USGS Science⌕ Search

SEARCH · USGS Science

Results for “Bird Conservation”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15Linked to original sources
USGS2022

Toward scoping reviews of individual bird species

Scoping reviews, in which the literature on a given topic is systematically collated and summarized, aid literature searches and highlight knowledge gaps on a given topic, thus hastening scientific progress and informing conservation efforts. Because much research and conservation is targeted at the species level, ornithology and bird conservation would benefit from scoping reviews of individual species. We present and apply a framework for scoping reviews for three disparate raptor species: California Condor Gymnogyps californianus , Harpy Eagle Harpia harpyja and Gyrfalcon Falco rusticolus . We consulted expert panels to develop appropriate search strings and lists of essential literature, i.e. ‘benchmark articles’. We searched Web of Science, Scopus and Google Scholar. Searches for California Condor, Harpy Eagle and Gyrfalcon returned 268, 138 and 343 articles, respectively, that discuss, review or collect empirical data for the focal species. Our searches returned all benchmark articles identified by species experts, indicating that the searches captured the most important work on each species. We coded each study according to the topic addressed, country and month in which data were collected. We also coded threats, stresses and conservation actions addressed by studies, following definitions used by the International Union for the Conservation of Nature (IUCN) during Red List assessments. Literature summaries for each species include the number of studies addressing certain topics, monthly timing of research and global maps of research focus. Our coding scheme revealed important knowledge gaps for each species. Effects of conservation actions on wild individuals were less studied for California Condors. Harpy Eagles were less studied outside of Brazil and Panama, and Gyrfalcons were less studied outside of their breeding season. Scoping reviews of the world's bird species would help to identify critical knowledge gaps, thereby aiding the global effort to assuage the sixth mass extinction.

Ibis↗
USGS2026

Evaluating interactive effects of the Conservation Reserve Program and wind energy infrastructure on grassland bird abundance in the United States

The extent of grasslands has contracted globally, leading to significant declines in grassland-obligate species, including birds. Grassland birds are threatened by multiple factors, including grassland conversion to cropland, and development, including energy infrastructure. In the USA, the federal Conservation Reserve Program (CRP) provides financial incentives for agricultural landowners to convert marginal cropland to vegetative covers, including grassland, making it a key approach to recovering grasslands. However, given the high percentage of wind turbines near Conservation Reserve Program land, it is critical to determine if wind energy and the Conservation Reserve Program interact to affect grassland birds. We used generalized additive models and community science eBird data to assess the interactive effects of wind and the Conservation Reserve Program on the abundances of 27 grassland-obligate bird species across their breeding ranges in the continental US. We found associations between bird relative abundances and interactions involving wind and Conservation Reserve Program variables, suggesting that wind energy development near Conservation Reserve Program fields could dampen the benefits of the Conservation Reserve Program for some species. These results indicate that decisions about where to install wind energy infrastructure that incorporate information about the presence of Conservation Reserve Program land may reduce the adverse effects of wind energy on grassland birds. This study provides information that can help maximize the benefits of the Conservation Reserve Program while allowing for environmentally friendly development of renewable energy.

contiguous United States↗
USGS2022

Avian community response to a novel environment: Commercial forestry in the Campos grasslands of South America

Establishing commercial tree plantations in native grassland ecosystems introduces a different structural and functional vegetation cover type, with expected implications for biodiversity. To better understand biodiversity responses to afforestation, we conducted a resource-use study with birds as a focal group, during the 2013–2014 breeding season in the Northern Campos grasslands of Uruguay. We sampled birds in native environments and plantations of loblolly pine ( Pinus taeda ) and flooded gum ( Eucalyptus grandis ) at different rotation stages. We recorded 103 species during 1,573 visits (10-min, 50-meter radius point counts) to 570 stratified sampling units. Native grasslands and forests exhibited greater diversity and had greater variability in species composition than structurally homogeneous plantations. Avian communities in plantations had distinct species combinations and relative abundances not found in native conditions. Avian communities in older plantations were more similar to native forests while those of newly-planted stands were more like grasslands. However, plantations were dominated by habitat generalists and some forest-dependent species, with negligible use by grassland specialist birds. Our results suggest the best conservation opportunities for grassland-dependent birds in afforested systems of the Campos of Uruguay may depend on diverse landscape-level measures rather than stand-level management practices. Albeit our research constituted a comprehensive assessment of bird taxonomic alpha and beta diversity, research on complementary diversity facets and multi-scale resource selection and demographic studies are needed to better understand the fitness implications for conserving and managing grassland birds in afforested landscapes.

