249 research outputs found
Vaux’s Swift migratory connectivity
No full textThe strength of migratory connectivity between breeding, stopover, and wintering areas can have important implications for population dynamics, evolutionary processes, and conservation. For example, patterns of migratory connectivity may influence the vulnerability of species and populations to stochastic events. For many migratory songbirds, however, we are only just beginning to understand patterns of migratory connectivity. Here, we investigate the potential strength of migratory connectivity within a population of Vaux’s Swifts (Chaetura vauxii). Vaux’s Swifts, like many aerial insectivores, are currently experiencing population declines, and a mass mortality event at a spring migratory roost on Vancouver Island, British Columbia, Canada, resulted in the death of over 1,000 individuals, representing some 2% of the British Columbia population. From these individuals, we examined variation in three stable-isotopes (δ2H, δ13C, and δ15N) from claw samples in order to determine whether spring migrants showed inherent isotopic similarity of the habitats they used on their Mexican and Central American wintering grounds. Our results indicated the presence of two to three broad isotopic clusters, suggesting that Vaux’s Swifts migrating through Vancouver Island most likely originated from two or three over-wintering locales or habitat types. We found no evidence of sex- or morphology-based segregation, suggesting that these different groups likely share a similar overwintering ecology and thus may be equally vulnerable to stochastic events or habitat loss on the wintering grounds. Our results highlight the need for more studies on the non-breeding season ecology and migratory connectivity of this species.articlesaccepted for publicationVaux’s Swiftmigratory connectivitycluster analysisstable isotopeconservationroos
Vaux’s Swift migratory connectivity
No full textPopulations of Vaux’s Swift (Chaetura vauxi), like those of many aerial insectivores, are rapidly declining. Determining
when and where populations are limited across the annual cycle is important for their conservation. Establishing the
linkages between wintering and breeding sites and the strength of the connections between them is a necessary first
step. In this study, we analyzed 3 stable isotopes (δ13C, δ15N, δ2H) from feathers collected during spring migration from
Vaux’s Swifts that perished during a stopover on Vancouver Island, British Columbia, Canada. We previously analyzed
claw tissue (grown during winter) from the same individuals, revealing that the swifts likely wintered in 2 or 3 locations/
habitats. Here, we used stable isotope analysis of flight feathers presumed to have been grown on, or near, the breeding
grounds to determine the likely previous breeding locations and presumed destinations for the swifts. Stable isotope
values (δ13C, δ15N, δ2H) showed no meaningful variation between age classes, sexes, or with body size. Surprisingly, ~26%
of the birds sampled had feather isotope values that were not consistent with growth on their breeding grounds. For the
remaining birds, assigned breeding origins appeared most consistent with molt origins on Vancouver Island. Overall, migratory connectivity of this population was relatively weak (rM = 0.07). However, the degree of connectivity depended on
how many winter clusters were analyzed; the 2-cluster solution suggested no significant connectivity, but the 3-cluster
solution suggested weak connectivity. It is still unclear whether low migratory connectivity observed for Vaux’s Swift and
other aerial insectivores may make their populations more or less vulnerable to habitat loss; therefore, further efforts
should be directed to assessing whether aerial insectivores may be habitat limited throughout the annual cycle.Peer reviewedarticlespublishedVaux’s Swiftaerial insectivoresChaetura vauximigrationmigratory connectivitypopulation declinesstable isotopesstopove
Condor (RoCH Fans and Legends)
No full textCondor (RoCH Fans and Legends) (2015, site-specific drawing, chalk on wall) forms part of the project, 'RoCH Fans and Legends', a body of work commissioned for two solo exhibitions staged at QUAD, Derby, in 2015 and CFCCA (Centre for Chinese Contemporary Art), Manchester, 2016. The project draws on the prolific film and television adaptations of The Condor Trilogy (1957-61), a classic ‘new wuxia’ epic by Louis Cha aka Jin Yong, to explore the genre’s recurring tropes and translations in diasporic popular culture.
