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At least 91 records · Page 5Linked to original sources
USGS2001

Nest survival of forest birds in the Mississippi Alluvial Valley

In the Mississippi Alluvial Valley, flood control has led to a drastic reduction in the area of forest habitat and altered the patchwork of forest cover types. Silvicultural management of the remaining fragmented forests has changed to reflect the altered hydrology of the forests, current economic conditions of the area, and demand for forest products. Because forest type and silvicultural management impact forest birds, differences in avian productivity within these forests directly impact bird conservation. To assist in conservation planning, we evaluated daily nest survival, nest predation rates, and brood parasitism rates of forest birds in relation to different forest cover types and silvicultural management strategies within this floodplain. Within bottomland hardwood forests, nest success of blue-gray gnatcatcher ( Polioptila caerulea , 13%), eastern towhee ( Pipilo erythrophthalmus , 28%), indigo bunting ( Passerina cyanea , 18%), northern cardinal ( Cardinalis cardinalis , 22%), and yellow-billed cuckoo ( Coccyzus americanus , 18%) did not differ from that within intensively managed cottonwood plantations. However, average daily survival of 542 open-cup nests of 19 bird species in bottomland hardwoods (0.9516 ± 0.0028, ∼27% nest success) was greater than that of 543 nests of 18 species in cottonwood plantations (0.9298 ± 0.0035, ∼15% nest success). Differences in daily nest survival rates likely resulted from a combination of differences in the predator community -- particularly fire ants ( Solenopsis invicta ) -- and a marked difference in species composition of birds breeding within these 2 forest types. At least 39% of nests in bottomland hardwood forests and 65% of nests in cottonwood plantations were depredated. Rates of parasitism by brown-headed cowbirds ( Molothrus ater ) were greater in managed cottonwoods (24%) than in bottomland hardwoods (9%). Nest success in planted cottonwood plantations for 18 species combined (∼14%), and for yellow-breasted chat ( Icteria virens , 7%), eastern towhee (14%), indigo bunting (14%), and northern cardinal (17%) did not differ from nest success in cottonwood plantations that were coppiced from root sprouts following pulpwood harvest. Within bottomland hardwood forests, uneven-aged group-selection timber harvest reduced the combined daily nest survival of all species from 0.958 to 0.938, which reduced nest success by about 14%. Specifically, timber harvest reduced nest success of species that nest in the forest midstory and canopy, such as Acadian flycatcher ( Empidonax virescens ), from 32% before harvest to 14% after harvest. Conversely, those species that nest primarily in the shrubby understory-such as northern cardinal-were not affected by timber harvest and maintained an overall nest success of about 33%. Thus, birds nesting in the understory of bottomland hardwood forests are not adversely impacted by selective timber harvest, but there is a short-term reduction in nest success for birds that nest in the canopy and midstory.

Louisiana, Mississippi↗
USGS2011

Monitoring habitat restoration projects: U.S. Fish and Wildlife Service Pacific Region Partners for Fish and Wildlife Program and Coastal Program Protocol

