Institution
Australasian Wader Studies Group
About: Australasian Wader Studies Group is a based out in . It is known for research contribution in the topics: Population & Flyway. The organization has 9 authors who have published 13 publications receiving 843 citations.
Topics: Population, Flyway, Habitat, Animal ecology, Bay
Papers
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TL;DR: Demographic modelling predicts imminent endangerment and an increased risk of extinction of the subspecies without urgent risk–averse management of the red knot population wintering in Tierra del Fuego, seriously threatening the viability of this subspecies.
Abstract: Most populations of migrant shorebirds around the world are in serious decline, suggesting that vital condition-dependent rates such as fecundity and annual survival are being affected globally. A striking example is the red knot (Calidris canutus rufa) population wintering in Tierra del Fuego, which undertakes marathon 30,000 km hemispheric migrations annually. In spring, migrant birds forage voraciously on horseshoe crab eggs in Delaware Bay in the eastern USA before departing to breed in Arctic polar deserts. From 1997 to 2002 an increasing proportion of knots failed to reach threshold departure masses of 180-200 g, possibly because of later arrival in the Bay and food shortage from concurrent over-harvesting of crabs. Reduced nutrient storage, especially in late-arriving birds, possibly combined with reduced sizes of intestine and liver during refuelling, had severe fitness consequences for adult survival and recruitment of young in 2000-2002. From 1997 to 2002 known survivors in Delaware Bay were heavier at initial capture than birds never seen again, annual survival of adults decreased by 37% between May 2000 and May 2001, and the number of second-year birds in wintering flocks declined by 47%. Population size in Tierra del Fuego declined alarmingly from 51,000 to 27,000 in 2000-2002, seriously threatening the viability of this subspecies. Demographic modelling predicts imminent endangerment and an increased risk of extinction of the subspecies without urgent risk-averse management.
473 citations
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TL;DR: The bottleneck index is developed, a new network metric that positively correlates with the predicted impacts of habitat loss on overall population flow and indicates that migratory species are at greater risk than previously realized.
Abstract: Sea-level rise (SLR) will greatly alter littoral ecosystems, causing habitat change and loss for coastal species. Habitat loss is widely used as a measurement of the risk of extinction, but because many coastal species are migratory, the impact of habitat loss will depend not only on its extent, but also on where it occurs. Here, we develop a novel graph-theoretic approach to measure the vulnerability of a migratory network to the impact of habitat loss from SLR based on population flow through the network. We show that reductions in population flow far exceed the proportion of habitat lost for 10 long-distance migrant shorebirds using the East Asian-Australasian Flyway. We estimate that SLR will inundate 23-40% of intertidal habitat area along their migration routes, but cause a reduction in population flow of up to 72 per cent across the taxa. This magnifying effect was particularly strong for taxa whose migration routes contain bottlenecks-sites through which a large fraction of the population travels. We develop the bottleneck index, a new network metric that positively correlates with the predicted impacts of habitat loss on overall population flow. Our results indicate that migratory species are at greater risk than previously realized.
203 citations
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Max Planck Society1, University of Amsterdam2, University of Debrecen3, University of Veterinary Medicine Vienna4, University of Glasgow5, Kansas State University6, United States Fish and Wildlife Service7, University of Graz8, University of Helsinki9, University of Jyväskylä10, Simon Fraser University11, National Park Service12, Bauman Moscow State Technical University13, Trent University14, Virginia Tech15, College of William & Mary16, Charles University in Prague17, Leibniz Association18, University of Western Australia19, University of Bath20, Université du Québec à Rimouski21, Canadian Wildlife Service22, University of Groningen23, Rutgers University24, Spanish National Research Council25, University of Iceland26, University of Aveiro27, University of Oulu28, Australasian Wader Studies Group29, York University30, Deakin University31, Université de Moncton32, Czech University of Life Sciences Prague33, University of Alaska Fairbanks34, University of Alaska Southeast35, Cornell University36, University of Burgundy37, Babeș-Bolyai University38, Montana State University39, Moscow State University40, Massey University41, Wildlife Conservation Society42, Utrecht University43
TL;DR: The results indicate that even under similar environmental conditions and despite 24-h environmental cues, social synchronization can generate far more diverse behavioural rhythms than expected from studies of individuals in captivity.
