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Buffer zones, calculated by flight-initiation distance (FID), are often used to reduce anthropogenic disturbances to wildlife, but FID can vary significantly across life-history stages. We examined the behavioral effect of potential natural (gulls and shorebirds) and anthropogenic (pedestrians) disturbance sources to staging roseate (Sterna dougallii) and common tern (S. hirundo) flocks from July to September in 2014 and 2015 at Cape Cod, Massachusetts, USA. We estimated the proportion of the flock exhibiting different responses to potential disturbance sources as a function of distance, flock size, percent roseate terns, and local disturbance rates, using Bayesian zero-and-one inflated beta regression. The proportion of tern flocks responding to the presence of shorebirds by flying was low (0.01 +/- 0.001 [SE]) and did not vary by distance or other covariates, whereas the proportion flying in response to gulls increased as distance decreased, with smaller flocks, and with flocks with a larger proportion of roseate terns being more sensitive to gull presence. Prolonged flight response rapidly increased in probability from 0.0 to as much as 1.0 as distance from pedestrians to the flock decreased from 100 m and was much more likely with smaller flocks. Pedestrian activity levels also had an effect on flock responses; those engaged in active behaviors such as jogging were more likely to cause flushing than those engaged in passive behaviors. Terns seemed to view pedestrians as more of a threat than shorebirds and gulls, even though gulls are frequent kleptoparasites of terns. Pedestrians >120 m from a tern flock generally elicited the same probability of flight response as shorebirds and gulls. We recommend managers maintain anthropogenic disturbance levels at or below the intensity of those from natural sources at sites where recreation and wildlife values are both important. Because staging tern flocks may use a variety of areas within a site, we recommend instituting a 100-m buffer around areas potentially used by staging flocks at Cape Cod, where we studied every location roseate terns are known to use in large numbers. For other sites used by mixed-species tern flocks, we recommend the use of our field and analytical methods to develop appropriate buffer distances that will keep pedestrians far enough away to reduce the likelihood of flight and other non-locomotive anti-predator behaviors. These buffer zones will also benefit other species sensitive to human activity. (c) 2018 The Wildlife Society. ; Cape Cod National Seashore; United States Geological SurveyUnited States Geological Survey; CNY Wildfowlers Association; Edna Baily Sussman Foundation ; The use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the United States Government. The USFWS provided necessary resources to complete the study. M. E. Hake, R. P. Cook, J. J. Taylor, and K. E. Iaquinto provided logistical support and site access. J. L. Correia, J. C. May, S. S. Brady, and P. L. Gallo assisted with data collection. The Cape Cod National Seashore, United States Geological Survey, CNY Wildfowlers Association, and Edna Baily Sussman Foundation provided funding. ; Public domain authored by a U.S. government employee

Identifying the drivers of long-term population change is a key goal of ecological studies. It is complicated by extrinsic and intrinsic factors that may covary with time and/or operate on a time lag. For migratory shorebirds that breed on the barrier islands of eastern North America, populations may be limited by the anthropogenic, climatic, biological environments they encounter throughout the annual cycle. Using three-decades (19892017) of breeding monitoring data collected by the National Park Service at two national seashores in North Carolina (Hatteras and Lookout), we examined the potential drivers of nesting piping plover (Charadrius melodus) and American oystercatcher (Haematopus palliates) populations. Hatteras had five times more annual visitors than Lookout, and our modelling revealed a strong negative relationship between the population size of breeding plovers and human activity and a positive relationship with protection efforts aimed at reducing disturbance. Breeding and wintering climatic conditions, population productivity, and nesting habitat availability showed only weak effects. Thus, a decade-long decline in plover numbers at both seashores starting in the mid-90s reversed as the parks' visitor counts decreased and stricter protections from potential disturbance were implemented. However, the two sympatric populations of oystercatchers showed the opposite population trends from each other at the neighboring seashores, increasing only on Lookout after a hurricane improved habitat and subsequently the reproductive output. Our study suggests a strong relationship between the anthropogenic environment and the population trend of a threatened species and, simultaneously, the important role of stochastic events in shaping populations of long-lived shorebird species. ; Published version ; Public domain authored by a U.S. government employee