The U.S. Fish and Wildlife Service's (FWS) Pacific Region (Region 1) includes more than 158 million acres (almost 247,000 square miles) of land base in Idaho, Oregon, Washington, Hawai`i, the Commonwealth of the Northern Mariana Islands, American Samoa, Guam, the Republic of Palau, the Federated States of Micronesia, and the Republic of the Marshall Islands. Region 1 is ecologically diverse with landscapes that range from coral reefs, broadleaf tropical forests, and tropical savannahs in the Pacific Islands, to glacial streams and lakes, lush old-growth rainforests, inland fjords, and coastal shoreline in the Pacific Northwest, to the forested mountains, shrub-steppe desert, and native grasslands in the Inland Northwest. Similarly, the people of the different landscapes perceive, value, and manage their natural resources in ways unique to their respective regions and cultures. The Partners for Fish and Wildlife Program (Partners Program) and Coastal Program work with a variety of partners in Region 1 including individual landowners, watershed councils, land trusts, Soil and Water Conservation Districts, non-governmental organizations, Tribal governments, Native Hawaiian organizations, and local, State, and Federal agencies. The Partners Program is the FWS's vanguard for working with private landowners to voluntarily restore and conserve fish and wildlife habitat. Using non-regulatory incentives, the Partners Program engages willing partners to conserve and protect valuable fish and wildlife habitat on their property and in their communities. This is accomplished by providing the funding support and technical and planning tools needed to make on-the-ground conservation affordable, feasible, and effective. The primary goals of the Pacific Region Partners Program are to: Promote citizen and community-based stewardship efforts for fish and wildlife conservation Contribute to the recovery of at-risk species, Protect the environmental integrity of the National Wildlife Refuges, Contribute to the implementation of the State Comprehensive Wildlife Conservation Strategies, and Help achieve the objectives of the National Fish Habitat Partnerships and regionally based bird conservation plans (for example, North American Waterfowl Management Plan, U.S. Pacific Island Shorebird Conservation Plans, Intermountain West Regional Shorebird Plan, etc.). The Partners Program accomplishes these priorities by: Developing and maintaining strong partnerships, and delivering on-the-ground habitat restoration projects designed to reestablish habitat function and restore natural processes; Addressing key habitat limiting factors for declining species; Providing corridors for wildlife and decrease impediments to native fish and wildlife migration; and Enhancing native plant communities by reducing invasive species and improving native species composition. The Coastal Program is a voluntary fish and wildlife conservation program that focuses on watershed-scale, long-term collaborative resource planning and on-the-ground restoration projects in high-priority coastal areas. The Coastal Program conducts planning and restoration work on private, State, and Federal lands, and partnerships with other agencies-Native American Tribes, citizens, and organizations are emphasized. Coastal Program goals include restoring and protecting coastal habitat, providing technical and cost-sharing assistance where appropriate, supporting community-based restoration, collecting and developing information on the status of and threats to fish and wildlife, and using outreach to promote stewardship of coastal resources. The diversity of habitats and partners in Region 1 present many opportunities for conducting restoration projects. Faced with this abundance of opportunity, the Partners Program and Coastal Program must ensure that limited staffing and project dollars are allocated to benefit the highest priority resources and achieve the highest quality results for Federal trust species. In 2007, the Partners Program and Coastal Program developed a Strategic Plan to guide program operations and more efficiently conserve habitat by focusing partnership building and habitat improvement actions within 35 Partners Program Focus Areas and 9 Coastal Program Focus Areas (U.S. Fish and Wildlife Service, 2010). The Strategic Plan also contains four other goals: broaden and strengthen partnerships; improve information sharing and communications; enhance workforce; and increase accountability to ensure that program resources are used efficiently and effectively. This protocol will help achieve all goals of the Strategic Plan.

Techniques and Methods↗
USGS2003

Developing a general conceptual framework for avian conservation science

Avian conservation science in North America has produced a variety of monitoring programs designed to provide information on population status of birds. Waterfowl surveys provide population estimates for breeding ducks over most of the continent, the North American Breeding Bird Survey (BBS) provides indexes to population change for >400 breeding bird species, and many other surveys exist that index bird populations at a variety of scales and seasons. However, many fundamental questions about bird population change remain unanswered. I suggest that analyses of monitoring data provide limited understanding of causes of population change, and that the declining species paradigm (Caughley 1994) is sometimes an inefficient approach to increasing our understanding of causes of population change. In North America, the North American Bird Conservation Initiative (NABCI) provides an opportunity to implement alternative approaches that use management, modeling of population responses to management, and monitoring in combination to increase our understanding of bird populations. In adaptive resources management, modeling provides predictions about consequences of management, and monitoring data allow us to assess the population consequences of management. In this framework, alternative hypotheses about response of populations to management can be evaluated by formulating a series of models with differing structure, and management and monitoring provide information about which model best predicts population response.