Abstract: The behavioural rhythms of organisms are thought to be under strong selection, influenced by the rhythmicity of the environment. Such behavioural rhythms are well studied in isolated individuals under laboratory conditions, but free-living individuals have to temporally synchronize their activities with those of others, including potential mates, competitors, prey and predators. Individuals can temporally segregate their daily activities (for example, prey avoiding predators, subordinates avoiding dominants) or synchronize their activities (for example, group foraging, communal defence, pairs reproducing or caring for offspring). The behavioural rhythms that emerge from such social synchronization and the underlying evolutionary and ecological drivers that shape them remain poorly understood. Here we investigate these rhythms in the context of biparental care, a particularly sensitive phase of social synchronization where pair members potentially compromise their individual rhythms. Using data from 729 nests of 91 populations of 32 biparentally incubating shorebird species, where parents synchronize to achieve continuous coverage of developing eggs, we report remarkable within- and between-species diversity in incubation rhythms. Between species, the median length of one parent's incubation bout varied from 1-19 h, whereas period length-the time in which a parent's probability to incubate cycles once between its highest and lowest value-varied from 6-43 h. The length of incubation bouts was unrelated to variables reflecting energetic demands, but species relying on crypsis (the ability to avoid detection by other animals) had longer incubation bouts than those that are readily visible or who actively protect their nest against predators. Rhythms entrainable to the 24-h light-dark cycle were less prevalent at high latitudes and absent in 18 species. Our results indicate that even under similar environmental conditions and despite 24-h environmental cues, social synchronization can generate far more diverse behavioural rhythms than expected from studies of individuals in captivity. The risk of predation, not the risk of starvation, may be a key factor underlying the diversity in these rhythms.
87 citations
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TL;DR: Results further demonstrate the potential for migratory shorebirds to carry and potentially spread influenza viruses.
Abstract: Shorebirds on their southerly migration from Siberia to Australia, may pass through Asian regions currently experiencing outbreaks of highly pathogenic H5N1 influenza. To test for the presence of avian influenza viruses in migratory shorebirds arriving in Australia during spring 2004, 173 cloacal swabs were collected from six species. Ten swabs were positive for influenza A, with H4N8 viruses detected in five red-necked stints and H11N9 viruses detected in five sharp-tailed sandpipers. No H5N1 viruses were detected. All isolated viruses were non-pathogenic in domestic chickens. These results further demonstrate the potential for migratory shorebirds to carry and potentially spread influenza viruses.
57 citations
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Kansas State University1, United States Fish and Wildlife Service2, Manomet Center for Conservation Sciences3, University of Aveiro4, University of Iceland5, Massey University6, Wildlife Conservation Society7, Université du Québec à Rimouski8, University of Alaska Fairbanks9, University of Burgundy10, Centre national de la recherche scientifique11, University of Groningen12, Simon Fraser University13, Université de Moncton14, Australasian Wader Studies Group15, Cornell University16, University of Oulu17, Trent University18, York University19, Environment Canada20, Aarhus University21, University of Montana22, University of Freiburg23, University of Alaska Anchorage24, United States Geological Survey25
TL;DR: Negative effects of geolocators occurred only for three of the smallest species in the authors' dataset, but were substantial when present and future studies could mitigate impacts of tags by reducing protruding parts and minimizing use of additional markers.
Abstract: Geolocators are useful for tracking movements of long-distance migrants, but potential negative effects on birds have not been well studied. We tested for effects of geolocators (0.8–2.0 g total, representing 0.1–3.9 % of mean body mass) on 16 species of migratory shorebirds, including five species with 2–4 subspecies each for a total of 23 study taxa. Study species spanned a range of body sizes (26–1091 g) and eight genera, and were tagged at 23 breeding and eight nonbreeding sites. We compared breeding performance and return rates of birds with geolocators to control groups while controlling for potential confounding variables. We detected negative effects of tags for three small-bodied species. Geolocators reduced annual return rates for two of 23 taxa: by 63 % for semipalmated sandpipers and by 43 % for the arcticola subspecies of dunlin. High resighting effort for geolocator birds could have masked additional negative effects. Geolocators were more likely to negatively affect return rates if the total mass of geolocators and color markers was 2.5–5.8 % of body mass than if tags were 0.3–2.3 % of body mass. Carrying a geolocator reduced nest success by 42 % for semipalmated sandpipers and tripled the probability of partial clutch failure in semipalmated and western sandpipers. Geolocators mounted perpendicular to the leg on a flag had stronger negative effects on nest success than geolocators mounted parallel to the leg on a band. However, parallel-band geolocators were more likely to reduce return rates and cause injuries to the leg. No effects of geolocators were found on breeding movements or changes in body mass. Among-site variation in geolocator effect size was high, suggesting that local factors were important. Negative effects of geolocators occurred only for three of the smallest species in our dataset, but were substantial when present. Future studies could mitigate impacts of tags by reducing protruding parts and minimizing use of additional markers. Investigators could maximize recovery of tags by strategically deploying geolocators on males, previously marked individuals, and successful breeders, though targeting subsets of a population could bias the resulting migratory movement data in some species.
49 citations
Authors
Showing all 9 results
Name | H-index | Papers | Citations |
---|---|---|---|
Chris J. Hassell | 16 | 37 | 971 |
Clive Minton | 15 | 23 | 1253 |
Ken Gosbell | 14 | 19 | 661 |
Roz Jessop | 4 | 5 | 90 |
Grace Maglio | 1 | 1 | 4 |
K Rogers | 1 | 1 | 16 |
Danny I. Rogers | 1 | 1 | 1 |
Doug Watkins | 1 | 1 | 1 |
Robert Bush | 1 | 2 | 5 |