Suchergebnisse

Knowledge of landscape and regional circumstances where conservation programs are successful on working lands inagricultural production are needed. Convertingmarginal croplands to grasslands using conservation programs such as the United States Department of Agriculture Conservation Reserve Program (CRP) should be beneficial for many grassland-obligate wildlife species; however, addition of CRP grasslands may result indifferent population effects based on regional climate, characteristics of the surrounding landscape, or species planted or established. Within landscapes occupied by lesser prairie-chickens (Tympanuchus pallidicinctus), CRP may provide habitat only for specific life stages and habitat selection for CRP may vary between wet and dry years. Among all study sites, we captured and fitted 280 female lesser prairie-chickens with very high frequency (VHF)- and global positioning system (GPS) transmitters during the spring lekking seasons of 2013-2015 to monitor habitat selection for CRP in regions of varying climate. We also estimated vital rates and habitat selection for 148 individuals, using sites in northwest Kansas, USA. The greatest ecological services of CRP became apparent when examining habitat selection and densities. Nest densities were approximately 3 times greater in CRP grasslands than native working grasslands (i.e., grazed), demonstrating a population-level benefit (CRP = 6.0 nests/10 km(2) +/- 1.29 [ SE], native working grassland = 1.7 nests/10 km(2) +/- 0.62). However, CRP supporting high nest density did not provide brood habitat; 85% of females with broods surviving to 7 days moved their young to other cover types. Regression analyses indicated lesser prairie-chickens were approximately 8 times more likely to use CRP when 5,000-ha landscapes were 70% rather than 20% grassland, indicating variation in the level of ecological services provided by CRP was dependent upon composition of the larger landscape. Further, CRP grasslands were 1.7 times more likely to be used by lesser prairie-chickens in regions receiving 40 cm compared to 70 cm of average annual precipitation and during years of greater drought intensity. Demographic and resource selection analyses revealed that establishing CRP grasslands in northwest Kansas can increase the amount nesting habitat in a region where it may have previously been limited, thereby providing refugia to sustain populations through periods of extreme drought. Nest survival, adult survival during breeding, and nonbreeding season survival did not vary between lesser prairie-chickens that used and did not use CRP grasslands. The finite rate of population growth was also similar for birds using CRP and using only native working grasslands, suggesting that CRP provides habitat similar to that of native working grassland in this region. Overall, lesser prairie-chickens may thrive in landscapes that are a mosaic of native working grassland, CRP grassland, with a minimal amount of cropland, particularly when nesting and brood habitat are in close proximity. (C) 2018 The Wildlife Society ; Kansas Wildlife, Parks, and Tourism (Federal Assistance Grant) [KS W-73-R-3]; United States Department of Agriculture (USDA) Farm Services CRP Monitoring, Assessment, and Evaluation [7, KSCFWRU RWO 62]; USDA Natural Resources Conservation Service, Lesser Prairie-Chicken Initiative ; Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the United States Government. We thank R. D. Rodgers for providing comments and edits on a previous draft of the manuscript. B. Anderson, S. Baker, S. Bard, G. Brinkman, K. Broadfoot, R. Cooper, J. Danner, J. Decker, E. D. Entsminger, R. M. Galvin, N. Gilbert, A. Godar, G. Gould, B. Hardy, S.P. Hoffman, D. Holt, B. M. Irle, T. Karish, A. Klais, H. Kruckman, K. Kuechle, S. J. Lane, E. A. Leipold, J. Letlebo, E. Mangelinckx, L. McCall, A. Nichter, K. Phillips, J. K. Proescholdt, J. Rabon, T. Reed, A. Rhodes, B. E. Ross, D. Spencer, A. M. Steed, A. E. Swicegood, P. Waldron, B. A. Walter, I. Waters, W. J. White, E. Wiens, J. B. Yantachka, and A. Zarazua, provided much needed assistance with data collection. We greatly appreciate the logistic and technical support provided by J. C. Pitman, J. Kramer, M. Mitchener, D. K. Dahlgren, J. A. Prendergast, C. Berens, G. Kramos, A. A. Flanders, and S. Hyberg. Funding for the project was provided by Kansas Wildlife, Parks, and Tourism (Federal Assistance Grant KS W-73-R-3); United States Department of Agriculture (USDA) Farm Services CRP Monitoring, Assessment, and Evaluation (12-IA-MRE CRP TA#7, KSCFWRU RWO 62); and USDA Natural Resources Conservation Service, Lesser Prairie-Chicken Initiative. ; Public domain authored by a U.S. government employee