Campos grasslands↗
USGS2014

Geographic coincidence of richness, mass, conservation value, and response to climate of U.S. land birds

Distributional patterns across the United States of five avian community breeding-season characteristics—community biomass, richness, constituent species' vulnerability to extirpation, percentage of constituent species' global abundance present in the community (conservation index, CI), and the community's position along the ecological gradient underlying species composition (principal curve ordination score, PC)—were described, their covariation was analyzed, and projected effects of climate change on the characteristics and their covariation were modeled. Higher values of biomass, richness, and CI were generally preferred from a conservation perspective. However, higher values of these characteristics often did not coincide geographically; thus regions of the United States would differ in their value for conservation depending on which characteristic was chosen for setting conservation priorities. For instance, correlation patterns between characteristics differed among Landscape Conservation Cooperatives. Among the five characteristics, community richness and the ecological gradient underlying community composition (PC) had the highest correlations with longitude, with richness declining from east to west across the contiguous United States. The ecological gradient underlying composition exhibited a demarcation near the 100th meridian, separating the contiguous United States grossly into two similar-sized avian ecological provinces. The combined score (CS), a measure of species' threat of decline or extirpation, exhibited the strongest latitudinal pattern, declining from south to north. Over ∼75% of the lower United States, projected changes in June temperature and precipitation to year 2080 were associated with decreased averaged values of richness, biomass, and CI, implying decreased conservation value for birds. The two ecological provinces demarcated near the 100th meridian diverged from each other, with projected changes in June temperatures and precipitation from the year 2000 to 2080 suggesting increased ecological dissimilarity between the eastern and western halves of the lower United States with changing climate. Anticipated climate-related changes in the five characteristics by 2080 were more weakly correlated with latitude or longitude then the responses themselves, indicating less distinct geographic patterns of characteristic change than in the characteristics themselves. Climate changes projected for 2080 included geographic shifts in avian biomass, CS, and PC values, a moderate overall decline in CI, and general decline in species richness per site.

Ecological Applications↗
USGS2018

Public views of wetlands and waterfowl conservation in the United States—Results of a survey to inform the 2018 update of the North American Waterfowl Management Plan

