, Oregon, were studied. I examined characteristics of plant and avian communities at 25 sites, 24 which were in Forest Park and surrounding areas and one which was in the Ancient Forest Preserve (old-growth stand) northwest of Forest Park. Data were analyzed using multiple regression, ANOV A, and Bonferonni/Dunn. Seven variables were selected representing different urbanization gradients. An additional covariable coded for the old-growth stand, allowing it to be used as a control.
Many tree variables, especially those related to shade-tolerant species, were positively correlated with both the distance from downtown Portland and the number of houses in the surrounding area, and negatively correlated with the distance from the nearest forest edge; however, many shrub and herbaceous variables were negatively correlated with the distance from downtown Portland. Species diversity for herbaceous and shrub species was greater at more urban sites, but diversity of trees was lower at more urban sites. There were significantly more non-native species of plants in the city section. I found significantly fewer saplings and small trees, especially shade-tolerant species, in the section of Forest Park closest to downtown Portland, although tree mortality was positively correlated with distance from Portland.
Summer bird data revealed significant increases in the abundances of urban and edge species at more urban sites, with concomitant reductions in forest species. There were significantly more ground gleaning birds and short distance migratory species. I also found a significantly greater abundance of birds in the old-growth stand during the winter. This increase was positively correlated with the depth of snow in the nearby Cascade Mountains.
My results indicate that Forest Park is apparently progressing in a normal successional pattern with the exception of the city section. The reduction in shade tolerant saplings and small trees in the city section suggest that rate of succession has been slower at more urban sites. Avian data suggest that urbanization affects bird species abundance and guild composition in the more urban areas.