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Understanding the environmental mechanisms that govern population change is a fundamental objective in ecology. Although the determination of how top-down and bottom-up drivers affect demography is important, it is often equally critical to understand the extent to which, environmental conditions that underpin these drivers fluctuate across time. For example, associations between climate and both food availability and predation risk may suggest the presence of trophic interactions that may influence inferences made from patterns in ecological data. Analytical tools have been developed to account for these correlations, while providing opportunities to ask novel questions regarding how populations change across space and time. Here, we combine two modeling disciplines-path analysis and mark-recapture-recovery models-to explore whether shifts in sea-surface temperatures (SSTs) influenced top-down (entanglement in fishing equipment) or bottom-up (forage fish production) population constraints over 60 years, and the extent to which these covarying processes shaped the survival of a long-lived seabird, the Royal tern. We found that hemispheric trends in SST were associated with variation in the amount of fish harvested along the Atlantic coast of North America and in the Caribbean, whereas reductions in forage fish production were mostly driven by shifts in the amount of fish harvested by commercial fisheries throughout the North Atlantic the year prior. Although the indirect (i.e., stock depletion) and direct (i.e., entanglement) impacts of commercial fishing on Royal tern mortality has declined over the last 60 years, increased SSTs during this time period has resulted in a comparable increase in mortality risk, which disproportionately impacted the survival of the youngest age-classes of Royal terns. Given climate projections for the North Atlantic, our results indicate that threats to Royal tern population persistence in the Mid-Atlantic will most likely be driven by failures to recruit juveniles into the breeding population.

Population declines of disturbance-dependent species due to suppression of natural disturbances are realized across ecosystems. The piping plover (Charadrius melodus; plover), a disturbance-dependent and conservation-reliant shorebird that nests on sandy beaches and barrier islands on the Atlantic Coast, was listed under the United States Endangered Species Act in 1986. In 2012, Hurricane Sandy landed on Fire and Westhampton islands, barrier island nesting sites for plovers in New York, USA. Hurricane Sandy was a natural disturbance in this system, creating abundant nesting habitat. The number of chicks produced by a pair, or a population, is a direct measure of reproductive output, and gaining a better understanding of productivity and chick behavior following large-scale habitat creation may improve plover habitat management and potentially species persistence. We evaluated the effects of landscape features on habitat selection, behavior, and survival of plover broods using logistic regression, generalized linear mixed effects models, and survival models. Plover broods selected flatter sites with less dense vegetation than available at random. Chick foraging rates were highest in moist substrates and were lower in areas of higher nesting plover density. Chick survival was greater for broods that hatched earlier in the breeding season and increased as chicks aged. Generally, providing access to sites with flatter, moist substrates will likely result in higher quality brood rearing habitat on the landscape. Ultimately, vegetation removal and habitat management may be needed to reduce plover nesting density and ensure sufficient habitat, which may in turn improve plover chick survival. Moreover, sustaining natural landscape disturbances such as those resulting from storms, and not taking actions to prevent hurricane-created overwash, will allow these landscape features to persist. U.S. Fish and Wildlife Service [F15AC00393, F13AC00194]; U.S. Army Corps of Engineers [W16R0E30650111] Published version U.S. Fish and Wildlife Service, Grant/Award Numbers: F15AC00393, F13AC00194; U.S. Army Corps of Engineers, Grant/Award Number: W16R0E30650111

Studies of elusive carnivores often rely on passive sampling when investigating either spatial or temporal interactions. However, inference on behavioral mechanisms are usually lacking. We present an analysis that combines previously published spatial co-occurrence estimates and temporal kernel density estimates to explore spatiotemporal interspecific interactions. We do so by deriving a spatiotemporal value (STV) that is a relative measure of potential interaction in both niche dimensions, across a gradient of degradation, for rainforest carnivore pairs in Madagascar. We also use a conceptual framework to provide insight into the potential behavioral mechanisms of habitat selection. Of the six native and three invasive carnivores, we estimate the spatiotemporal interactions for twelve pairings, which range from no spatial/temporal relationship (n = 5) to spatiotemporal aggregation or segregation (n = 7). We visualized these spatiotemporal interactions along a fragmentation gradient and demonstrate that these interactions are not static, as STV overlap increases with increasing anthropogenic disturbance. Of the three invasive carnivores (free-ranging dogs Canis familiaris, cats Felis species, and small Indian civets Viverricula indica) the latter had the highest number of spatial occurrence (n = 4) and spatiotemporal overlap (n = 4) relationships with native carnivores. Our results highlight the potential for increasing direct and indirect interactions between native and invasive species as forest degradation and invasive predators increase. Our approach allows us to better understand adaptive behaviors, plasticity in temporal activity, community assemblage, and to develop targeted conservation strategies to manage ecological communities in rapidly changing ecosystems.