Executive Summary This report provides information from a general public survey conducted in early 2017 to help inform the North American Waterfowl Management Plan (NAWMP) 2018 update. This report is intended for use by the NAWMP advisory committees and anyone interested in the human dimensions of wetlands and waterfowl management. A mail-out survey was sent to 5,000 addresses in the United States, which were selected randomly in proportion to the population of each State. A total of 1,030 completed surveys representing 49 States were returned, resulting in a 23 percent overall response rate. When comparing the demographics of the respondents to the U.S. census data, this sample overrepresented people who are male, older, highly educated, and white. Data were weighted on gender and age to make the results more representative of the overall U.S. population. Additionally, this sample had higher participation rates in all wildlife-related recreation activities than has been found in previous studies; this indicates there may have been selection bias, with people interested in nature-related topics more likely to complete the survey. Therefore, results likely represent a segment of the U.S. public that is more oriented toward and aware of wildlife and conservation issues than the general public as a whole. Because of this bias, responses for each question were also broken down by recreationist type (hunters, anglers, wildlife viewers, and no wildlife-related recreation). Additionally, responses for each question were split by administrative flyway (Atlantic, Central, Mississippi, Pacific) and residency (urban, urban cluster, rural) to better understand the different groups. Most respondents knew of wetlands in their local area or community, and more than half had visited wetlands in the previous 12 months. Of those who had visited wetlands, the most common reasons were for walking/hiking/biking and enjoying nature/picnicking. In addition, this sample was very concerned about the reduction or loss of ecosystem services resulting from wetlands degradation or loss. A majority of respondents were somewhat or very concerned about 9 out of 10 wetlands benefits, with hunting opportunities being the only benefit the majority of people were not concerned about. People were the most concerned about clean water, clean air, and providing a home for wildlife. In contrast, people were least concerned about hunting opportunities and wetlands providing scenic places for inspiration or spiritual renewal. Communication about wetlands that focuses on habitat, clean air, and clean water may resonate with the widest variety of people. However, if communication is targeted toward wildlife-related recreationists, including more information about the recreation benefits of wetlands and emphasizing habitat benefits may be the most effective. Many people reported having participated in conservation behaviors in the last year. The most popular activity was making the yard more desirable to wildlife, with more than three-fourths of respondents participating, followed by donating money to support wildlife/habitat conservation and talking to others in their community about conservation issues. There was lower participation in conservation behavior specifically related to wetlands and waterfowl, with two-fifths of respondents voting for candidates or ballot issues to support wetlands/waterfowl conservation and one-third advocating for political action to conserve wetlands/waterfowl. In order to better understand how to reach out to the public on nature-related topics, preferences in information channels and trust in information sources were explored. Respondents were mostly likely to want to receive their information through personal experience, by reading or accessing online content, and through watching visual media online. People were least likely to want to receive information through listening to recorded audio media, attending educational opportunities, and listening to live audio media. These results emphasize the importance of having content available online in an easily accessible and appealing format. Visual media in particular seems to be preferred across a wide variety of people. Additionally, people had the highest trust in scientific organizations, universities/educational organizations, and friends/family/neighbors/colleagues. The least trusted sources were national media/news, religious organizations, and local media/news. Urban respondents had higher trust levels overall, particularly for the government. Hunters and those in rural areas had lower levels of trust in the government but higher trust in family/friends. In this sample, few respondents reported hunting waterfowl (5 percent) or hunting other game (16 percent) in the last year. Additionally, few respondents said they were very or somewhat likely to hunt waterfowl in the following 12 months. Even after considering that self-selection bias would make it more likely for hunters to respond to the survey, the relatively small number of respondents who identified as hunters reinforces that engagement of other wildlife-related recreationists is critical to meeting the third goal of the NAWMP 2012 revision—to increase numbers of wetlands/waterfowl conservationists. Many people also had negative perceptions of hunting. Half of the respondents stated that hunting would be unpleasant, and two-fifths believed hunting would be boring. In contrast, people had more favorable attitudes toward birdwatching, with only one-sixth saying it would be unpleasant and less than one-third saying it would be boring. A majority of respondents thought they could easily go hunting or birdwatching in the following 12 months. Overall, people had much more positive views toward birdwatching and expressed fewer barriers to participating in it. When asked what would prevent them from hunting, the most frequently stated reasons were moral opposition, no interest, personal health, and time constraints; for birdwatching, the most popular responses were nothing, no interest, and time constraints. These responses indicate it may be beneficial to move beyond hunting and find ways for other groups, such as birdwatchers, to play a more active role in conservation. Although not many people hunted and many people tended to have negative attitudes toward hunting, over three-fourths of people said they knew a hunter. Given that wildlife viewers, those who did not participate in wildlife-related recreation, and urban residents tended to have negative attitudes toward hunting and (or) were not interested in participating, attempting to recruit them to participate in hunting may not be effective. However, given how many people across all groups knew a hunter and the relatively high levels of trust people had in their friends/family, hunters may be effective ambassadors for promoting waterfowl and wetlands conservation among nonhunters. Additionally, because people had less preference for viewing waterfowl and other game birds compared to their preference for seeing hummingbirds and birds of prey, conservation efforts that extend beyond waterfowl and include other species that benefit from wetlands may have more appeal to a broader range of people.