Exhibited works included single-channel and multi-channel moving image for gallery and online, site-specific drawing and wallpaper, a limited edition concertina multiple, and an unlimited artist e-book. Works are listed as individual Art/Design items: RoCH Fans & Legends (Entries / Variations), 2013/18 hand-finished inkjet prints; Drawings, 2014; Covers I and II, 2015, animated drawings; Trailers, 2015, single-channel video, 4 mins; Trilogies, 2015, 3-screen moving image installation, 65 mins; Condor, 2015, chalk on wall; RoCH Fan, 2015, concertina multiple; RoCH Fans and Legends, 2017, unlimited artist freeebook
Hardwarekeuze voor het El Condor Soundsystem: Aanbevelingsrapport voor optimale hardware
No full textProfessionele muzikanten gaan naar een opnamestudio als ze een album willen opnemen van hoge geluidskwaliteit. Voor de beginnende muzikant zijn deze studio’s echter niet te betalen, aangezien een opname minstens \u801500 kost. Het aanschaffen van eigen opnameapparatuur is nog vele malen duurder. In die hoge prijs gaat het El Condor Soundsystem verandering brengen. Het El Condor Soundsystem is een draagbaar apparaat, dat een ruimteopname van gespeelde muziek vastlegt, bewerkt en opslaat als bestand dat leesbaar is op elke PC. Het El Condor Soundsystem kan dankzij zijn algoritmes verschillende bronnen onderscheiden zonder hier een fysieke verbinding mee te hebben. De verschillende geluidssporen worden gebruikt om de muziek automatisch te verfraaien en daarna worden deze weer gemixt tot één eindproduct met CD-kwaliteit. Voor het bewerken en wegschrijven is veel rekenkracht nodig. Daarom wordt in dit rapport antwoord gegeven op de vraag: met welke hardware kun je het El Condor Soundsystem zo efficiënt (en dus goedkoop) mogelijk implementeren?EEMicroelectronics & Computer EngineeringElectrical Engineering, Mathematics and Computer Scienc
Representing, resisting and reproducing ethnic nationalism: Official UK Labour Party representations of ‘multicultural Britain’.
No full textIn this paper I argue that any attempt to resist racialization needs to take account of the complex and often paradoxical ways in which notions of race and culture come to be articulated in conjunction with categories of nation, state and society. In the first half of the paper I consider some of the strategies used by UK Labour Party Ministers to counter ethnic representations of British identity by promoting the fact and value of post-Imperial Britain as a ‘multicultural society’. In the second half of the paper I consider some tensions within these arguments. First, I consider how the rhetorical formulations that the speakers use to justify the political project of UK multiculturalism implicitly presuppose a natural order in which nations are populated by a racially and culturally homogenous people. Second, I consider how their prescriptive recommendations that ‘we’ recognize and celebrate ‘our’ ethnic diversity do not in practice seek to establish the ultimate fiction of ethnic nationalism as a general ideological principle, but rather treat the fact and value of ethnic diversity as a uniquely British asset or virtue, in a manner that closely echoes the selfcelebratory rhetoric of British imperialism. Despite the claim that an ethnically neutral understanding of ‘British society’ will necessarily also entail a rejection of ‘insular nationalism’, paradoxically these banally nationalized liberal utopian discourses of multiculturalism are in some respects more Anglocentric and less internationalist than the explicitly racialized versions of British identity promoted by the far right British National Party
Predicting condor range expansion in California to reduce development threats
No full text2020 Summer.Includes bibliographical references.Collisions with wind energy infrastructure is a major cause of wildlife mortality worldwide and especially pose threats to bird and bat populations. Avian species that have associations with habitats that generate strong winds are at higher risk of collision with wind turbines. Critically endangered California condors (Gymnogyps californianus) are among species that use areas with high-class winds. As the condor's population growth continues to face challenges, it is imperative that managers working with the California Condor Recovery Program identify and reduce all threats to the species and foster conditions that promote condor recovery. Renewable energy projects, particularly wind energy, pose risks to condors; and new developments within current, documented condor range require planning and consultation with the United States Fish and Wildlife Service. However, industrial-scale wind energy projects in California consider condor flocks in central and southern California separate and statically persisting within their current ranges. This misconception may result in development within condor habitat that is detrimental to range expansion and recovery. In this thesis, I examine factors that influence condor home range sizes, predict where condors are likely to expand their range within identified suitable habitat in California, and assess where the predicted condor range overlaps with areas that generate high-class winds preferred for wind energy development. My first chapter focuses on estimating annual home ranges of condors and identifying factors that influence home range size. Understanding what intrinsic and extrinsic variables influence condor home ranges can inform management planning and aid in predicting condor range expansion. I used location data collected from condors released in central and southern California to estimate annual condor home range area and assessed twenty-one variables related to individual characteristics, management factors, population dynamics, and habitat suitability to identify strong predictors of home range size. I found that age group, time spent in the wild, age of managing agency, maximum slope, maximum NDVI, distance to water, and road density were significant predictors of annual home range area. On average, adult breeding condors had the smallest home range areas and subadult condors had the largest home range areas. Population size did not affect annual home range size of condors; however, home range size increased the longer a managing agency had been releasing condors. My objective of the second chapter was to predict condor range expansion in California and identify where there may be conflict between condors and potential wind energy development. Predicting condor range expansion may inform managers of areas to concentrate efforts and resources for management and outreach, as well as identify areas that should be considered during wind energy development planning stages to reduce risks to condor recovery. I used the results from Chapter 1 and a habitat suitability surface to create a tool in which a user can customize the demographics of condor flocks in California sometime in the future and predict the overlapping home ranges of individuals in the flocks. Users can then export the predicted ranges into a GIS program to consider how the overlapping home ranges may be affected by plans for wind energy development and identify possible alternative sites. I predicted condor range expansion in California under four scenarios: 1) population size and structure stays the same (2019 California population); 2) each flock has 150 individuals with 15 breeding pairs; 3) each flock has a majority of breeding pairs, which maximizes breeding pairs and minimizes sub-adult condors; and 4) each flock has a majority of subadults, which maximizes subadult condors and minimizes breeding pairs. Predicted ranges under different scenarios exhibited high similarity and areas with high-class wind generation overlapped with <10% of predicted condor range under all scenarios. More than 81% of areas with strong winds suitable for energy generation were unaffected by predicted condor range, suggesting there are alternative areas for wind energy development with less risk of conflict with critically endangered California condors
Study area, background area for developing a California condor landscape conductance surface (dark gray), in-flight California condor locations (July 2013-May 2017), and release sites.