Ornis Hungarica↗
USGS2025

Effects of northern bobwhite habitat management on avian species of conservation concern

The umbrella species concept is often used as a tool to guide management decisions and focus efforts towards one focal species whose habitat needs overlap that of other species. We assessed this concept in the context of an agriculturally dominant landscape using one of the most well-studied avian species in North America as a target for conservation efforts: Northern Bobwhite ( Colinus virginianus ). This species is often viewed as an umbrella species for grassland and shrubland bird conservation throughout its native range due to its complex, year-round habitat requirements. We assessed the influence of Northern Bobwhite habitat management on six songbird species of conservation concern in Iowa by evaluating similarities and differences in habitat associations between each species. Our objectives were to (1) assess which vegetation characteristics were most strongly associated with Northern Bobwhite occupancy and (2) evaluate whether those characteristics were also associated with abundance of the focal songbird species. We used occupancy and N-mixture models to assess relationships between vegetation characteristics and Northern Bobwhite occupancy and songbird abundance, respectively. We found that the vegetation characteristics most strongly associated with Northern Bobwhite occupancy probability were the amounts of closed canopy forest, early successional woody vegetation, non-vegetated areas, and percent cover of bare ground. We found that for some of these covariates, including the amounts of forest and non-vegetated area, the effect on focal songbird species abundance aligned with Northern Bobwhite occupancy. For others, including the amount of early successional woody vegetation, the effects differed. This assessment of overlap and variability in habitat associations suggests that Northern Bobwhite-targeted management can provide benefits to other grassland and shrubland birds, but may also come with some trade-offs. This work adds to existing literature, further highlighting the nuances of the umbrella species concept in that land management benefits from the assessment of trade-offs and inclusion of local community dynamics.

Iowa↗
USGS2015

An empirical evaluation of landscape energetic models: Mallard and American black duck space use during the non-breeding period

Bird conservation Joint Ventures are collaborative partnerships between public agencies and private organizations that facilitate habitat management to support waterfowl and other bird populations. A subset of Joint Ventures has developed energetic carrying capacity models (ECCs) to translate regional waterfowl population goals into habitat objectives during the non-breeding period. Energetic carrying capacity models consider food biomass, metabolism, and available habitat to estimate waterfowl carrying capacity within an area. To evaluate Joint Venture ECCs in the context of waterfowl space use, we monitored 33 female mallards ( Anas platyrhynchos ) and 55 female American black ducks ( A. rubripes ) using global positioning system satellite telemetry in the central and eastern United States. To quantify space use, we measured first-passage time (FPT: time required for an individual to transit across a circle of a given radius) at biologically relevant spatial scales for mallards (3.46 km) and American black ducks (2.30 km) during the non-breeding period, which included autumn migration, winter, and spring migration. We developed a series of models to predict FPT using Joint Venture ECCs and compared them to a biological null model that quantified habitat composition and a statistical null model, which included intercept and random terms. Energetic carrying capacity models predicted mallard space use more efficiently during autumn and spring migrations, but the statistical null was the top model for winter. For American black ducks, ECCs did not improve predictions of space use; the biological null was top ranked for winter and the statistical null was top ranked for spring migration. Thus, ECCs provided limited insight into predicting waterfowl space use during the non-breeding season. Refined estimates of spatial and temporal variation in food abundance, habitat conditions, and anthropogenic disturbance will likely improve ECCs and benefit conservation planners in linking non-breeding waterfowl habitat objectives with distribution and population parameters. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Arkansas, Delaware, Louisiana, Michigan, New Jerse↗
USGS2005

High priority needs for range-wide monitoring of North American landbirds

This document is an extension of work done for the Partners in Flight North American Landbird Conservation Plan (Rich et al. 2004). The Continental Plan reviewed conservation status of the 448 native landbird species that regularly breed in the United States and Canada. Two groups of species were identified as having high conservation importance: the PIF Watch List, made up of species for which there is conservation concern, and Stewardship Spices that are particularly characteristic of regional avifaunas. In addition, continental scale monitoring needs were identified for all species. Here we extend the monitoring needs aspect of the Plan, providing additional detail and suggesting the best means of filling the gaps in broad-scale, long-term trend monitoring. This analysis and report was compiled by the Partners in Flight (PIF) Science Committee as a contribution to current work by the North American Bird Conservation Initiative to assess the status of bird population monitoring in North America and to make recommendations for improvements.