Madagascar is a threatened global biodiversity hotspot and conservation priority, yet we lack broad-scale surveys to assess biodiversity across space and time. To fill this gap, we collated camera trap surveys, capturing species occurrences within Madagascar into a single standardized database. This data set includes nine distinct protected areas of Madagascar and encompasses 13 subprojects, 38 camera arrays, and 1156 sampling units (independent camera site per survey) within two important biodiversity eco-regions: western dry deciduous forest and eastern humid rainforest. Camera surveys were conducted from June 2007 to January 2021. The final data set includes 17 unique families of mammals (Bovidae, Canidae, Cheirogaleidae, Daubentoniidae, Equidae, Eupleridae, Felidae, Hominidae, Indriidae, Lemuridae, Lepilemuridae, Muridae, Nesomyidae, Pteropodidae, Soricidae, Suidae, Tenrecidae) comprising 45 species and 27 unique families of birds (Accipitridae, Acrocephalidae, Alcedinidae, Bernieridae, Brachypteraciidae, Caprimulgidae, Cisticolidae, Columbidae, Coraciidae, Corvidae, Cuculidae, Dicruridae, Mesitornithidae, Monarchidae, Motacillidae, Muscicapidae, Numididae, Phasianidae, Rallidae, Sarothruridae, Strigidae, Sturnidae, Sulidae, Threskiornithidae, Upupidae, Vangidae, Zosteropidae) comprising 58 species. Images were processed and verified by individual project data set creators and camera operation and species tables were then collated. The final product represents the first broad-scale freely available standardized formal faunal database for Madagascar. Data are available through this publication and at DOI: 10.5281/zenodo.5801806. These data will be useful for examining species-level and community-level trends in occurrence across space or time within Madagascar and globally, evaluating native and invasive species dynamics, and will aid in determining species conservation status and planning for at-risk species. There are no copyright restrictions; please cite this paper when using the data for publication.

Habitat selection and its relationship to fitness is a fundamental concept in ecology, but the mechanisms driving this connection are complex and difficult to detect. Despite the difficulties in understanding such intricate relationships, it is imperative that we study habitat selection and its relationship with fitness. We compared habitat selection of least terns (Sternula antillarum) and piping plovers (Charadrius melodus) on the Missouri River (2012–2014) to examine the consequences of those choices on nest and chick survival. We hypothesized that plovers and terns would select habitat that minimized the chance of flooding and predation of eggs, chicks, and adults, but that plovers would also select habitat that would provide foraging habitat for their chicks. We developed an integrated habitat selection model that assessed selection across multiple scales (sandbar and nest scales) and directly modeled the effect of selection on nest and chick survival. In general, the species selected habitat in keeping with our hypotheses, such that predation and flooding, in particular, may have been reduced. Sandbar selection had either a negative or no appreciable effect on nest survival for both species across years. Nest‐site selection in 2012 had a generally positive effect on nest survival and chick survival for both terns and plovers, and this trended toward a negative effect by 2014. This result suggested that early selection decisions appeared to be adaptive, but we speculate that relatively high site fidelity and habitat degradation led to reduced benefit over time. Our results highlight the complex nature of habitat selection and its relationship to fitness., While the connection between species and their habitats is broadly accepted, the connections between habitat and overall fitness often are less well understood. We compared habitat selection of piping plovers and least terns on the Missouri River (2012–2014) to examine the consequences of those choices on nest and chick survival. Our results suggest that early selection decisions were adaptive, but that relatively high site fidelity and habitat degradation led to reduced benefit over time.

The estimation of abundance is fundamental to ecology and conservation but often is difficult or impossible to accomplish reliably. Recent improvements in wildlife cameras and ecological modelling have allowed for improved accuracy in estimates of abundance. In this study, we paired nest captures and high‐definition nest video camera monitoring with modelling for a novel approach to estimate survival and abundance of threatened Piping Plovers Charadrius melodus breeding on Missouri River sandbars. From 2005 to 2014, we captured individuals on nests and uniquely marked them and recaptured previously marked individuals. In 2015–2017, we resighted marked individuals using small, high‐definition video cameras deployed at nests, and counted the number of marked and unmarked breeding individuals associated with nests. We estimated apparent survival and derived estimates of the abundance of breeding individuals and population growth each year using a state‐space Jolly–Seber superpopulation model with the addition of a binomial band ratio model for data collected using nest video cameras. Apparent survival averaged 0.73 ± 0.03 (mean ± sd) throughout the study. The number of breeding individuals varied, with the population increasing from 2012 to 2017 following a major habitat creation event. This study provides one of the few examples of camera data being used to produce demographic parameter and abundance estimates for an avian species. The camera and modelling methods described in this study may be applicable to other avian species in which some portion of the breeding population is uniquely marked.