Open-File Report↗
USGS2018

Effects of early-successional shrubland management on breeding wood thrush populations

In forested landscapes, creation of habitat for early-successional shrubland birds is controversial because of perceived conflicts with the conservation of mature-forest birds. Nonetheless, many mature-forest birds, especially fledglings, readily use early-successional stands during the post-breeding period. This suggests that for mature-forest birds, creating habitat for early-successional birds could involve a tradeoff: reduced abundance and nest survival due to the loss of nesting habitat versus enhanced fledgling survival in early-successional stands. Our research addressed the effects of the creation of early-successional habitat for shrubland birds on wood thrushes ( Hylocichla mustelina ) in western Massachusetts, USA. We compared wood thrush abundance, nest success, fecundity, and post-fledging survival in landscapes with high (∼20%) or low (∼1%) cover of early-successional stands suitable for shrubland birds. We found no differences in nest success, fecundity, and post-fledging survival between the 2 types of landscapes. Abundance of breeders, however, was significantly greater on the sites with high cover of early-successional habitat. We conclude that in forested landscapes, creation of early-successional habitat at levels recommended for the conservation of shrubland birds is compatible with viable wood thrush populations. © 2018 The Wildlife Society.

Massachusetts↗
USGS2025

Same view through a different lens: Comparing population trends for North American birds using eBird and the Breeding Bird Survey

Confidently estimating population trends is of vital importance for a wide range of ecological, conservation, and management applications. North America has 2 major data sources for estimating population trends of breeding birds—the North American Breeding Bird Survey (BBS) and the global participatory science project eBird. Because the surveys differ in protocols, coverage, and data analysis, their trend estimates are expected to vary in magnitude, direction, and/or precision for at least some species and regions. Here, we compare independently derived estimates of population change between 2012 and 2022 for every combination of species and bird conservation region (BCR) covered by both surveys ( n = 5,577 combinations) as well as aggregated across entire ranges or within the U.S. or Canada. Uncertainty was substantial for both surveys, though more prevalent for BBS (81% of credibility intervals for estimates included zero) than eBird (34% of confidence intervals overlapped zero). We found agreement of trend directions between the 2 surveys. Only 1.3% of estimated trends were significant in opposite directions between the 2 surveys for all species/BCR combinations, with the median difference in trend magnitude being –0.02% (BBS minus eBird trend). Correlations between the 2 were strongest for estimates that were graded as being high credibility compared to estimates judged to have medium or low credibility. Both surveys were subject to species, taxonomic, and regional effects that influenced agreement. Overall, we show where trend estimates derived from BBS and eBird agree, explore where they diverge, present several comparisons to assist in interpreting results from both surveys, and inform efforts to integrate information from each.

Ornithological Applications↗
USGS2008

Coordinating across scales: Building a regional marsh bird monitoring program from national and state Initiatives

Salt marsh breeding bird populations (rails, bitterns, sparrows, etc.) in eastern North America are high conservation priorities in need of site specific and regional monitoring designed to detect population changes over time. The present status and trends of these species are unknown but anecdotal evidence of declines in many of the species has raised conservation concerns. Most of these species are listed as conservation priorities on comprehensive wildlife plans throughout the eastern U.S. National Wildlife Refuges, National Park Service units, and other wildlife conservation areas provide important salt marsh habitat. To meet management needs for these areas, and to assist regional conservation planning, survey designs are being developed to estimate abundance and population trends for these breeding bird species. The primary purpose of this project is to develop a hierarchical sampling frame for salt marsh birds in Bird Conservation Region (BCR) 30 that will provide the ability to estimate species population abundances on 1) specific sites (i.e. National Parks and National Wildlife Refuges), 2) within states or regions, and 3) within BCR 30. The entire breeding range of Saltmarsh Sharp-tailed and Coastal Plain Swamp sparrows are within BCR 30, providing an opportunity to detect population trends within the entire breeding ranges of two priority species.