Partners in Flight Technical Series↗
USGS2006

Patch size and landscape effects on density and nesting success of grassland birds

Current management recommendations for grassland birds in North America emphasize providing large patches of grassland habitat within landscapes that have few forest or shrubland areas. These Bird Conservation Areas are being proposed under the assumption that large patches of habitat in treeless landscapes will maintain viable populations of grassland birds. This assumption requires that patch size and landscape features affect density and nesting success of grassland birds, and that these effects are consistent among years and regions and across focal species. However, these assumptions have not yet been validated for grassland birds, and the relative importance of local vegetation structure, patch size, and landscape composition on grassland bird populations is not well known. In addition, factors influencing grassland bird nesting success have been investigated mostly in small-scale and short-duration studies. To develop management guidelines for grassland birds, we tested the spatial and temporal repeatability of the influence of patch size and landscape composition on density and nesting success of 3 grassland passerines, after controlling for local-scale vegetation structure, climate, and—when analyzing nest success—bird density. We conducted our study during 4 years (1998–2001) in 44 study plots that were set up in 3 regions of the northern tallgrass prairie in Minnesota and North Dakota, USA. In these study plots we measured density and nesting success of clay-colored sparrows ( Spizella pallida ), Savannah sparrows ( Passerculus sandwichensis ), and bobolinks ( Dolichonyx oryzivorus ). Statistical models indicated that density was influenced by patch size, landscape, region, and local vegetation structure more so than by local vegetation structure alone. Both magnitude and direction of the response of density to patch size varied among regions, years, and species. In contrast, the direction of landscape effects was consistent among regions, years, and between Savannah sparrows and bobolinks. In each species, this landscape effect was independent of patch size. Nesting success was not clearly influenced by patch size or landscape composition, and none of the factors that influenced avian density also influenced nesting success in any of the 3 species. General statements on “optimal habitat” for grassland birds should therefore be viewed cautiously. Instead, long-term studies in different regions as well as a deeper understanding of the local system are needed to determine which factors are most important for grassland birds in a particular area.

Journal of Wildlife Management↗
USGS2013

The U.S. Geological Survey Bird Banding Laboratory: an integrated scientific program supporting research and conservation of North American birds

The U.S. Geological Survey (USGS) Bird Banding Laboratory (BBL) was established in 1920 after ratification of the Migratory Bird Treaty Act with the United Kingdom in 1918. During World War II, the BBL was moved from Washington, D.C., to what is now the USGS Patuxent Wildlife Research Center (PWRC). The BBL issues permits and bands to permittees to band birds, records bird band recoveries or encounters primarily through telephone and Internet reporting, and manages more than 72 million banding records and more than 4.5 million records of encounters using state-of-the-art technologies. Moreover, the BBL also issues bands and manages banding and encounter data for the Canadian Bird Banding Office (BBO). Each year approximately 1 million bands are shipped from the BBL to banders in the United States and Canada, and nearly 100,000 encounter reports are entered into the BBL systems. Banding data are essential for regulatory programs, especially migratory waterfowl harvest regulations. The USGS BBL works closely with the U.S. Fish and Wildlife Service (USFWS) to develop regulations for the capture, handling, banding, and marking of birds. These regulations are published in the Code of Federal Regulations (CFR). In 2006, the BBL and the USFWS Division of Migratory Bird Management (DMBM) began a comprehensive revision of the banding regulations. The bird banding community has three major constituencies: Federal and State agency personnel involved in the management and conservation of bird populations that include the Flyway Councils, ornithological research scientists, and avocational banders. With increased demand for banding activities and relatively constant funding, a Federal Advisory Committee (Committee) was chartered and reviewed the BBL program in 2005. The final report of the Committee included six major goals and 58 specific recommendations, 47 of which have been addressed by the BBL. Specifically, the Committee recommended the BBL continue to support science, conservation, and management of birds through the use of banding and banding data and that the BBL be managed by the USGS and located at the USGS Patuxent Wildlife Research Center (PWRC) in Laurel, Maryland. Recommendations that have not been implemented include those already addressed by other organizations, as well as lower priority, such as developing a BBL business plan. The comprehensive review and recommendations of the Committee, the response of the BBL to address the Committee’s recommendations, and other improvements to its operations have positioned the BBL to provide a high level of service to the banding community. As new technologies are developed and incorporated into BBL operations, further efficiencies are expected to enable the BBL to continue to meet emerging scientific needs.