Understanding factors that influence a species’ distribution and abundance across the annual cycle is required for range-wide conservation. Thousands of imperiled red knots (Calidris cantus rufa) stop on Virginia’s barrier islands each year to replenish fat during spring migration. We investigated the variation in red knot presence and flock size, the effects of prey on this variation, and factors influencing prey abundance on Virginia’s barrier islands. We counted red knots and collected potential prey samples at randomly selected sites from 2007–2018 during a two-week period during early and peak migration. Core samples contained crustaceans (Orders Amphipoda and Calanoida), blue mussels (Mytilus edulis), coquina clams (Donax variabilis), and miscellaneous prey (horseshoe crab eggs (Limulus polyphemus), angel wing clams (Cyrtopleura costata), and other organisms (e.g., insect larvae, snails, worms)). Estimated red knot peak counts in Virginia during 21–27 May were highest in 2012 (11,959) and lowest in 2014 (2,857; 12-year peak migration x¯ = 7,175, SD = 2,869). Red knot and prey numbers varied across sampling periods and substrates (i.e., peat and sand). Red knots generally used sites with more prey. Miscellaneous prey (x¯ = 2401.00/m2, SE = 169.16) influenced red knot presence at a site early in migration, when we only sampled on peat banks. Coquina clams (x¯ = 1383.54/m2, SE = 125.32) and blue mussels (x¯ = 777.91/m2, SE = 259.31) affected red knot presence at a site during peak migration, when we sampled both substrates. Few relationships between prey and red knot flock size existed, suggesting that other unmeasured factors determined red knot numbers at occupied sites. Tide and mean daily water temperature affected prey abundance. Maximizing the diversity, availability, and abundance of prey for red knots on barrier islands requires management that encourages the presence of both sand and peat bank intertidal habitats.

Evaluating population-level responses to conservation action following large-scale disturbance can improve the efficacy of future habitat conservation measures. In October 2012, Hurricane Sandy storm surges cleared vegetation and opened inlets through the barrier islands, Fire Island and Westhampton Island, New York, creating Piping Plover (Charadrius melodus) habitat. Storm effects prompted an island-wide stabilization project, which had the potential to negatively affect novel Piping Plover habitat. Certain sections of Fire Island were designed to create and/or improve habitat (hereafter, restoration areas) to mitigate possible habitat loss or degradation. Since Piping Plovers in New York appear to be habitat-limited, we anticipated positive population growth following habitat creation. From 2013 to 2018, we captured and banded 152 adults and 353 chicks, and monitored 279 nests and 160 broods. We developed an integrated population model to assess demographic processes in response to hurricane created-habitat (2013–2018) and the creation of restoration areas (2015–2018). We observed positive population growth in 3 of 5 yr, and overall growth throughout the period ( = 1.13). Immigration and reproductive output were correlated with population growth (r = 0.92 [95% CI: 0.22 to 0.98] and 0.84 [95% CI: –0.47 to 0.95], respectively). Compared with the rest of the study area, restoration areas had higher chick survival, and lower nest survival and after second-year site fidelity. The result was population growth in restoration areas ( = 1.14) similar to the whole study area. In the short term, restoration areas seemed to mimic natural Piping Plover habitat. Vegetation removal, an important process in renewing natural Piping Plover habitat, likely will be necessary to maintain habitat suitability. Efforts to increase immigration of new breeding adults into the system, and to improve reproductive output, primarily by habitat creation or maintenance, are likely to have the greatest local effect on population growth.LAY SUMMARYDespite being listed under the Endangered Species Act for more than 30 yr, and intensive management, Piping Plovers on the Atlantic Coast have not met population recovery goals across much of their breeding range.Hurricane Sandy increased available nesting habitat (dry sand) by over 150%. Following Hurricane Sandy, we monitored a population of individually marked birds on Fire Island and West Hampton Island, New York, for 6 yr. The area monitored included restored habitat, to evaluate the effectiveness of Piping Plover targeted habitat management.The population increased 90% in the 6 yr following Hurricane Sandy, primarily because of immigrant adults, and local reproductive success. The reproductive output and population growth in restoration areas were similar to the rest of the study area.Overall, Hurricane Sandy habitat creation was positive for this local plover population.Efforts to allow future hurricane storm surges to create habitat, along with continued management, will improve long-term population persistence.