Agriculture and development have caused landscape change throughout the southwestern Great Plains in the range of the lesser prairie-chicken (Tympanuchus pallidicinctus). Landscape alteration within the lesser prairie-chicken range may contribute to range contraction and population losses through decreases in survival rates. Our objectives were to determine if: (1) landscape configuration (i.e., the spatial arrangement of habitat) or composition (i.e., the amount of habitat), at the study.site scale, affected annual survival of females, (2) relationships exist between landscape context (i.e., landscape configuration and composition) and weekly survival to assess effects of landscape composition and configuration on lesser prairie-chicken populations, and (3) anthropogenic features influenced daily mortality risk. We captured 170 female lesser prairie-chickens and used very-high-frequency and GPS (Global Positioning System) transmitters to track their movement and survival for 2 y. We used known-fate survival models to test if landscape configuration or composition within three sites in Kansas were related to differences in female survival among sites. In addition we tested for relationships between weekly survival and landscape configuration or composition within home ranges. Finally, we used Andersen-Gill models to test the influence of distance to anthropogenic features on daily mortality risk. Differences in survival were evident between sites with differing landscape compositions as annual survival in Northwestern Kansas (S=0.27) was half that of Clark County, Kansas (S=0.56), which corresponded with 41.9% more grassland on the landscape in Clark County; landscape configuration did not measurably differ among sites. Survival was greater for prairie-chickens with home-ranges that had greater patch richness and in areas with 30% crop and 57% grassland. Female lesser prairie-chickens also experienced greater mortality risk closer to fences at patch edges. Further conversion of grassland landscapes occupied by lesser prairie-chickens should be avoided to reduce habitat loss and fragmentation thresholds that could affect survival. We suggest continued encouragement of Conservation Reserve Program enrollment in western areas of the lesser prairie-chicken range to maintain or increase the amount of grassland to increase annual survival. ; Federal Aid in Wildlife Restoration Grant [W-73-R]; US Geological SurveyUnited States Geological Survey; US Dept ofAgriculture (USDA), Natural Resources Conservation Service, Lesser Prairie-Chicken Initiative; Kansas Wildlife, Parks, and Tourism [KS W-73-R-3]; USDA Farm Services CRP Monitoring, Assessment, and Evaluation [7, KSCFWRU RWO 62] ; Wethank J. Pitman, K. Sexton, J. Kramer, M. Mitchener, D. Dahlgren, J. Prendergast, C. Berens, G. Kramos, A. Flanders, and S. Hyberg for their assistance with the project. Research was funded by the Federal Aid in Wildlife Restoration Grant W-73-R; US Geological Survey; US Dept ofAgriculture (USDA), Natural Resources Conservation Service, Lesser Prairie-Chicken Initiative; Kansas Wildlife, Parks, and Tourism (Federal Assistance Grant KS W-73-R-3); USDA Farm Services CRP Monitoring, Assessment, and Evaluation (12-IA-MRE CRP TA#7, KSCFWRU RWO 62). We also thank two anonymous reviewers for reviewing earlier versions of this manuscript. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. ; Public domain authored by a U.S. government employee

Diets during critical brooding and winter periods likely influence the growth of Lesser Prairie-Chicken (Tympanuchus pallidicinctus) populations. During the brooding period, rapidly growing Lesser Prairie-Chicken chicks have high calorie demands and are restricted to foods within immediate surroundings. For adults and juveniles during cold winters, meeting thermoregulatory demands with available food items of limited nutrient content may be challenging. Our objective was to determine the primary animal and plant components of Lesser Prairie-Chicken diets among native prairie, cropland, and Conservation Reserve Program (CRP) fields in Kansas and Colorado, USA, during brooding and winter using a DNA metabarcoding approach. Lesser Prairie-Chicken fecal samples (n = 314) were collected during summer 2014 and winter 2014-2015, DNA was extracted, amplified, and sequenced. A region of the cytochrome oxidase I (COI) gene was sequenced to determine the arthropod component of the diet, and a portion of the trnL