No full textStudy area, background area for developing a California condor landscape conductance surface (dark gray), in-flight California condor locations (July 2013-May 2017), and release sites.</p
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Resource Selection by the California Condor (Gymnogyps californianus) Relative to Terrestrial-Based Habitats and Meteorological Conditions
No full textCondors and vultures are distinct from most other terrestrial birds because they use extensive soaring flight for their daily movements. Therefore, assessing resource selection by these avian scavengers requires quantifying the availability of terrestrial-based habitats, as well as meteorological variables that influence atmospheric conditions necessary for soaring. In this study, we undertook the first quantitative assessment of habitat- and meteorological-based resource selection in the endangered California condor (Gymnogyps californianus) within its California range and across the annual cycle. We found that condor use of terrestrial areas did not change markedly within the annual cycle, and that condor use was greatest for habitats where food resources and potential predators could be detected and where terrain was amenable for taking off from the ground in flight (e.g., sparse habitats, coastal areas). Condors originating from different release sites differed in their use of habitat, but this was likely due in part to variation in habitats surrounding release sites. Meteorological conditions were linked to condor use of ecological subregions, with thermal height, thermal velocity, and wind speed having both positive (selection) and negative (avoidance) effects on condor use in different areas. We found little evidence of systematic effects between individual characteristics (i.e., sex, age, breeding status) or components of the species management program (i.e., release site, rearing method) relative to meteorological conditions. Our findings indicate that habitat type and meteorological conditions can interact in complex ways to influence condor resource selection across landscapes, which is noteworthy given the extent of anthropogenic stressors that may impact condor populations (e.g., lead poisoning, wind energy development). Additional studies will be valuable to assess small-scale condor movements in light of these stressors to help minimize their risk to this critically endangered species
Resource selection by the California condor (Gymnogyps californianus) relative to terrestrial-based habitats and meteorological conditions.
No full textCondors and vultures are distinct from most other terrestrial birds because they use extensive soaring flight for their daily movements. Therefore, assessing resource selection by these avian scavengers requires quantifying the availability of terrestrial-based habitats, as well as meteorological variables that influence atmospheric conditions necessary for soaring. In this study, we undertook the first quantitative assessment of habitat- and meteorological-based resource selection in the endangered California condor (Gymnogyps californianus) within its California range and across the annual cycle. We found that condor use of terrestrial areas did not change markedly within the annual cycle, and that condor use was greatest for habitats where food resources and potential predators could be detected and where terrain was amenable for taking off from the ground in flight (e.g., sparse habitats, coastal areas). Condors originating from different release sites differed in their use of habitat, but this was likely due in part to variation in habitats surrounding release sites. Meteorological conditions were linked to condor use of ecological subregions, with thermal height, thermal velocity, and wind speed having both positive (selection) and negative (avoidance) effects on condor use in different areas. We found little evidence of systematic effects between individual characteristics (i.e., sex, age, breeding status) or components of the species management program (i.e., release site, rearing method) relative to meteorological conditions. Our findings indicate that habitat type and meteorological conditions can interact in complex ways to influence condor resource selection across landscapes, which is noteworthy given the extent of anthropogenic stressors that may impact condor populations (e.g., lead poisoning, wind energy development). Additional studies will be valuable to assess small-scale condor movements in light of these stressors to help minimize their risk to this critically endangered species
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