Exotic species may increase or decrease native biodiversity. However, effects of exotic species are often mixed; and indirect pathways and compensatory changes can mask effects. Context-specific assessments of the indirect impacts of exotic species are also needed across multiple spatial scales. Agarophyton vermiculophyllum (previously Gracilaria vermiculophylla), an exotic, invasive macroalga, has established throughout the western hemisphere with reported positive or neutral impacts on biodiversity. Shorebirds are an important group for conservation in areas invaded by A. vermiculophyllum. We assess the impacts of this invader on shorebirds by measuring behavior and habitat selection at spatial scales ranging from algal patches to the entire study region. Birds were considered either flexibleforagers that used diverse foraging techniques, or specialized-foragers that employed fewer, more specialized foraging techniques. Responses were scale dependent, with patterns varying between spatial scales, and between behavior and habitat selection. However, a general pattern of habitat selection emerged wherein flexible-foraging shorebirds preferred A. vermiculophyllum habitat, and for specialized-foragers, habitat selection of A. vermiculophyllum was mixed. Meanwhile, flexible-foraging birds tended to neutrally use or avoid uninvaded habitat, and specialized-foraging birds mostly preferred uninvaded habitat. Shorebird behavioral response was less clear; with flexible-foragers spending less time on bare sediment than expected, the only significant response. Shorebird response to A. vermiculophyllum differed by foraging mode; likely because flexible, opportunistic species more readily use invaded habitat. Increases in A. vermiculophyllum could result in functional homogenization if the bare habitat preferred by specialized-foragers is reduced too greatly. We hypothesize the effect of scale is driven by differences among tidal flats. Thus, tidal flat properties such as sediment grain size and microtopography would determine whether foraging from A. vermiculophyllum was optimal for a shorebird. Specialization and spatial scale are important when assessing the biodiversity conservation impacts of invasive A. vermiculophyllum. National Science FoundationNational Science Foundation (NSF) [DEB-1237733, DEB-1832221, DDGE1315231]; Virginia Society of Ornithology; 4-VA Funding for this work was provided by the National Science Foundation Long-Term Ecological Research Program to the Virginia Coast Reserve LTER under grants: DEB-1237733 (20122018, AFB, SMK, MLP), and DEB-1832221 (20182024, AFB, SMK, MLP). Funding was also provided by the National Science Foundation Graduate Research Fellowship Program under DDGE1315231 (2015-2018, AFB). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author (s) and do not necessarily reflect the views of the National Science Foundation. 4-VA, a collaborative partnership for advancing the Commonwealth of Virginia provided funding for this project (AFB, MLP). And finally the Virginia Society of Ornithology provided funding through the J.J. Murray Student Research Award (AFB). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

The impact of habitat loss on shorebirds may be exacerbated by disturbance from human recreational use, which further reduces the amount of coastal habitat that is functionally available. This can have consequences for the condition of individual birds or for population processes, both of which should be considered in strategies to reduce conflict between shorebirds and recreational users of coastal habitat. Our objectives were to determine the associations between human recreational use, coastal habitat modifications, and Piping Plover (Charadrius melodus) body condition and demography. We monitored banded Piping Plovers throughout their annual cycle to assess variation in body condition, true survival, and site fidelity related to disturbance regimes in 8 geographically proximate, nonbreeding areas along the southeastern Atlantic Coast of North America from 2012 to 2016. Piping Plovers in disturbed sites were 7% lighter than those in less disturbed sites. Additionally, true annual survival was ...

On the Missouri River, the federally endangered interior population of Least Terns (Sternula antillarum) historically nested on sandbars created by sediment deposited during high flows. The Missouri River has been dammed and regulated, however, resulting in decreased flooding and sediment deposition and thus decreased sandbar habitat. In 2011, unusually high water releases created extensive sandbar habitat on the Gavins Point Reach of the Missouri River, and from 2012 to 2014 we examined the post-flood demography of Least Terns. We monitored 382 nests, uniquely marked 672 chicks, and attempted to recapture chicks every 3–4 d until fledging (∼18 d). Daily nest survival was high (0.99 [SE 0.002]), resulting in high mean nest success (0.87 [0.03]). Nest success was highest in 2012 and declined slightly each year. Daily chick survival was 0.96 (0.01), resulting in a mean survival to fledge of 0.44 (0.08). Daily chick survival did not vary by year or by age of chicks but was negatively correlated to h...

Piping Plovers (Charadrius melodus) undertake comparatively short migrations for a shorebird and were not previously thought to congregate in large numbers during migration. Superpopulation size (individuals occurring at the study site during the study period) and stopover duration were estimated for migratory Piping Plovers on South Point, Ocracoke Island, North Carolina, USA, from 3 July–28 October 2016 by integrating a Jolly-Seber model and a binomial model of resighting and count data. We estimated 569 Piping Plovers (95% CI: 502–651) used South Point during fall migration in 2016, approximately 10% of the global population and approximately 15% of the Atlantic Coast population. Stopover duration differed between Piping Plovers that bred on or near our study site (Southern USA, 46 days, SD = 1.7) compared to individuals that bred in the northern area of the breeding range (Atlantic Canada, 41 days, SD = 2.0; New England States, USA, 44 days, SD = 1.8) and the central area of the breeding range (New York and New Jersey, USA, 26 days, SD = 1.4). South Point may be unique in that no other areas are known to host similar numbers of Piping Plovers during fall migration.

— Habitat quality can have a profound effect on the condition and fitness of individual birds and on population demography. We investigated the effects of habitat metrics (invertebrate abundance and habitat type) on the condition (egg mass, adult mass, pre-fledged chick growth rates) of Piping Plovers (Charadrius melodus) nesting on Missouri River sandbars from 2005–2014. The amount of breeding habitat for Piping Plovers was variable throughout our study with more habitat available after flooding occurred in 2011. In addition, increased demographic rates (e.g., reproductive output, hatch year survival, and population growth) were observed in the post-flood period. We hypothesized that the condition of individuals would be related to habitat quality and that increased demographic rates observed on the Missouri River sandbars throughout the post-flood period would, at least in part, be related to increased condition. Egg mass, pre-fledged chick growth rates, and invertebrate prey abundance had simi...

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.