intron region was used to determine the plant component. Relying on fecal DNA to quantify dietary composition, as opposed to traditional visual identification of gut contents, revealed a greater proportion of soft-bodied arthropods than previously recorded. Among 80 fecal samples for which threshold arthropod DNA reads were obtained, 35% of the sequences were most likely from Lepidoptera, 26% from Orthoptera, 14% from Araneae, 13% from Hemiptera, and 12% from other orders. Plant sequences from 137 fecal samples were composed of species similar to Ambrosia (27%), followed by species similar to Lactuca or Taraxacum (10%), Medicago (6%), and Triticum (5%). Forbs were the predominant (>50% of reads) plant food consumed during both brood rearing and winter. The importance both of native forbs and of a broad array of arthropods that rely on forbs suggests that disturbance regimes that promote forbs may be crucial in providing food for Lesser Prairie-Chickens in the northern portion of their distribution. ; Kansas Wildlife, Parks, and Tourism [KS W-73-R-3]; USDA Farm Services CRP Monitoring, Assessment, and Evaluation [12-IA-MRE CRP TA#7, KSCFWRU RWO 62]; USDA Natural Resources Conservation Service, Lesser Prairie-Chicken Initiative ; Funding for the project was provided by Kansas Wildlife, Parks, and Tourism (Federal Assistance Grant KS W-73-R-3); USDA Farm Services CRP Monitoring, Assessment, and Evaluation (12-IA-MRE CRP TA#7, KSCFWRU RWO 62); and USDA Natural Resources Conservation Service, Lesser Prairie-Chicken Initiative. ; Public domain authored by a U.S. government employee

For millennia grasslands have provided a myriad of ecosystem services and have been coupled with human resource use. The loss of 46% of grasslands worldwide necessitates the need for conservation that is spatially, temporally, and socioeconomically strategic. In the Southern Great Plains of the United States, conversion of native grasslands to cropland, woody encroachment, and establishment of vertical anthropogenic features have made large intact grasslands rare for lesser prairie-chickens (Tympanuchus pallidicinctus). However, it remains unclear how the spatial distribution of grasslands and anthropogenic features constrain populations and influence conservation. We estimated the distribution of lesser prairie-chickens using data from individuals marked with GPS transmitters in Kansas and Colorado, USA, and empirically derived relationships with anthropogenic structure densities and grassland composition. Our model suggested decreased probability of use in 2-km radius (12.6 km(2)) landscapes that had greater than two vertical features, two oil wells, 8 km of county roads, and 0.15 km of major roads or transmission lines. Predicted probability of use was greatest in 5-km radius landscapes that were 77% grassland. Based on our model predictions, similar to 10% of the current expected lesser prairie-chicken distribution was available as habitat. We used our estimated species distribution to provide spatially explicit prescriptions for CRP enrollment and tree removal in locations most likely to benefit lesser prairie-chickens. Spatially incentivized CRP sign up has the potential to provide 4189 km2 of additional habitat and strategic application of tree removal has the potential to restore 1154 km(2). Tree removal and CRP enrollment are conservation tools that can align with landowner goals and are much more likely to be effective on privately owned working lands. ; Kansas Wildlife, Parks, and Tourism (Federal Assistance Grant) [KS W-73-R-3]; United States Department of Agriculture (USDA) Farm Services CRP Monitoring, Assessment, and Evaluation [12-IA-MRE CRP TA, KSCFWRU RWO 62, 7]; USDA Natural Resources Conservation Service, Lesser Prairie-Chicken Initiative ; We thank Kent Fricke, three anonymous reviewers, and the associate editor for providing reviews that improved the quality of the manuscript. We thank K. Schultz and A. Chappell for capturing and providing GPS data from lesser prairie-chickens captured on the Cimarron National Grasslands. B. Anderson, S. Baker, S. Bard, G. Brinkman, K. Broadfoot, R. Cooper, J. Danner, J. Decker, E. D. Entsminger, R. M. Galvin, N. Gilbert, A. Godar, G. Gould, B. Hardy, S.P. Hoffman, D. Holt, B. M. Irle, T. Karish, A. Klais, H. Kruckman, K. Kuechle, S. J. Lane, E. A. Leipold, J. Letlebo, E. Mangelinckx, L. McCall, A. Nichter, K. Phillips, J. K. Proescholdt, J. Rabon, T. Reed, A. Rhodes, B. E. Ross, D. Spencer, A. M. Steed, A. E. Swicegood, P. Waldron, B. A. Walter, I. Waters, W. J. White, E. Wiens, J. B. Yantachka, and A. Zarazua, provided much needed assistance with data collection. We greatly appreciate the logistic and technical support provided by J. C. Pitman, J. Kramer, M. Mitchener, D. K. Dahlgren, J. A. Prendergast, C. Berens, G. Kramos, and A. A. Flanders. Funding for the project was provided by Kansas Wildlife, Parks, and Tourism (Federal Assistance Grant KS W-73-R-3); United States Department of Agriculture (USDA) Farm Services CRP Monitoring, Assessment, and Evaluation (12-IA-MRE CRP TA#7, KSCFWRU RWO 62); and USDA Natural Resources Conservation Service, Lesser Prairie-Chicken Initiative. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. ; Public domain authored by a U.S. government employee