Open-File Report↗
USGS2004

Grassland vegetation and bird communities in the southern Great Plains of North America

Structure and composition of vegetation and abundance of breeding birds in grasslands seeded to Old World bluestem (Bothriochloa ischmaeum) were compared to native mixed prairie in the southern Great Plains of North America. Abundance of birds was determined using fixed-radius point counts. Detrended correspondence analysis was used to compare plant community composition and canonical correspondence analysis was used to examine the relationships between plant species composition and vegetation structure with the bird community. Plant species composition differed distinctly between seeded grassland and native mixed prairie, but the differences were not reflected in habitat structure, bird community composition, or abundance of bird species. Seeded grassland was inferior to native mixed prairie in terms of diversity of plant species, but that difference did not translate into meaningful differences in structure that drove habitat selection by breeding birds. Conservation programs that promote establishment of seeded grassland and do not allow for suitable disturbance regimes will selectively benefit a narrow suite of birds regardless of plant species composition. ?? 2004 Elsevier B.V. All rights reserved.

Agriculture, Ecosystems and Environment↗
USGS2019

Influence of forest harvest severity and time since perturbation on conservation of North American birds

I calculated avian conservation scores, based on published quantitative assessment of bird presence (typically relative abundance) and regional Partners in Flight conservation concern score of each species. I related these avian conservation scores to severity of forest perturbation (i.e., % retention) and number of years since perturbation for forest stands within North America. I characterized avian response to perturbation by comparing avian conservation score on perturbed stands with that of paired unperturbed reference stands. Positive avian response to perturbation, representative of improved avian conservation status, was found when forest retention was >20% of coniferous forests or 25%–75% of hardwood forests. Positive avian response was greatest ~10 years after perturbation that retained 58% of conifer forests or 49% of hardwood forests. Increased avian conservation scores following perturbation may last for up to 23 years after perturbation but occur and diminish sooner with greater forest retention. Average annual avian response, over 23 years post-perturbation, was greatest when 30%–50% of hardwood stands were retained and when 50%–70% of conifer stands were retained.

Forest Ecology and Management↗
USGS2013

Golden eagle population trends in the western United States: 1968-2010

In 2009, the United States Fish and Wildlife Service promulgated permit regulations for the unintentional lethal take (anthropogenic mortality) and disturbance of golden eagles (Aquila chrysaetos). Accurate population trend and size information for golden eagles are needed so agency biologists can make informed decisions when eagle take permits are requested. To address this need with available data, we used a log-linear hierarchical model to average data from a late-summer aerial-line-transect distance-sampling survey (WGES) of golden eagles in the United States portions of Bird Conservation Region (BCR) 9 (Great Basin), BCR 10 (Northern Rockies), BCR 16 (Southern Rockies/Colorado Plateau), and BCR 17 (Badlands and Prairies) from 2006 to 2010 with late-spring, early summer Breeding Bird Survey (BBS) data for the same BCRs and years to estimate summer golden eagle population size and trends in these BCRs. We used the ratio of the density estimates from the WGES to the BBS index to calculate a BCR-specific adjustment factor that scaled the BBS index (i.e., birds per route) to a density estimate. Our results indicated golden eagle populations were generally stable from 2006 to 2010 in the 4 BCRs, with an estimated average rate of population change of −0.41% (95% credible interval [CI]: −4.17% to 3.40%) per year. For the 4 BCRs and years, we estimated annual golden eagle population size to range from 28,220 (95% CI: 23,250–35,110) in 2007 to 26,490 (95% CI: 21,760–32,680) in 2008. We found a general correspondence in trends between WGES and BBS data for these 4 BCRs, which suggested BBS data were providing useful trend information. We used the overall adjustment factor calculated from the 4 BCRs and years to scale BBS golden eagle counts from 1968 to 2005 for the 4 BCRs and for 1968 to 2010 for the 8 other BCRs (without WGES data) to estimate golden eagle population size and trends across the western United States for the period 1968 to 2010. In general, we noted slightly declining trends in southern BCRs and slightly increasing trends in northern BCRs. However, we estimated the average rate of golden eagle population change across all 12 BCRs for the period 1968–2010 as +0.40% per year (95% CI = −0.27% to 1.00%), suggesting a stable population. We also estimated the average rate of population change for the period 1990–2010 was +0.5% per year (95% CI = −0.33% to 1.3%). Our annual estimates of population size for the most recent decade range from 31,370 (95% CI: 25,450–39,310) in 2004 to 33,460 (95% CI: 27,380–41,710) in 2007. Our results clarify that golden eagles are not declining widely in the western United States. © 2013 The Wildlife Society.