Even in the presence of environmental safeguards, catastrophic accidents related to anthropogenic activities occur that can result in both immediate and chronic impacts on local biota. However, due to the unplanned nature of catastrophes, studies aimed to identify the effects of these accidents on an ecosystem and its inhabitants often have imperfect study designs that are reactive rather than proactive, resulting in methodological and analytical challenges. On 20 April 2010, following an explosion on the Deepwater Horizon oil rig, a well blowout occurred on the seafloor approximately 80 km off the Louisiana coast in the Gulf of Mexico. This blowout resulted in the largest marine oil spill in United States history, which impacted critical migratory stopover and overwintering habitat for many seabird and shorebird species, including species of high conservation concern such as the piping plover ( Charadrius melodus ). Here, we assessed the potential longer-term demographic impacts of the Deepwater Horizon oil spill on piping plovers in a capture-mark-recapture framework. We examined whether a series of demographic processes, including probabilities of remaining at a specific wintering site, over-winter and annual apparent survival, winter stopover duration, and abundance varied among oiled and unoiled habitats. We found that the perceived amount of oiling on land, in water, and on individual birds, as well as numerous demographic processes, were spatially or temporally variable. However, we found little support that piping plover demography was negatively influenced by the magnitude of oil observed at an impacted area, or that demographic rates substantially varied between reference and oil impacted areas. Nor did we find that piping plovers that were observed to be oiled had lower survival probabilities following the DWH oil spill relative to non-oiled individuals from the same winter population. Although we did not find that the Deepwater Horizon oil spill substantially influenced piping plovers, our methods provide an analytical framework to more appropriately address both the near or long-term impacts of an anthropogenic disturbance on a species.

SummaryCamera trap surveys are a non-invasive way to monitor wildlife populations. Although most often used to study medium- and large-sized mammals, camera traps also detect non-target species. These detections provide useful ecological information on little-known species, but such data usually remain unanalysed. We used detections from camera-trapping surveys of native carnivores and small mammals to examine distribution patterns and occupancy trends of little-known ground-dwelling rainforest birds at seven sites across the Masoala-Makira protected area complex in north-eastern Madagascar. We obtained 4,083 detections of 28 bird species over 18,056 trap nights from 200 to 2013. We estimated occupancy across the Masoala-Makira protected area complex (hereafter, landscape occupancy) and annual trends in occupancy at three resurveyed sites for five commonly observed species. Landscape occupancy across Masoala-Makira ranged from 0.75 (SE 0.09; Madagascar Magpie-robinCopsychus albospecularis) to 0.25 (SE 0.06; Scaly Ground-rollerGeobiastes squamiger). Ground-dwelling forest bird occupancy was similar at forest sites that ranged from intact to fully degraded; however, three species were detected less often at sites with high feral cat trap success. Nearly half of all focal species showed declines in annual occupancy probability at one resurveyed site (S02) from 2008 to 2013. The declines in ground-dwelling bird occupancy could have community-wide consequences as birds provide ecosystem services such as seed dispersal and pest regulation. We suggest immediate conservation measures—such as feral cat removal—be implemented to protect ground-dwelling forest birds and other threatened taxa across this landscape.

Surveys across multiple seasons or years are necessary to evaluate the effects of dynamic processes on long-term persistence of wildlife populations, such as effects of exotic species on native species populations. Unfortunately, multi-year surveys are rare, particularly for rainforest carnivore populations, and managers often rely on single-season/year, ‘snapshot’ surveys that produce static estimates of population parameters. Here we provide results using single-species, multi-year occupancy modeling from a six-year survey (2008–2013) of a rainforest carnivore community at a 15 km 2 area study site within the newly established Makira Natural Park, Madagascar. We demonstrate a precipitous decline in the native carnivore community with four of the six native carnivores (falanouc Eupleres goudotii , ring-tailed vontsira Galidia elegans , broad-striped vontsira Galidictis fasciata , and brown-tailed vontsira Salanoia concolor ) decreasing by at least 60% over this six-year period. In addition, we observed two exotic carnivores (small Indian civet Viverricula indica and feral cat Felis species) colonize this study site with Felis species increasing in occupancy from 0 to 0.68 by the final year. Further, we demonstrate how variables associated with human encroachment (i.e. distance to forest edge and nearest village) are most important for explaining these trends in native carnivore extirpation and exotic carnivore colonization. These findings provide additional evidence on the threat posed to native carnivore populations by the expansion of exotic carnivores worldwide. We highlight the striking increase in extirpation, and the factors influencing such changes, for native carnivores. In this manuscript, we point to the limited number of multi-year surveys to evaluate dynamic processes on long-term persistence of native wildlife populations, as well as the lack of exotic carnivore control programs in threatened ecosystems in many developing nations as factors limiting our ability to effectively conserve biodiversity across the globe.