Book chapter↗
USGS2017

Small high-definition video cameras as a tool to resight uniquely marked Interior Least Terns (Sternula antillarum athalassos)

Many bird species of conservation concern have behavioral or morphological traits that make it difficult for researchers to determine if the birds have been uniquely marked. Those traits can also increase the difficulty for researchers to decipher those markers. As a result, it is a priority for field biologists to develop time- and cost-efficient methods to resight uniquely marked individuals, especially when efforts are spread across multiple States and study areas. The Interior Least Tern ( Sternula antillarum athalassos ) is one such difficult-to-resight species; its tendency to mob perceived threats, such as observing researchers, makes resighting marked individuals difficult without physical recapture. During 2015, uniquely marked adult Interior Least Terns were resighted and identified by small, inexpensive, high-definition portable video cameras deployed for 29-min periods adjacent to nests. Interior Least Tern individuals were uniquely identified 84% (n = 277) of the time. This method also provided the ability to link individually marked adults to a specific nest, which can aid in generational studies and understanding heritability for difficult-to-resight species. Mark-recapture studies on such species may be prone to sparse encounter data that can result in imprecise or biased demographic estimates and ultimately flawed inferences. High-definition video cameras may prove to be a robust method for generating reliable demographic estimates.

Nebraska, North Dakota, South Dakota↗
USGS2028

Migration ecology and stopover population size of Red Knots Calidris canutus rufa at Mingan Archipelago after exiting the breeding grounds

Populations of migratory birds present unique conservation challenges given the often vast distances separating critical resources throughout the annual cycle. Migration areas close to the breeding grounds represent a link between two key stages of the annual cycle, and understanding migration ecology as birds exit the breeding grounds may be particularly informative for successful conservation. We studied migration phenology and stopover ecology of an endangered subspecies of the Red Knot Calidris canutus rufa at a migration area relatively close to its breeding range. Using mark-recapture/resight data and a Jolly-Seber model for open populations, we described the arrival and departure schedules, stopover duration, and passage population size at the Mingan Archipelago, Quebec, Canada. Red Knots arrived at the study area in two distinct waves of birds separated by approximately 22 days. Nearly 30% of the passage population arrived in the first wave of arrivals during 15–18 July, and approximately 22% arrived in a second wave during 8–11 August. The sex-ratio in the stopover population at the time of the first wave was slightly skewed toward females, whereas the second wave was heavily skewed toward males. Because males remain on the breeding grounds to care for young, this may reflect successful breeding in the year of our study. The estimated stopover duration (population mean) was 11 days (95% credible interval: 10.3–11.7 days), but stopover persistence was variable throughout the season. We estimated a passage population size of 9,450 birds (8,355–10,710), a minimum estimate for reasons related to the duration of our sampling. Mingan Archipelago is thus an important migration area for this endangered subspecies and could be a priority in conservation planning. Our results also emphasize the advantages of mark-recapture/resight approaches for estimating migration phenology and stopover persistence.

Quebec↗
USGS2025

Small waterbodies of large conservation concern: Towards an integrated approach to more accurately measuring surface water dynamics

Millions of small waterbodies are dispersed throughout the middle of the North American continent, and billions of dollars have been invested to conserve, restore, and manage these waterbodies in the 20th and 21st centuries. Small waterbody conservation has been supported by different stakeholders aiming at improving water quality, enhancing floodwater storage, and supporting migratory bird breeding habitat. Conservation agencies are using hydrological and biological monitoring, modeling, and mapping to adaptively manage small waterbodies in the face of stressors such as invasive species and climate change. As remote sensing estimates of small waterbody surface water extent have become easier to access, understanding the capabilities and limitations of using remote sensing, especially in areas lacking surface water monitoring, is important for conservation decision making. Here, we used in situ monitoring and process-based hydrological modeling to explore remote sensing accuracy, especially related to waterbody size, emergent aquatic vegetation cover, and climatic conditions. Overall, we found that the accuracy of satellite and aerial imagery surface water mapping approaches vastly decreased for waterbodies smaller than 2 ha. We also found emergent vegetation could be masking surface water in waterbodies larger than 2 ha and that accuracy of some remote sensing estimates may decrease during wetter climatic periods. These results indicate that sensors commonly used for surface water applications alone may not be able to accurately detect small waterbody surface water, which supports the need for combining monitoring and modeling to understand how small waterbodies may respond to future changes in climate and land use.