Arizona;California;Colorado;Idaho;Iowa;Kansas;Minn↗
USGS2014

Identifying marine Important Bird Areas using at-sea survey data

Effective marine bird conservation requires identification of at-sea locations used by populations for foraging, staging, and migration. Using an extensive database of at-sea survey data spanning over 30 years, we developed a standardized and data-driven spatial method for identifying globally significant marine Important Bird Areas in Alaska. To delineate these areas we developed a six-step process: binning data and accounting for unequal survey effort, filtering input data for persistence of species use, using a moving window analysis to produce maps representing a gradient from low to high abundance, drawing core area boundaries around major concentrations based on abundance thresholds, validating the results, and combining overlapping boundaries into important areas for multiple species. We identified 126 bird core areas which were merged into 59 pelagic sites important to 45 out of 57 species assessed. The final areas included approximately 34–38% of all marine birds in Alaska waters, within just 6% of the total area. We identified globally significant Important Bird Areas spanning 20 degrees of latitude and 56 degrees of longitude, in two different oceans, with climates ranging from temperate to polar. Although our maps did suffer from some data gaps, these gaps did not preclude us from identifying sites that incorporated 13% of the assessed continental waterbird population and 9% of the assessed global seabird population. The application of this technique over a large and productive region worked well for a wide range of birds, exhibiting a variety of foraging strategies and occupying a variety of ecosystem types.

Alaska↗
USGS2010

Change in avian abundance predicted from regional forest inventory data

An inability to predict population response to future habitat projections is a shortcoming in bird conservation planning. We sought to predict avian response to projections of future forest conditions that were developed from nationwide forest surveys within the Forest Inventory and Analysis (FIA) program. To accomplish this, we evaluated the historical relationship between silvicolous bird populations and FIA-derived forest conditions within 25 ecoregions that comprise the southeastern United States. We aggregated forest area by forest ownership, forest type, and tree size-class categories in county-based ecoregions for 5 time periods spanning 1963-2008. We assessed the relationship of forest data with contemporaneous indices of abundance for 24 silvicolous bird species that were obtained from Breeding Bird Surveys. Relationships between bird abundance and forest inventory data for 18 species were deemed sufficient as predictive models. We used these empirically derived relationships between regional forest conditions and bird populations to predict relative changes in abundance of these species within ecoregions that are anticipated to coincide with projected changes in forest variables through 2040. Predicted abundances of these 18 species are expected to remain relatively stable in over a quarter (27%) of the ecoregions. However, change in forest area and redistribution of forest types will likely result in changed abundance of some species within many ecosystems. For example, abundances of 11 species, including pine warbler (Dendroica pinus), brown-headed nuthatch (Sitta pusilla), and chuckwills- widow (Caprimulgus carolinensis), are projected to increase within more ecoregions than ecoregions where they will decrease. For 6 other species, such as blue-winged warbler (Vermivora pinus), Carolina wren (Thryothorus ludovicianus), and indigo bunting (Passerina cyanea), we projected abundances will decrease within more ecoregions than ecoregions where they will increase.