Juvenile prospecting, or exploratory behavior for gleaning information about areas or events, can have profound effects on the selection of future breeding habitat, particularly for birds with high site fidelity whose initial choice of breeding habitat could represent a lifetime investment in fitness. We present data from a 10-yr study of Piping Plovers (Charadrius melodus) on the Missouri River, USA, to determine whether postfledging, hatch-year (HY) prospecting movements inform second-year (SY) nest site choices. First, we compared the home ranges of HY and adult (after-hatch-year; AHY) plovers to investigate whether differences in habitat use existed between HY and AHY plovers. Second, we evaluated the effects of prospecting, nest density, reproductive success, and nesting and foraging habitat availability on SY plover nest site selection. Lastly, we evaluated the potential reproductive benefits of nesting in prospected areas by comparing the nest success and fledging success of SY plovers tha...

In the summer of 2016, we observed a pair of Charadrius melodus (Piping Plover) successfully hatch 2 nests at Fire Island National Seashore and fledge chicks from both broods. Double brooding is rare among Piping Plovers, and fledging chicks from both broods is rarer still. In 2017, we observed male and female siblings, 1 individual hatched from each of the double brood nests, incubating the same clutch of eggs on Westhampton Island. Although double brooding has been noted before in this species, this is the first observation of subsequent inbreeding from such an observation on the Atlantic Coast. This observation is unlikely to be evidence of widespread inbreeding within Piping Plover populations due to little evidence of allelic diversity problems in past genetic studies.

Species listed under the U.S. Endangered Species Act are required to meet stated recovery goals for delisting. These goals often are developed early in the species’ conservation history and may need to be updated or refined as new information becomes available. The Atlantic Coast Piping Plover (Charadrius melodus), which was listed more than 30 yr ago, has not met recovery goals through much of its range. Initial recovery goals included maintaining a reproductive output of 1.5 fledged chicks per pair for 5 yr. This goal was based on modelling that assumed equal survival rates for adults throughout the range, but recent studies suggest that demographic rates may vary with latitude. To investigate latitudinal variation, we developed demographic and population growth estimates for 2 breeding populations of Piping Plovers on the U.S. Atlantic Coast on Fire Island, New York (40.7°N), and on the Outer Banks of North Carolina (35.3°N) in 2013–2017. Breeding success (nest success and pre-fledge chick survival) varied annually but was lower in North Carolina than New York. Average adult true survival in New York (x̅ = 0.73, SE = 0.04) was similar to average survival in North Carolina (x̅ = 0.69, SE = 0.07). Annual post-fledging survival for both sites, however, was variable and often higher than had been previously reported for Atlantic Coast Piping Plovers (0.43–0.66 for New York; 0.31 and 1.0 for North Carolina). While the estimated reproductive output needed for a stationary population for both sites was similar (1.10 chicks per pair for New York, 95% CI: 0.83–1.41; 1.08 for North Carolina, 95% CI: 0.67–1.59), only the New York population achieved or exceeded these values during our study. Our findings suggest that understanding annual and latitudinal demographic variability would be helpful in refining recovery goals.

Density-dependent regulation is a fundamental part of ecological theory and a significant driver of animal demography often through complex feedback loops. We investigated the relationship between flood- and demographically induced fluctuations in density and the breeding propensity and survival of a pioneer species, the piping plover (plover, Charadrius melodus).We captured and marked adult and hatchling plovers on the Gavins Point Reach of the Missouri River in South Dakota and Nebraska, USA, from 2005 to 2014. In 2010 and 2011, historically high water levels and flooding inundated much of the plover’s sandbar nesting habitat on theMissouri River.We developed a Bayesian formulation of a multievent model, or a multistate survival model with state uncertainty to estimate breeding propensity simultaneously with survival. Although plovers are conspicuous, their breeding status can be difficult to establish with certainty, which necessitated the use of uncertain states.With this model, we investigated the effect of sex, habitat availability, river flow, and density (birds/ha nesting habitat) on survival of hatch year and breeding and non-breeding adult plovers. In addition, we estimated the transition rates for these age classes between breeding and nonbreeding states. Non-breeding adults (ɸAHY, n = 0.58 ± 0.06) had lower survival rates than breeding adults (ɸAHY, b = 0.80 ± 0.04), and both breeding survival and breeding propensity decreased with increasing nesting density. Not only did survival and breeding propensity decrease directly at higher nest densities, but survival also was indirectly impacted by increasing the proportion of non-breeding birds with relatively low survival. Thus, plovers were regulated through a complex set of feedback loops, acting as densities increased. Our findings underscore the intricacy of density-dependent regulation and suggest that detailed demographic studies are needed to fully understand these effects. Funding was provided by the U.S. Army Corps of Engineers, the U.S. Fish and Wildlife Service, and Virginia Tech.