Minnesota↗
USGS2005

Hierarchical models and Bayesian analysis of bird survey information

Summary of bird survey information is a critical component of conservation activities, but often our summaries rely on statistical methods that do not accommodate the limitations of the information. Prioritization of species requires ranking and analysis of species by magnitude of population trend, but often magnitude of trend is a misleading measure of actual decline when trend is poorly estimated. Aggregation of population information among regions is also complicated by varying quality of estimates among regions. Hierarchical models provide a reasonable means of accommodating concerns about aggregation and ranking of quantities of varying precision. In these models the need to consider multiple scales is accommodated by placing distributional assumptions on collections of parameters. For collections of species trends, this allows probability statements to be made about the collections of species-specific parameters, rather than about the estimates. We define and illustrate hierarchical models for two commonly encountered situations in bird conservation: (1) Estimating attributes of collections of species estimates, including ranking of trends, estimating number of species with increasing populations, and assessing population stability with regard to predefined trend magnitudes; and (2) estimation of regional population change, aggregating information from bird surveys over strata. User-friendly computer software makes hierarchical models readily accessible to scientists.

Book chapter↗
USGS2021

Foraging behavior in a generalist snake (brown treesnake, Boiga irregularis) with implications for avian reintroduction and recovery

Broad foraging classifications, such as generalist or specialist forager, are generally beneficial for population management in defining expectations of typical behavior. However, better understanding as to how individual variance in behavior interfaces with management actions, such as control of an invasive predator (such as brown treesnakes; Boiga irregularis ) responsible for ecological collapse of a taxonomic group (birds), may affect conservation goals. In the context of predator control, better understanding of foraging ecology and prey specificity helps to ensure that food-based control programs are removing the target individuals. We sought to quantify whether differences in a dietary generalist snake species was measurable during captive trials using mice or birds as the prey choice. We presented snakes with prey choices that could be or are integrated with tools deployed by managers for control to directly relate choice or preference to management action. We collected wild brown treesnakes and classified them as bird eaters or of unknown diet based on food items present in their digestive tract at the time of capture. In experimental tests, we used live birds and live mice in traps, as well as bird and mouse carrion presented on platforms, to measure interest, take rates, and repeatability (preference) by snakes. We found that all individuals spent more time investigating live birds than they did mice, independent of dietary history, which resulted in twice as many snakes being captured in traps with live birds compared to live mice. There was, however, roughly equal interest in mouse and bird carrion. Within individuals, there was evidence for decreased interest in mouse carrion, if individuals ate birds in the wild. Choice of carrion type was repeatable across trials, suggesting preference may exist. Overall, interest in both live mice and mouse carrion was greatest for medium-bodied snakes, while interest in bird carrion was independent of snake size. Our results indicate that management of invasive predators, including reptiles, may more rapidly achieve conservation targets when managers consider individual heterogeneity in behavior. For brown treesnakes more interested in birds, managers may remove more snakes if they use avian food lures; increased removal of avian specialists may facilitate avian recovery.

Applied Animal Behavior Science↗
USGS2000

Population and habitat viability assessments for Golden-cheeked Warblers and Black-capped Vireos: Usefulness to Partners in Flight Conservation Planning