Forest Ecology and Management↗
USGS2011

Analysis of the North American Breeding Bird Survey using hierarchical models

We analyzed population change for 420 bird species from the North American Breeding Bird Survey (BBS) using a hierarchical log-linear model and compared the results with those obtained through route-regression analysis. Survey-wide trend estimates based on the hierarchical model were generally more precise than estimates from the earlier analysis. No consistent pattern of differences existed in the magnitude of trends between the analysis methods. Survey-wide trend estimates changed substantially for 15 species between route-regression and hierarchical-model analyses. We compared regional estimates for states, provinces, and Bird Conservation Regions; differences observed in these regional analyses are likely a consequence of the route-regression procedure's inadequate accommodation of temporal differences in survey effort. We used species-specific hierarchical-model results to estimate composite change for groups of birds associated with major habitats and migration types. Grassland, aridland, and eastern-forest-obligate bird species declined, whereas urban—suburban species increased over the interval 1968–2008. No migration status group experienced significant changes, although Nearctic—Neotropical migrant species showed intervals of decline and permanent resident species increased almost 20% during the interval. Hierarchical-model results better portrayed patterns of population change over time than route-regression results. We recommend use of hierarchical models for BBS analyses.

North America↗
USGS2011

Comparison of statistical and theoretical habitat models for conservation planning: The benefit of ensemble prediction

Selection of a modeling approach is an important step in the conservation planning process, but little guidance is available. We compared two statistical and three theoretical habitat modeling approaches representing those currently being used for avian conservation planning at landscape and regional scales: hierarchical spatial count (HSC), classification and regression tree (CRT), habitat suitability index (HSI), forest structure database (FS), and habitat association database (HA). We focused our comparison on models for five priority forest-breeding species in the Central Hardwoods Bird Conservation Region: Acadian Flycatcher, Cerulean Warbler, Prairie Warbler, Red-headed Woodpecker, and Worm-eating Warbler. Lacking complete knowledge on the distribution and abundance of each species with which we could illuminate differences between approaches and provide strong grounds for recommending one approach over another, we used two approaches to compare models: rank correlations among model outputs and comparison of spatial correspondence. In general, rank correlations were significantly positive among models for each species, indicating general agreement among the models. Worm-eating Warblers had the highest pairwise correlations, all of which were significant ( P , 0.05). Red-headed Woodpeckers had the lowest agreement among models, suggesting greater uncertainty in the relative conservation value of areas within the region. We assessed model uncertainty by mapping the spatial congruence in priorities (i.e., top ranks) resulting from each model for each species and calculating the coefficient of variation across model ranks for each location. This allowed identification of areas more likely to be good targets of conservation effort for a species, those areas that were least likely, and those in between where uncertainty is higher and thus conservation action incorporates more risk. Based on our results, models developed independently for the same purpose (conservation planning for a particular species in a particular geography) yield different answers and thus different conservation strategies. We assert that using only one habitat model (even if validated) as the foundation of a conservation plan is risky. Using multiple models (i.e., ensemble prediction) can reduce uncertainty and increase efficacy of conservation action when models corroborate one another and increase understanding of the system when they do not.

Ecological Applications↗
USGS2021

Alaska landbird montoring survey: Alaska regional protocol framework for monitoring landbirds using point counts