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

Honest signaling mechanisms can function to appropriate care to hungry offspring and avoid misdirected care of unrelated offspring. Begging, the behavior by which offspring solicit food and parental care, may be an honest signaling mechanism for need, as well as association of parents and offspring. Roseate terns (Sterna dougallii) exhibit prolonged parental care during the postbreeding staging period, offering an ideal system in which to study begging as an honest signaling mechanism. We conducted focal sampling during two premigratory staging seasons (2014 and 2015) at Cape Cod National Seashore, Massachusetts, USA to determine whether postfledging tern begging behavior was an honest signal for need and parent–offspring association. Based on honest signaling theory, we expected begging behavior to be highest during times of high perceived need, and we expected to see a decrease in begging behavior as young terns became increasingly independent of the care‐giving parent. Also, we predicted that young terns would be more likely to beg at parents than nonparents. We found that young roseate terns begged at their parents more often than nonparents; however, they did not always beg at parents. Model predictions of begging probability showed a linear relationship between begging and time of day and date of season, such that begging increased with time of day and decreased with date of season, respectively. Our results provide evidence for honest parent–offspring interactions and are inconsistent with parent–offspring conflict theory but suggest that begging may play a complex role in postfledging parent–offspring interactions. OPEN RESEARCH BADGES This article has been awarded Open Data, Open materials Badges. All materials and data are publicly accessible via the Open Science Framework at https://doi.org/10.5281/zenodo.2656718.

Seabird demography and spatial distribution outside of the breeding season are poorly understood, and migratory stopover and staging sites represent important energetic bottlenecks during the avian annual cycle. We quantified hatch-year Roseate Tern (Sterna dougallii) weekly residency, weekly recruitment rate into the staging population, and derived weekly staging population growth rate during two postbreeding, premigratory staging seasons (2014 and 2015) at Cape Cod National Seashore, Massachusetts, USA. We also estimated hatch-year tern stopover duration at Cape Cod staging grounds. Tern residency probability at Cape Cod National Seashore during 2014 and 2015 was nearly 1 during the first weeks of the season and decreased steadily over the last 4 weeks to ~0.5 in the final week of the study. Recruitment rates into the staging population, representing the weekly per capita change in hatch-year terns present during the staging season, indicated that most terns arrived on the staging grounds during the first weeks of the staging season (16 July to 19 August). We also identified differences in staging duration between birds from the two breeding regions. Hatch-year terns from the southernmost region spent less time staging at Cape Cod National Seashore than their northern counterparts in both 2014 and 2015. These differences may indicate alternative staging strategies for individuals originating in different regions and possibly reveal differences in resource conditions between these areas, for example, in the availability of ephemeral prey fish.

Between April 2014 and August 2015, we observed 4 Charadrius melodus (Piping Plover) consume small, dead fish, including Anchoa mitchilli (Bay Anchovy) on New York barrier islands. These observations are among the first documented evidence of vertebrate prey in Piping Plover diets. While fish consumption is an opportunistic and infrequent occurrence, this behavior may supplement important nutrients in the diet of Piping Plovers in areas without access to high-quality food resources. Further diet analyses are necessary to understand the importance and relative contribution of fish as a prey resource for endangered Piping Plovers.

Biological invasions can represent important threats to endemic species, including those within the invaders’ food webs. The Asian common toad (Duttaphrynus melanostictus) was introduced to Madagascar in 2011. This introduction presents a potentially dangerous prey item to a relatively naive, highly diverse endemic carnivore fauna. Using a multivariate niche modeling approach (background test), we assessed the predicted niche overlap between D. melanostictus and six endemic carnivores in eastern Madagascar. The overlap between this potential prey and predators was assessed on four environmental niche axes: temperature, precipitation, vegetation cover and elevation. Our results showed a mixture of niche overlap and divergence between D. melanostictus and the six carnivores for environmental axes tested. There was significant overlap with five of the carnivores on temperature and NDVI axes. On the precipitation axis, there was significant overlap between D. melanostictus with two species. Our results suggested that wide-ranging, locally rare carnivores may overlap extensively with D. melanostictus. The six carnivores that inhabit the eastern rainforest of Madagascar will likely share multiple, niche axes with this novel potential prey item. Species that eat the non-native common toad and are susceptible to its toxins are at conservation risk because their populations may not be robust enough to adapt quickly to this threat. We advocate closely monitoring these emerging interactions and suggest a preemptive conservation strategy for carnivores potentially at risk.

Primate populations, including Madagascar’s lemurs, are threatened worldwide and conservationists need accurate population estimates to develop targeted conservation plans. We sought to fill knowledge gaps for three lemur taxa —white-fronted brown lemur (Eulemur albifrons); eastern woolly lemur (Avahi laniger); and Allocebus/Microcebus, a category combining observations of hairy-eared dwarf lemurs (Allocebus trichotis) and mouse lemurs (Microcebus spp.)— in northeastern Madagascar by estimating their density, examining how their encounter rates and densities vary across three different forest types, and monitoring trends in encounter rates and densities at resurveyed sites, using data from surveys at six forest sites over a 4-year period (2010–2013). Landscape density for white-fronted brown lemur, eastern woolly lemur, and Allocebus/Microcebus was 21.5 (SE 3.67), 57.7 (SE 9.17), and 39.1 (SE 9.55) individuals/km2, respectively. There was no difference in density estimates at intact and intermediately degraded forest sites; however, we encountered white-fronted brown lemurs more often in intact forest (1.64 ± SE 0.40 individuals/km) than in intermediately degraded and degraded forest (0.15 ± SE 0.06 and 0.16 ± SE 0.06 individuals/km). In addition, we encountered white-fronted brown lemurs at lower rates in 2013 (0.15 ± SE 0.06 individuals/km) compared to 2010 (0.82 ± SE 0.12 individuals/km) at a resurveyed site. Our findings emphasize that primate researchers must account for variation in how lemur encounter rates and densities differ between intact and degraded forests, and although we observed a decline in white-fronted brown lemur encounter rate at our resurveyed site, we caution that changes in lemur encounter rates may simply reflect lower detection rates rather than lower density. Future research should focus on using conventional distance sampling techniques, which are infrequently used in primate studies, to provide more robust density estimates as a way to accurately assess trends and the effects of anthropogenic pressures on lemur populations.

