Paz Jesica AndreaSeco Pon Juan PabloKrüger LucasFavero Marco...
11页查看更多>>摘要：ABSTRACT Sexual segregation in habitat use occurs when sexes differ in their use of the physical environment and is widely reported among seabirds. The Black-browed Albatross (Thalassarche melanophris) is one of the most abundant seabird species in the south-west Atlantic, but whether the sexes differ in their habitat selection during winter remains unknown. Here, we tested for sexual segregation in adult and immature Black-browed Albatrosses during winter. Movement data from 21 satellite-tracked Black-browed Albatrosses across the south-west Atlantic Ocean between 2011 and 2015 were used to determine suitable foraging habitat for males (n?=?7) and females (n?=?14) using habitat selection models. Sexual segregation was then assessed using an index of niche overlap for immature and adult age classes. Variables with the highest importance in habitat selection models across all groups were depth and sea surface temperature. The highest probabilities of occurrence were in shallow waters and intermediate surface temperatures. No sexual segregation was found which may be because of the large abundance of prey in the region and moderate energy requirements during the non-breeding season. These results are relevant for spatially explicit conservation management in this region, including the designation of marine protected areas. Indeed, bycatch in fisheries is a major threat to seabirds in this area, and foraging behaviour and performance in winter of this keystone species will influence their future reproductive performance.
原文链接:
NSTL
Taylor & Francis
Stojanovic DejanNeeman TeresaHogg Carolyn J.Everaardt Annika...
9页查看更多>>摘要：ABSTRACT Living in a captive environment may compromise phenotypic traits critical to survival in the wild. Captive animals that differ from the ideal wild phenotype may have impaired fitness after release, especially if there is extreme phenotypic selection during some life history stages. Wing shape of migratory birds is crucial to migration efficiency, and changes to wing shape in captivity may severely affect survival after release. We investigate wing shape of migratory Orange-bellied Parrots Neophema chrysogaster in captivity and the wild. The first two flight feathers were shorter in captive birds, and the fifth and sixth feathers were longer than wild conspecifics. These differences altered wing shape, producing a more proximal tip and a more convex trailing edge than the wild phenotype, which likely alters flight performance. This wing shape contravenes expectations from general patterns of wing shape in migratory birds. Wing shape in the captive birds sampled was independent of inbreeding, generations in captivity and ancestry. Captive environments may affect feather development or impose some selective pressure on wing shape. Alternatively, release from intense phenotypic selection during migration may allow parrots with wing shapes poorly adapted to migration to survive and breed in captivity. Altered wing shape may contribute to low observed survival of parrots released to the wild.
原文链接:- NSTL
- Taylor & Francis
Jackson Micha V.Woodworth Bradley K.Bush RobertClemens Robert S....
11页查看更多>>摘要：ABSTRACT Shorebirds in the East Asian-Australasian Flyway have experienced population declines linked to loss of coastal wetlands. Despite this vulnerability to habitat loss, shorebirds regularly use artificial habitats, especially for high-tide roosting. Understanding the distribution of shorebirds in artificial versus natural roosts could inform habitat management strategies aimed at population recovery. We analysed time-series of high-tide shorebird monitoring data from five developed regions of Australia where artificial habitat use has previously been documented and made three key discoveries. First, artificial habitat use was generally high across the regions, with >50% of the average proportion of the regional population of 39 of 75 species-region combinations (52%) using artificial habitats at high tide. Second, in 84% of species-region combinations the average proportion of birds that used artificial habitats from the time of their establishment onward did not show a significant temporal trend. Third, migratory and coastal specialist species showed lower proportional artificial habitat use than non-migratory and generalist/inland specialist species. These findings showing consistent, widespread use of artificial habitats by large shorebird aggregations at high tide suggest that a framework for high-tide habitat management that includes artificial habitats alongside preservation of remaining natural habitats could make a significant contribution to shorebird conservation in Australia.
原文链接:- NSTL
- Taylor & Francis
Clemens Robert S.Rogers Danny I.Minton Clive D. T.Rogers Ken G....