Alaska provides habitat for 143 species of landbirds that occur regularly in the state, about half of which breed predominantly north of the border between the contiguous United States and Canada. The road-based North American Breeding Bird Survey (BBS) provides some data on population trends in Alaska, but most northern populations are inadequately monitored by this program because of a paucity of roads. To remedy this deficiency, Boreal Partners in Flight developed the Alaska Landbird Monitoring Survey (ALMS) to monitor breeding populations of landbirds in off-road areas of Alaska in tandem with data collected from the roadside BBS. The primary objective of ALMS is to monitor long-term population trends of landbirds and other species that can be monitored by diurnal point counts during the breeding season, including many shorebirds and aquatic birds. A secondary objective is to estimate landbird densities by habitat, which can be used to model avian distribution and abundance across Alaska. ALMS is a collaborative program whereby agencies and other entities conduct standardized surveys of breeding birds and their habitats on the lands they manage and then contribute the data to the U.S. Geological Survey Alaska Science Center for storage and analysis. The short-term implementation goal of ALMS is to monitor birds systematically within each of 100 randomly selected survey blocks, thereby matching the number of BBS surveys conducted in each of Alaska's five Bird Conservation Regions (BCRs). Each block has a mini-grid of 15−25 points that are surveyed biennially, with half of the blocks surveyed in alternating years. Survey blocks are stratified by accessibility and cost-effectiveness. Refuges may opt to limit sites to those accessible by foot, vehicle, boat, or fixed-wing aircraft, as these can be surveyed more inexpensively and reliably over time. Observers survey each point within a survey block for birds using a 10-min point count once per summer on a biennial basis. They collect corresponding habitat data during the first visit and at subsequent 10-year intervals or whenever a disturbance (e.g., fire, wind) has caused a significant change. USGS analyzes ALMS data jointly with BBS data to test for differences between off-road and roadside areas and to increase power to detect statewide trends. Additional blocks can be surveyed in areas that are more difficult and expensive to access as resources become available in the future. Long-term monitoring enables detection of change in bird populations in relation to fire, disease and insect damage, resource development, climate-related change, and other landscape-level disturbances across Alaska. Results from ALMS can also help prioritize conservation and research towards species before they become endangered and require expensive recovery programs.

Alaska↗
USGS2001

Book review: Birds of Delaware

Located along Delaware Bay and the Atlantic coast, the state of Delaware’s significance for bird conservation has been well established for decades. The extensive tidal habitats and marshes bordering Delaware Bay host shorebird and waterbird populations of hemispheric importance, and protecting these populations has become an urgent conservation priority in recent years. Other habitats found in the state vary from barrier beaches to dry coniferous woods on the coastal plain and mesophytic communities along the Piedmont in the north, allowing a diverse avifauna to prosper within a small geographic area. Ornithologists and birders have actively studied birds within the state for more than a century, but surprisingly, no single reference has provided a complete summary of the status and distribution of the state’s birds until publication of the Birds of Delaware . Review info: Birds of Delaware. By Gene K. Hess, Richard L. West, Maurice V. Barnhill III, and Lorraine M. Fleming, 2000. ISBN: 0-8229-4069-8, 635 pp.

Condor↗
USGS2006

Comparative dynamics of avian communities across edges and interiors of North American ecoregions

Aim Based on a priori hypotheses, we developed predictions about how avian communities might differ at the edges vs. interiors of ecoregions. Specifically, we predicted lower species richness and greater local turnover and extinction probabilities for regional edges. We tested these predictions using North American Breeding Bird Survey (BBS) data across nine ecoregions over a 20-year time period. Location Data from 2238 BBS routes within nine ecoregions of the United States were used. Methods The estimation methods used accounted for species detection probabilities < 1. Parameter estimates for species richness, local turnover and extinction probabilities were obtained using the program COMDYN. We examined the difference in community-level parameters estimated from within exterior edges (the habitat interface between ecoregions), interior edges (the habitat interface between two bird conservation regions within the same ecoregion) and interior (habitat excluding interfaces). General linear models were constructed to examine sources of variation in community parameters for five ecoregions (containing all three habitat types) and all nine ecoregions (containing two habitat types). Results Analyses provided evidence that interior habitats and interior edges had on average higher bird species richness than exterior edges, providing some evidence of reduced species richness near habitat edges. Lower average extinction probabilities and turnover rates in interior habitats (five-region analysis) provided some support for our predictions about these quantities. However, analyses directed at all three response variables, i.e. species richness, local turnover, and local extinction probability, provided evidence of an interaction between habitat and region, indicating that the relationships did not hold in all regions. Main conclusions The overall predictions of lower species richness, higher local turnover and extinction probabilities in regional edge habitats, as opposed to interior habitats, were generally supported. However, these predicted tendencies did not hold in all regions.

Journal of Biogeography↗