Despite exceptionally high levels of biodiversity and endemism found in Madagascar, much of its wildlife remains little studied, particularly the carnivore community. The recently described, little-known black forest cat (locally known as “ fitoaty ”) is believed to be restricted to NE Madagascar and has been investigated only through village surveys and anecdotal accounts. From 2008 to 2012, we photographically sampled 7 forest sites with varying degrees of degradation and fragmentation across Makira Natural Park with the goals of: 1) estimating landscape occupancy for fitoaty ( Felis spp.), 2) identifying variables influencing fitoaty occupancy, and 3) comparing fitoaty and feral cat ( Felis spp.) occupancy across the landscape. We observed higher occupancy for fitoaty , minimal co-occurrence between fitoaty and feral cats ( n = 2 sites), and strong divergence in habitat use. We provide the 1st assessment of fitoaty morphology, including comparisons with anecdotal reports, and the 1st population assessment of Madagascar’s exotic cat community with insights into factors associated with carnivore population trends in Madagascar. We suggest the described fitoaty is a phenotypically different form of the feral cat, but additional research is needed. Targeted management plans are needed to diminish the spread and potential negative effects of invasive cats across this important biologically diverse ecoregion.

Primates face many climate and land use change threats, making long-term population monitoring critical to prioritizing conservation efforts. Ground-based line transects are typically conducted to estimate and monitor primate populations. However, transects may be costly and logistically challenging. We sought to test whether low-cost (Propithecus tattersalli) are medium-sized, white lemurs whose creamy colour contrasts against defoliated tree canopies, making them an ideal study species for aerial counts. Quad-copter UAV flights over sifaka groups did not elicit antipredator responses. Photographs demonstrated the ability of UAVs to capture viable imagery of sifakas from approximately 20 m above ground level. Unfortunately, crashes resulting from an inability to programme automated flights over hilly forests cut this pilot study short, highlighting several challenges that remain to implementing UAVs in remote field studies. This study demonstrates that while UAVs offer considerable promise in the future of primate research and conservation, high start-up costs and remote field conditions provide challenging obstacles to first time users hoping to use this exciting new technology. Furthermore, we strongly recommend that thermal cameras be used for direct primate counts with UAVs.

Increasing attention is paid to the effects of human activities, including the use of aircraft, on wildlife. However, responses to visual and auditory stimuli associated with aircraft are highly species- and context-dependent and results of existing studies should not be generalized across species, or even across life stages of the same species. We used digital audio recorders, auto-triggered cameras, and heart rate monitors to study the responses of nesting Wilson's plovers (Charadrius wilsonia) to different types of planes (civilian and military fixed-wing aircraft) and helicopters (civilian and military rotary-wing aircraft) at Cape Lookout National Seashore, North Carolina. We compared vigilance behavior, incubation rate, and heart rate before, during, and after overflights. Wilson's plovers were alert and scanned more during military rotary-wing overflights, and scanned more during both military and civilian fixed-wing overflights than during periods without overflights. Heart rates and incubation rates did not change during any type of overflights. Although we found no direct link between increased vigilance rates and decreased reproductive success, a substantial increase in aircraft traffic at our study site, especially rotary-wing overflights, would merit further investigation. © 2015 The Wildlife Society.

Human populations continue to increase and encroach on remaining natural habitats worldwide, resulting in greater numbers and larger ranges of commensal exotic carnivores such as cats and dogs. This results in increased interactions with native wildlife. In Madagascar, we know relatively little about the effects of domestic and/or feral dogs and cats on native carnivore populations. We investigated spatial interactions by combining photographic sampling across seven sites with two-species co-occurrence modeling to provide the first assessment of the spatial co-occurrence of native and exotic carnivores in Madagascar, including an examination of habitat characteristics that explain these relationships. Our surveys from 2008 to 2013 accumulated 2991 photo-captures of native and exotic carnivores in 8854 trap nights. We found that native and exotic carnivores in rainforest habitat occur together less often than expected and that exotic carnivores may be replacing native carnivores, particularly in forest areas nearest villages. Six of the native carnivores in this study had higher site use in the absence of exotic carnivores and their species interaction factors (SIF) revealed a lack of co-occurrence (e.g. SIF