12页查看更多>>摘要：ABSTRACT Many migratory shorebird species using the East Asian–Australasian Flyway are declining rapidly. While the loss of staging habitats in East Asia is considered the primary cause, stressors to fitness often occur throughout the geographic range of declining species, and threats in the non-breeding grounds have been comparatively poorly studied. Three species of migratory shorebird, Curlew Sandpiper (Calidris ferruginea), Sharp-tailed Sandpiper (C. acuminata) and Red-necked Stint (C. ruficollis), use Australia’s dynamic temporary wetland systems opportunistically, yet these large wetland systems have become increasingly degraded, with reduced frequency and extent of flooding. Here, we test whether variables related to wetland availability in Australia’s interior can explain annual variation in apparent survival, abundance or immature to adult ratios at three well-monitored coastal shorebird areas in southern Australia (total area > 1315 km2). We show that coastal annual bird abundance and ratios of immatures at the coast were higher when inland Australia was relatively hot and dry. Also, a small but significant amount of variation in annual apparent survival can be explained by annual variation in inland conditions, with higher survival rates in years when inland conditions were relatively wet and cool. For the endangered Curlew Sandpiper, the impacts of Australian environmental conditions may be exacerbating the impacts of conditions experienced in other parts of its range on fitness and survival. While the effects we document here are relatively weak, they do suggest that management of inland wetlands for these shorebirds may positively affect survival rates of these sharply declining species.
原文链接:- NSTL
- Taylor & Francis
Jauregui AdriánGonzalez ExequielSegura Luciano N.
8页查看更多>>摘要：ABSTRACT The European Starling (Sturnus vulgaris) – hereafter ‘starling’ – has been introduced in many countries, and its South American population recently started expanding exponentially. This invasive species has a worldwide negative impact on the breeding performance of woodpeckers, competing for cavity use. Nevertheless, information is still lacking regarding southern temperate neotropical woodpeckers nest defence strategies and starling effects on woodpeckers’ breeding performance. We monitored Campo Flicker (Colaptes campestris) and Green-barred Woodpecker (Colaptes melanochloros) nests in a native southern temperate forest of central-eastern Argentina, to detect interactions with starlings and to assess the effect of starlings presence on woodpeckers’ breeding performance. We assessed whether woodpeckers perform defensive behaviours against the starlings by exposing taxidermied starling models to woodpecker breeding pairs. We detected interactions with starlings at 11% of the nests. These nests had a significantly higher probability of being abandoned during the early stages (until the third incubation day), compared to nests without interactions. Moreover, woodpeckers attacked and made distress calls more frequently in response to the presentation of the starling, compared to predator and non-competing species models. We also documented evidence of joint nesting, as four breeding pairs of woodpeckers shared their nest chamber with starlings. Our results indicate that neotropical woodpeckers are more likely to abandon their cavity when they interact with starlings. As the starling is expanding quickly in Argentina, this information points at the need to develop management programmes to control the impacts of this invasive species on the native fauna, especially on species with conservation concerns.
原文链接:- NSTL
- Taylor & Francis
Friesen Megan R.Simpkins Craig E.Ross JamesAnderson Sandra H....
8页查看更多>>摘要：ABSTRACT Accurate and repeatable population estimates are key to establishing population trends and conservation status. Rako, or Buller’s Shearwater (Ardenna bulleri) is a seabird endemic to New Zealand that breeds only on the Poor Knights Islands, but forages throughout wider areas of the Pacific Ocean during the non-breeding season. The lack of threats on the breeding grounds and the wide foraging range of Buller’s Shearwaters makes them ideal sentinels of ocean health. Although they are commonly seen at sea and the population in the 1980s was thought to be around 2.5 million birds, other rapid land-based surveys suggested a much lower figure (~100,000 pairs on Aorangi), and no thorough population estimate has been undertaken to date. We calculated a population estimate for Buller’s Shearwater based on burrow counts and state of occupancy conducted at the Poor Knights during either the 2016–2017 or the 2017–2018 breeding seasons. We incorporated information on habitat availability and preference in population models. Our estimate of 78,645 (95% confidence interval 67,176–89,178) active burrows, broadly representing breeding pairs, is lower than some previously published assessments. This is a repeatable quantitative study of the Buller’s Shearwater breeding population, including breeding activity, and provides critical baseline data to determine population trends for this potentially important marine indicator species.