Marking wild birds is an integral part of many field studies. However, if marks affect the vital rates or behavior of marked individuals, any conclusions reached by a study might be biased relative to the general population. Leg bands have rarely been found to have negative effects on birds and are frequently used to mark individuals. Leg flags, which are larger, heavier, and might produce more drag than bands, are commonly used on shorebirds and can help improve resighting rates. However, no one to date has assessed the possible effects of leg flags on the demographic performance of shorebirds. At seven sites in Arctic Alaska and western Canada, we marked individuals and monitored nest survival of four species of Arctic-breeding shorebirds, including Semipalmated Sandpipers (Calidris pusilla), Western Sandpipers (C. mauri), Red-necked Phalaropes (Phalarope lobatus), and Red Phalaropes (P. fielicarius). We used a daily nest survival model in a Bayesian framework to test for effects of leg flags, relative to birds with only bands, on daily survival rates of 1952 nests. We found no evidence of a difference in nest survival between birds with flags and those with only bands. Our results suggest, therefore, that leg flags have little effect on the nest success of Arctic-breeding sandpipers and phalaropes. Additional studies are needed, however, to evaluate the possible effects of flags on shorebirds that use other habitats and on survival rates of adults and chicks. ; National Fish and Wildlife Foundation [2010-0061-015, 2011-0032-014, 0801.12.032731, 0801.13.041129]; Neotropical Migratory Bird Conservation Act of the U.S. Fish and Wildlife Service [F11AP01040, F12AP00734, F13APO535, 4073, 4102]; Alaska Department of Fish and Game; State Wildlife Grant [T-16]; Arctic National Wildlife Refuge; Bureau of Land Management; Centre for Wildlife Ecology at Simon Fraser University; Environment and Climate Change Canada; Indigenous and Northern Affairs Canada; Kansas State University; Kresge Foundation; Liz Claiborne/Art Ortenberg Foundation; Manomet Center for Conservation Sciences; National Park Service; Murie Science and Learning Center Research Fellowship Program; National Science Foundation (Office of Polar Programs)National Science Foundation (NSF) [ARC-1023396]; National Science Foundation (Doctoral Dissertation Improvement Grant)National Science Foundation (NSF) [1501479]; Natural Resources Canada (Polar Continental Shelf Program); Natural Sciences and Engineering Research Council of Canada (Strategic Grant - Discovery Grants) [357054]; Northern Scientific Training Program (Canadian Polar Commission); U.S. Fish and Wildlife Service (Migratory Bird Management Division, Survey, Monitoring and Assessment Program); U.S. Fish and Wildlife Service (Alaska National Wildlife Refuge System's Challenge Cost Share Program); U.S. Fish and Wildlife Service (Avian Influenza Health and Influenza programs); U.S. Geological Survey (Changing Arctic Ecosystem Initiative, Wildlife Program of the USGS Ecosystem Mission Area); University of Colorado Denver; University of Alaska Fairbanks; University of Missouri Columbia ; Major support for the infrastructure of the Arctic Shorebird Demographics Network was provided by the Arctic Landscape Conservation Cooperative, National Fish and Wildlife Foundation (grants 2010-0061-015, 2011-0032-014, 0801.12.032731, and 0801.13.041129), and Neotropical Migratory Bird Conservation Act of the U.S. Fish and Wildlife Service (grants F11AP01040, F12AP00734, F13APO535, 4073, and 4102). Additional funding for individual sites was provided by Alaska Department of Fish and Game (including State Wildlife Grant T-16), Arctic National Wildlife Refuge, Bureau of Land Management, Centre for Wildlife Ecology at Simon Fraser University, Environment and Climate Change Canada, Indigenous and Northern Affairs Canada, Kansas State University, Kresge Foundation, Liz