Golden-cheeked Warblers and Black-capped Vireos are Neotropical migratory birds that are federally listed as endangered. Recovery plans for both species advise the use of viability modeling as a tool for setting specific recovery and management targets. Population and Habitat Viability Assessment workshops were conducted to develop population targets and conservation recommendations for these species. Results of the workshops were based on modeling demographic and environmental factors, as well as discussions of management issues, management options, and public outreach strategies. The approach is intended to be iterative, and to be tracked by research and monitoring efforts. This paper discusses the consensus-building workshop process and how the approach could be useful to Partners in Flight. Population and Habitat Viability Assessments (PHVA) were used to develop population targets and conservation recommendations for Golden-cheeked Warblers (Dendroica chrysoparia) and Black-capped Vireos (Vireo atricapillus). This paper explains what PHVAs are, discusses how they are conducted, describes the general results that are produced, and suggests how Partners in Flight (PIF) might use a similar process for bird conservation planning. Detailed results of the assessments are not discussed here; however they can be found elsewhere (U. S. Fish and Wildlife Service 1996a, U. S. Fish and Wildlife Service 1996b). PHVAs were considered for Golden-cheeked Warblers and Black-capped Vireos because they are controversial, endangered species, and the species? recovery plans list PHVAs as tools to develop recovery recommendations. The U. S. Fish and Wildlife Service (USFWS) realized that the data needed to perform PHVAs for these species is limited, but that various conservation efforts, such as the Balcones Canyonlands Conservation Plan and other endeavors, were proceeding without benefit of the biological summarization and guidance that a PHVA could provide.

Book chapter↗
USGS2006

Conceptual ecological model for management of breeding grassland birds in the Mid-Atlantic Region

The status of grassland birds has become an increasingly important conservation issue. These species exhibit the most consistent population declines of any group of North American birds during the past 40 years. Anecdotal evidence suggests these declines have been occurring for nearly a century (Peterjohn and Sauer 1999). While the widespread conversion of grasslands into other habitats contributed to these declining populations, other factors such as habitat fragmentation and mowing regimes are also implicated (Vickery et al. 1999a). This plight of grassland birds has heightened awareness of the need for concerted conservation actions to reverse these seriously declining population trends. The National Park Service (NPS) is positioned to potentially contribute to grassland bird conservation in the Mid-Atlantic Region. The NPS maintains a number of historic sites and former battlefields that are managed for their cultural significance but also support wildlife populations. Many of these “cultural parks” maintain open landscapes to recreate land use patterns that existed at the times of the historical events. These open landscapes are primarily managed grasslands which could be maintained to benefit grassland birds. In 2005, the NPS initiated a project exploring the potential of “cultural parks” to support significant breeding grassland bird communities. This project involved parks within three NPS Inventory and Monitoring Program (I&M) networks, Mid-Atlantic, National Capital, and Eastern Rivers and Mountains. Five parks were selected for the initial focus of this study, all of which maintain open landscapes for interpretation of historic events. Most parks were selected because they represent the most extensive grassland habitats within their networks, with the rationale that if these parks cannot support significant breeding grassland bird communities, then parks with smaller acreages cannot support these communities either. The five parks included in this study are: Antietam National Battlefield, Fort Necessity National Battlefield, Gettysburg National Battlefield, Manassas National Battlefield, and Monocacy National Battlefield. This conceptual ecological model is one product of this project. The information presented below allows NPS Network Coordinators to understand the factors to consider when making decisions concerning grassland management within their networks. This model provides park Resource Managers with information on grassland ecology in the Mid-Atlantic Region, the ecological requirements of grassland birds likely to occur in their parks, and management issues that influence whether significant breeding populations can be expected to occupy grasslands created and maintained in the parks. The Resource Managers can then make informed decisions concerning their ability to create and maintain grassland habitats. The emphasis of this conceptual model is restricted to management of breeding grassland birds. Additional species may occur in this region during migration and winter, while habitat requirements of all grassland birds during nonbreeding seasons will differ from those described for the breeding season.

Natural Resource Report↗
USGS2022

Minimizing extinction risk in the face of uncertainty: Developing conservation strategies for 2 rapidly declining forest bird species on Kaua‘i Island