Understanding patterns of habitat selection across a species' geographic distribution can be critical for adequately managing populations and planning for habitat loss and related threats. However, studies of habitat selection can be time consuming and expensive over broad spatial scales, and a lack of standardized monitoring targets or methods can impede the generalization of site-based studies. Our objective was to collaborate with natural resource managers to define available nesting habitat for piping plovers (Charadrius melodus) throughout their U.S. Atlantic coast distribution from Maine to North Carolina, with a goal of providing science that could inform habitat management in response to sea-level rise. We characterized a data collection and analysis approach as being effective if it provided low-cost collection of standardized habitat-selection data across the species' breeding range within 1-2 nesting seasons and accurate nesting location predictions. In the method developed, >30 managers and conservation practitioners from government agencies and private organizations used a smartphone application, iPlover, to collect data on landcover characteristics at piping plover nest locations and random points on 83 beaches and barrier islands in 2014 and 2015. We analyzed these data with a Bayesian network that predicted the probability a specific combination of landcover variables would be associated with a nesting site. Although we focused on a shorebird, our approach can be modified for other taxa. Results showed that the Bayesian network performed well in predicting habitat availability and confirmed predicted habitat preferences across the Atlantic coast breeding range of the piping plover. We used the Bayesian network to map areas with a high probability of containing nesting habitat on the Rockaway Peninsula in New York, USA, as an example application. Our approach facilitated the collation of evidence-based information on habitat selection from many locations and sources, which can be used in management and decision-making applications. (c) 2017 The Authors. Wildlife Society Bulletin published by Wiley Periodicals, Inc. on behalf of The Wildlife Society. ; North Atlantic Landscape Conservation Cooperative; U.S. Fish and Wildlife Service; U.S. Department of the Interior Hurricane Sandy recovery program under the Disaster Relief Appropriations Act; U.S. Geological Survey Coastal and Marine Geology Program ; We thank our federal and private collaborators who supervised, participated in, and coordinated field-testing and data collection (listed in Table S1), particularly H. Abouelezz and T. Pearl for providing spatial data for the Breezy Point Unit of the Gateway National Recreation Area. A. Milliken and A. Hecht of the North Atlantic Landscape Conservation Cooperative and U.S. Fish and Wildlife Service, respectively, provided funding and motivation for this research. S. Haefner of the U.S. Geological Survey (USGS) provided code snippets that were used in an alpha version of the iPhone application. We thank N. Booth, M. Schneider, and M. Wernimont of the USGS Office of Water Information and T. Kern and H. Schweizer of the USGS Fort Collins Science Center for their support throughout the development of iPlover. K. Weber of the USGS Woods Hole Coastal and Marine Science Center provided analyses of dune characteristics for the Rockaway Peninsula used in our Geographic Information System analyses. Finally, we appreciate comments on earlier versions of this manuscript made by A. Hecht, N. Ganju, the editorial staff at the Wildlife Society Bulletin, Associate Editor Donahgy Cannon, and 4 anonymous reviewers. This work was supported by the U.S. Department of the Interior Hurricane Sandy recovery program under the Disaster Relief Appropriations Act of 2013, the U.S. Geological Survey Coastal and Marine Geology Program, the U.S. Fish and Wildlife Service, and the North Atlantic Landscape Conservation Cooperative. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Humans have altered nearly every natural disturbance regime on the planet through climate and land-use change, and in many instances, these processes may have interacting effects. For example, projected shifts in temperature and precipitation will likely influence disturbance regimes already affected by anthropogenic fire suppression or river impoundments. Understanding how disturbance-dependent species respond to complex and interacting environmental changes is important for conservation efforts. Using field-based demographic and movement rates, we conducted a metapopulation viability analysis for piping plovers (Charadrius melodus), a threatened disturbance-dependent species, along the Missouri and Platte rivers in the Great Plains of North America. Our aim was to better understand current and projected future metapopulation dynamics given that natural disturbances (flooding or high-flow events) have been greatly reduced by river impoundments and that climate change could further alter the disturbance regime. Although metapopulation abundance has been substantially reduced under the current suppressed disturbance regime (high-flow return interval similar to 20 yr), it could grow if the frequency of high-flow events increases as predicted under likely climate change scenarios. We found that a four-year return interval would maximize metapopulation abundance, and all subpopulations in the metapopulation would act as sources at a return interval of 15 yr or less. Regardless of disturbance frequency, the presence of even a small, stable source subpopulation buffered the metapopulation and sustained a low metapopulation extinction risk. Therefore, climate change could have positive effects in ecosystems where disturbances have been anthropogenically suppressed when climatic shifts move disturbance regimes toward more historical patterns. Furthermore, stable source populations, even if unintentionally maintained through anthropogenic activities, may be critical for the persistence of metapopulations of early-successional species under both suppressed disturbance regimes and disturbance regimes where climate change has further altered disturbance frequency or scope. ; Nebraska Environmental Trust ; Nebraska State Wildlife Grant Program ; Nebraska Wildlife Conservation Fund ; U.S. Army Corps of Engineers ; U.S. Fish and Wildlife Service (USFWS) ; USFWS North Atlantic Landscape Conservation Cooperative ; Virginia Tech ; Funding was provided by the Nebraska Environmental Trust, the Nebraska State Wildlife Grant Program, the Nebraska Wildlife Conservation Fund, the U.S. Army Corps of Engineers, the U.S. Fish and Wildlife Service (USFWS), the USFWS North Atlantic Landscape Conservation Cooperative, and Virginia Tech. We thank C. Aron, K. Brennan, R. Cobb, K. Crane, E. Dowd-Stukel, C. Huber, K. Kreil, C. Kruse, G. Pavelka, G. Wagner, W. Werkmeister, S. Wilson, L. Yager, and cooperators from the National Park Service, U.S. Fish and Wildlife Service, South Dakota Department of Game, Fish, and Parks, Nebraska Game and Parks Commission, and the Missouri River Institute for support throughout the project. We would like to thank sand and gravel mining companies and lakeshore housing development communities for access to property. We acknowledge the tireless efforts of our many technicians from 2005 to 2013. We also thank five anonymous reviewers, T. Simmons, and C. McGowan (USGS) for their comments on earlier drafts of this manuscript. This work was conducted under Institutional Animal Care and Use Committee permits 877 and 14-003, and U.S. Fish and Wildlife Service Threatened and Endangered Species Permits TE070027-0 and TE103272-3. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Wildlife Society Bulletin 41 (2017): 666–677, doi:10.1002/wsb.820. ; Understanding patterns of habitat selection across a species' geographic distribution can be critical for adequately managing populations and planning for habitat loss and related threats. However, studies of habitat selection can be time consuming and expensive over broad spatial scales, and a lack of standardized monitoring targets or methods can impede the generalization of site-based studies. Our objective was to collaborate with natural resource managers to define available nesting habitat for piping plovers (Charadrius melodus) throughout their U.S. Atlantic coast distribution from Maine to North Carolina, with a goal of providing science that could inform habitat management in response to sea-level rise. We characterized a data collection and analysis approach as being effective if it provided low-cost collection of standardized habitat-selection data across the species' breeding range within 1–2 nesting seasons and accurate nesting location predictions. In the method developed, >30 managers and conservation practitioners from government agencies and private organizations used a smartphone application, "iPlover," to collect data on landcover characteristics at piping plover nest locations and random points on 83 beaches and barrier islands in 2014 and 2015. We analyzed these data with a Bayesian network that predicted the probability a specific combination of landcover variables would be associated with a nesting site. Although we focused on a shorebird, our approach can be modified for other taxa. Results showed that the Bayesian network performed well in predicting habitat availability and confirmed predicted habitat preferences across the Atlantic coast breeding range of the piping plover. We used the Bayesian network to map areas with a high probability of containing nesting ...