Claiborne/Art Ortenberg Foundation, Manomet Center for Conservation Sciences, National Park Service (including Murie Science and Learning Center Research Fellowship Program), National Science Foundation (Office of Polar Programs grant ARC-1023396 and Doctoral Dissertation Improvement Grant 1501479), Natural Resources Canada (Polar Continental Shelf Program), Natural Sciences and Engineering Research Council of Canada (Strategic Grant - 357054, Discovery Grants), Northern Scientific Training Program (Canadian Polar Commission), U.S. Fish and Wildlife Service (Migratory Bird Management Division, Survey, Monitoring and Assessment Program, Alaska National Wildlife Refuge System's Challenge Cost Share Program, and Avian Influenza Health and Influenza programs), U.S. Geological Survey (Changing Arctic Ecosystem Initiative, Wildlife Program of the USGS Ecosystem Mission Area), University of Colorado Denver, University of Alaska Fairbanks, and University of Missouri Columbia. We thank local communities and landowners, including the people of the Inuvialuit Settlement Region, North Slope Borough, Ukpeagvik Inupiat Corporation, and Sitnasuak Native Corporation for permitting us to conduct research on their lands. Logistical support was provided by Arctic National Wildlife Refuge (U.S. Fish and Wildlife Service), Barrow Arctic Science Consortium, Cape Krusenstern National Monument (National Park Service), ConocoPhillips Alaska, Inc., Sisualik National Wildlife Refuge (U.S. Fish and Wildlife Service), and Umiaq, LLC. We thank the many field assistants who helped on this project throughout the years, including S. Carvey, T. Donnelly, A. Gottesman, D. Pavlik, and B. Wilkinson for their key roles in field work at the Colville River Delta, and D. Payer for his key role in implementing and overseeing field work at Canning River Delta. J. Lamb, L. Rosen, and B. Ross provided comments on an early draft of the manuscript. Animal handling, marking, and monitoring procedures were approved by animal care and use committees and permitting agencies at Environment and Climate Change Canada, Kansas State University, National Park Service, University of Alaska Fairbanks, U.S. Fish and Wildlife Service, and U.S. Geological Survey - Alaska Science Center. The findings and conclusions in this article are those of the author(s) and do not necessarily represent the views of the U.S. Fish and Wildlife Service. Any use of trade names is for descriptive purposes only and does not imply endorsement by the U.S. Government. ; Public domain authored by a U.S. government employee

Protected area networks facilitate community changes in responses to climate warming. However, the contribution of the site environmental and conservation-oriented characteristics to these responses to climate warming are not well understood. Here, we investigate how composition of non-breeding waterbird communities within the European Union Natura 2000 (N2K) network changes in response to increases in temperature. We measured the community reshuffling of 97 waterbird species in 3,018 N2K sites over 25 years in 26 European countries. We find that N2K sites explicitly designated for protection of waterbirds and with a management plan had faster climate-driven community changes. In contrast, the designation period of the N2K sites was not associated with community adjustment, and sites funded under EU-LIFE had lower climate-driven community changes. Our findings imply that efficient conservation policy that may help waterbird community responses to climate warming is to manage sites that are specifically designated for waterbirds. ; Climate warming is driving changes in species distributions and community composition. Many species have a so-called climatic debt, that is, shifts in range lag behind shifts in temperature isoclines. Inside protected areas (PAs), community changes in response to climate warming can be facilitated by greater colonization rates by warm-dwelling species, but also mitigated by lowering extirpation rates of cold-dwelling species. An evaluation of the relative importance of colonization-extirpation processes is important to inform conservation strategies that aim for both climate debt reduction and species conservation. We assessed the colonization-extirpation dynamics involved in community changes in response to climate inside and outside PAs. To do so, we used 25 years of occurrence data of nonbreeding waterbirds in the western Palearctic (97 species, 7071 sites, 39 countries, 1993–2017). We used a community temperature index (CTI) framework based on species thermal affinities to ...