原文链接:- NSTL
- Taylor & Francis
Leseberg Nicholas P.McAllan Ian A. W.Murphy Stephen A.Burbidge Allan H....
11页查看更多>>摘要：ABSTRACT Shortfalls in our knowledge of the most basic parameters, such as overall range and population size, ensure evidence-based conservation of poorly known or ‘missing’ species is inherently difficult. Often, the only source of such knowledge is anecdotal reports, which are usually considered too unreliable to be of value. Methods that help conservation decision-makers use anecdotal records of poorly known or ‘missing’ species to decide where conservation action should occur, and how urgent that action might be, will support better conservation decisions for those species. Here, we use a Delphi-style process based on expert opinion to assess the largely anecdotal sightings record of the Night Parrot (Pezoporus occidentalis), an endangered species from arid central Australia that underwent a significant decline following the arrival of Europeans. Our results clarify the patterns and possible causes of this decline and subsequent range contraction. We conclude that the species persists in only two broad regions, and is probably extinct throughout much of its former range. Our method is applicable to other poorly known species with a similarly sporadic and largely anecdotal sightings record. This method could be used to clarify the historical and current distribution and status of such species, a critical first step in understanding their conservation requirements.
原文链接:- NSTL
- Taylor & Francis
Amico Guillermo C.Vazquez M. SoledadZamora-Nasca Lucía B.Rodriguez-Cabal Mariano A....
11页查看更多>>摘要：ABSTRACT Predation is the main cause of nest failure among birds. Habitat characteristics play a critical role in affecting nest predation by modifying nest conspicuousness and ease of access to predators. Here, using artificial nests containing a canary egg and a model clay egg we examined and compared nest predation rates and the principal nest predators in three different Patagonian forest stand types. Also, we evaluated how vegetation cover and nest height affected the different nest predators. We found lower nest predation rates in evergreen than deciduous forests, suggesting the forest type as a key factor modulating the risk of nest predation. We identified birds, an arboreal marsupial (Dromiciops gliroides), and mice as the main nest predators in the study area. These nest predators responded differently to the microhabitat conditions around the nest. Predation by birds was mainly related to nests placed closer to the ground, while marsupial nest predation was linked to greater shrub cover and mice showed no response to microhabitat conditions. Together, our results suggest that predation rates result from the interplay between large and small scale habitat characteristics, in addition to predator assemblages. Comparing specific predator-prey interactions is key for understanding the underlying mechanisms influencing nest predation.
原文链接:- NSTL
- Taylor & Francis
Lermite Fran?oiseKark SalitPeneaux ChloeGriffin Andrea S....
6页查看更多>>摘要：ABSTRACT Australian cavity-nesting birds in urban habitats can encounter strong competition for nesting cavities. This results from the shortage of old large hollow-bearing trees in urban areas and because cities often host a suite of alien birds, including cavity-nesters. However, it is unclear whether some behavioural differences are involved with access to nesting cavities. We aimed to examine parental nest attendance, nest disturbance and breeding success in native parrots and the most common invasive urban bird in Australia, the Common Myna, Acridotheres tristis. We installed 78 experimental nest boxes in Newcastle, the second largest city in New South Wales, Australia, to compare native parrots and Mynas. We found that despite occupying nest boxes equally, native parrots had significantly lower breeding success, lost more clutches to hatch failure, exhibited lower levels of parental nest attendance, and encountered higher levels of nest disturbance than the alien Myna. These findings provide important insight into the breeding success of native and alien secondary cavity-nesting birds in cities. Evaluating the effectiveness of urban nest boxes will help guide future research and management aimed at optimising nest box design for maintaining native cavity breeders.
原文链接:- NSTL
- Taylor & Francis