Many species around the world are declining precipitously as a result of multiple threats and changing climate. Managers tasked with protecting species often face difficult decisions in regard to identifying which threats should be addressed, given limited resources and uncertainty in the success of any identified management action. On Kaua‘i Island, Hawai‘i, USA, forest bird species have experienced accelerated declines over the last 20 years, and 2 species, the ‘akikiki ( Oreomystis bairdi ) and ‘akeke‘e ( Loxops caeruleirostris ), are now at the brink of extinction. Both species face multiple threats, and managers face difficult decisions on whether to mitigate threats in the wild, establish a captive population as insurance against extinction, translocate birds to novel locations, or some combination of these actions. Each set of actions (alternatives) would require substantial resources with considerable uncertainty in success. In 2014, we brought together 14 experts representing biologists and managers familiar with the species and island to develop a conservation strategy under a structured decision making (SDM) framework, an approach for making complex decisions under uncertainty. The group's challenge was to identify a set of alternatives that reduces the risk of extinction, set the foundation for one or more genetically viable, reproducing, stable to increasing populations in 10 years, and promote conditions for long-term persistence in the wild. Multiple alternatives were evaluated, via expert judgement, in terms of the probability they would achieve the objectives concerning immediate extinction risk, near-term viability, and adequacy of habitat. Factors that might impede the success of each action were also evaluated. The process identified the establishment of a captive population and efforts to stabilize the existing wild population as the approach most likely to meet the objectives of preventing imminent extinction and ensuring long-term viability.

Hawaii↗
USGS2024

Habitat amount and edge effects, not perch proximity, nest exposure, or vegetation diversity affect cowbird parasitism in agricultural landscapes

Context Prior research documented relationships between brown-headed cowbird ( Molothrus ater ) brood parasitism and edge effects, proximity of perches, and nest exposure. Those relationships have not been evaluated in agroecosystems containing extremes of fragmentation and vegetation diversity. Objectives We compared three existing hypotheses on how cowbirds locate host nests with two new hypotheses regarding habitat amount and vegetation diversity to determine how the configuration and location of agricultural conservation practices affect grassland bird nest parasitism rates and predicted rates for eight common conservation practices. Methods We assessed cowbird parasitism of grassland bird nests on corn and soybean farms in Iowa, USA, and measured perch proximity, nest exposure, edge effects, habitat amount, and vegetation diversity for each nest. We fit a global generalized linear mixed-effects model and compared importance of model parameters using odds ratios. We predicted parasitism likelihood for every subset model and averaged predictions to explore individual effects. Results The variables that most influenced parasitism rates included main effects for nest initiation day-of-season (OR = 0.71, CI 95 = 0.60–0.84) and the landscape variables of distance to nearest crop edge (0.63, 0.51–0.76) and proportion of grass land cover within 660 m (0.75, 0.57–1.00). We found little support that perch proximity, nest exposure, or native vegetation diversity affected parasitism. We also assessed parasitism likelihood by conservation practice and found no significant differences. Conclusions Our results provide evidence to support the edge effect and habitat amount hypotheses, but not the nest exposure, vegetation diversity, or perch proximity hypotheses.

Iowa↗
USGS2012

A risk-based approach to evaluating wildlife demographics for management in a changing climate: A case study of the Lewis's Woodpecker

Given the projected threat that climate change poses to biodiversity, the need for proactive response efforts is clear. However, integrating uncertain climate change information into conservation planning is challenging, and more explicit guidance is needed. To this end, this article provides a specific example of how a risk-based approach can be used to incorporate a species' response to climate into conservation decisions. This is shown by taking advantage of species' response (i.e., impact) models that have been developed for a well-studied bird species of conservation concern. Specifically, we examine the current and potential impact of climate on nest survival of the Lewis's Woodpecker ( Melanerpes lewis ) in two different habitats. To address climate uncertainty, climate scenarios are developed by manipulating historical weather observations to create ensembles (i.e., multiple sequences of daily weather) that reflect historical variability and potential climate change. These ensembles allow for a probabilistic evaluation of the risk posed to Lewis's Woodpecker nest survival and are used in two demographic analyses. First, the relative value of each habitat is compared in terms of nest survival, and second, the likelihood of exceeding a critical population threshold is examined. By embedding the analyses in a risk framework, we show how management choices can be made to be commensurate with a defined level of acceptable risk. The results can be used to inform habitat prioritization and are discussed in the context of an economic framework for evaluating trade-offs between management alternatives.

Idaho↗