The Arctic is experiencing rapidly warming conditions, increasing predator abundance, and diminishing population cycles of keystone species such as lemmings. However, it is still not known how many Arctic animals will respond to a changing climate with altered trophic interactions. We studied clutch size, incubation duration and nest survival of 17 taxa of Arctic-breeding shorebirds at 16 field sites over 7years. We predicted that physiological benefits of higher temperatures and earlier snowmelt would increase reproductive effort and nest survival, and we expected increasing predator abundance and decreasing abundance of alternative prey (arvicoline rodents) to have a negative effect on reproduction. Although we observed wide ranges of conditions during our study, we found no effects of covariates on reproductive traits in 12 of 17 taxa. In the remaining taxa, most relationships agreed with our predictions. Earlier snowmelt increased the probability of laying a full clutch from 0.61 to 0.91 for Western Sandpipers, and shortened incubation by 1.42days for arcticola Dunlin and 0.77days for Red Phalaropes. Higher temperatures increased the probability of a full clutch from 0.60 to 0.93 for Western Sandpipers and from 0.76 to 0.97 for Red-necked Phalaropes, and increased daily nest survival rates from 0.9634 to 0.9890 for Semipalmated Sandpipers and 0.9546 to 0.9880 for Western Sandpipers. Higher abundance of predators (foxes) reduced daily nest survival rates only in Western Sandpipers (0.9821-0.9031). In contrast to our predictions, the probability of a full clutch was lowest (0.83) for Semipalmated Sandpipers at moderate abundance of alternative prey, rather than low abundance (0.90). Our findings suggest that in the short-term, climate warming may have neutral or positive effects on the nesting cycle of most Arctic-breeding shorebirds. ; National Fish and Wildlife Foundation [2010-0061-015, 2011-0032-014, 0801.12.032731, 0801.13.041129]; Neotropical Migratory Bird Conservation Act [F11AP01040, F12AP00734, F13APO535, 4073]; Arctic Goose Joint Venture; Arctic National Wildlife Refuge; BP Exploration (Alaska) Inc.; Bureau of Land Management; Canada Fund for InnovationCanada Foundation for Innovation; Canada Research ChairsCanada Research Chairs; Cape Krusenstern National Monument grant; Centre for Wildlife Ecology at Simon Fraser University; Churchill Northern Studies Centre; Cornell University Graduate School Mellon Grant; Ducks Unlimited Canada; Environment and Climate Change Canada; FQRNT (Quebec)FQRNT; Government of Nunavut; Indigenous and Northern Affairs Canada; Kansas State University; Kresge Foundation; Liz Claiborne and Art Ortenberg Foundation; Manomet Center for Conservation Sciences; Mississippi Flyway Council; Murie Science and Learning Center grants; National Fish and Wildlife Foundation; National Park Service; National Science Foundation (Office of Polar Programs Grant) [ARC-1023396]; National Science Foundation (Doctoral Dissertation Improvement Grant)National Science Foundation (NSF) [1110444]; Natural Resources Canada (Polar Continental Shelf Program); Natural Sciences and Engineering Research Council of CanadaNatural Sciences and Engineering Research Council of Canada; Northern Studies Training Program; Selawik National Wildlife Refuge; Trust for Mutual Understanding; Universite du Quebec a Rimouski; University of Alaska Fairbanks; University of Colorado Denver; University of Missouri Columbia; University of Moncton; US Fish and Wildlife Service (Migratory Bird Management Division, Survey, Monitoring and Assessment Program); US Fish and Wildlife Service (Alaska National Wildlife Refuge System's Challenge Cost Share Program); US Fish and Wildlife Service (Avian Influenza Health and Influenza programmes); US Geological Survey (USGS) (Changing Arctic Ecosystem Initiative, Wildlife Program of the USGS Ecosystem Mission Area); W. Garfield Weston Foundation; Alaska Department of Fish and Game ; E.L.W compiled the field data, designed and performed the statistical analyses and wrote the manuscript. B.K.S. assisted with design of analyses and preparation of the manuscript. R.B.L., S.C.B. and H.R.G. led development of standardized field protocols and coordinated field work. B.K.S., R.B.L., S.C.B., H.R.G. and all other authors, who are listed in alphabetical order, designed and conducted the field studies, contributed to interpreting the results and assisted with editing the manuscript. Major support for the ASDN was provided by the National Fish and Wildlife Foundation (grants 2010-0061-015, 2011-0032-014, 0801.12.032731 and 0801.13.041129), the Neotropical Migratory Bird Conservation Act (grants F11AP01040, F12AP00734 and F13APO535) and the Arctic Landscape Conservation Cooperative. Additional funding for participating field sites was provided by: Alaska Department of Fish and Game, Arctic Goose Joint Venture, Arctic National Wildlife Refuge, BP Exploration (Alaska) Inc., Bureau of Land Management, Canada Fund for Innovation, Canada Research Chairs, Cape Krusenstern National Monument grant, Centre for Wildlife Ecology at Simon Fraser University, Churchill Northern Studies Centre, Cornell University Graduate School Mellon Grant, Ducks Unlimited Canada, Environment and Climate Change Canada, FQRNT (Quebec), Government of Nunavut, Indigenous and Northern Affairs Canada, Kansas State University, Kresge Foundation, Liz Claiborne and Art Ortenberg Foundation, Manomet Center for Conservation Sciences, Mississippi Flyway Council, Murie Science and Learning Center grants, National Fish and Wildlife Foundation, National Park Service, National Science Foundation (Office of Polar Programs Grant ARC-1023396 and Doctoral Dissertation Improvement Grant 1110444), Natural Resources Canada (Polar Continental Shelf Program), Natural Sciences and Engineering Research Council of Canada (Discovery Grant and Northern Supplement), Neotropical Migratory Bird Conservation Act (grant 4073), Northern Studies Training Program, Selawik National Wildlife Refuge, Trust for Mutual Understanding, Universite du Quebec a Rimouski, University of Alaska Fairbanks, University of Colorado Denver, University of Missouri Columbia, University of Moncton, US Fish and Wildlife Service (Migratory Bird Management Division, Survey, Monitoring and Assessment Program, Alaska National Wildlife Refuge System's Challenge Cost Share Program and Avian Influenza Health and Influenza programmes), US Geological Survey (USGS) (Changing Arctic Ecosystem Initiative, Wildlife Program of the USGS Ecosystem Mission Area), and the W. Garfield Weston Foundation. Logistical support was provided by Arctic National Wildlife Refuge, Barrow Arctic Science Consortium, BP Exploration (Alaska) Inc., Kinross Gold Corporation, Umiaq LLC, Selawik National Wildlife Refuge (USFWS), ConocoPhillips Alaska Inc., Cape Krusenstern National Monument (National Park Service) and Sirmilik National Park (Parks Canada). We thank local communities and landowners, including the Ukpeagvik Inupiat Corporation, the people of the Inuvialuit Settlement Region, Sitnasuak Native Corporation, the Kuukpik Corporation and the North Slope Borough for permitting us to conduct research on their lands.; Animal handling, marking and monitoring procedures were approved by Environment and Climate Change Canada, Government of Nunavut, Kansas State University, National Park Service, Ontario Ministry of Natural Resources and Forestry, University of Alaska Fairbanks, University of Moncton, US Fish & Wildlife Service and US Geological Survey. All applicable international, national and institutional guidelines for the care and use of animals were followed. We thank A. Tygart for assistance in compiling JAGS for use on the Beocat supercomputer at Kansas State University, D. Payer and S. Freeman for their work at Canning River, and H. Meltofte, P. Battley, B. Ross, J. Sutton, L. Martin and the Sandercock lab for comments on earlier drafts of the manuscript. We thank the many field assistants who were involved in data collection, especially field crew leaders K. Bennet, M. Burrell, J. Cunningham, E. D'Astous, S. Carvey, A. Doll, L. Pirie Dominix, K. Gold, A. Gottesman, K. Grond, P. Herzog, B. Hill, D. Hodgkinson, A. J. Johnson, D. Pavlik, M. Peck, L. Pollock, S. Sapora, B. Schwarz, F. Smith, H. M. Specht, M. VanderHeyden, B. M. Walker and B. Wilkinson. The findings and conclusions in this article are those of the author(s) and do not necessarily represent the views of the US Fish and Wildlife Service. Any use of trade names is for descriptive purposes only and does not imply endorsement by the US Government. ; Public domain authored by a U.S. government employee