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At least 163 records · Page 9Linked to original sources
USGS2008

Field Marks of a Celebration: Roger Tory Peterson's Centennial Birthday

A red letter day in my life was April 27, 1934, the day I first met Roger. A birding friend, Elisha Atkins, had invited Clinton Reynolds and me to dinner to meet a famous ornithologist. We would all be going on a field trip to Newburyport on the Massachusetts coast the next day. The dinner conversation revolved about a new field guide that Mr. Peterson had just completed and that would be available in a few days. I couldn?t wait to see it! I had been birding since 1930, keying out live birds with Chapman?s Handbook of Birds of Eastern North America (1912) and Hoffman?s Guide to the Birds of New England and Eastern New York (1904). Both books had extensive keys based on color, size, bill shape and season, and pictures of heads or feet of some species. Positive bird identification was a long and tedious process. The field trip the next day with Roger was memorable, not for finding any rare or unusual birds, but for learning how to identify birds to species at a single good glance. I recall asking Roger if he could find a ring-billed gull among a group of gulls resting on a roof beside the Merrimac River. He immediately said, ?No there aren?t any ring-bills there; they would be immediately apparent by their slimmer shape.? There was no need to check the foot color on each bird. While it is easy to say that Roger revolutionized field guides, I truly believe there are few people worldwide under the age of 90 who can really appreciate the difference between the old way of keying out birds and the instant recognition promoted by the Peterson system. Today we take for granted that amateurs can identify birds accurately. Monitoring bird populations by Breeding Bird Surveys, atlas studies, Breeding Bird Censuses, migration banding, and many other studies relies on it. None of these would be possible if we were still keying out live birds using books designed to identify dead birds in the hand.

Audubon Naturalist News↗
USGS2007

Rainforest birds: A land manager's guide to breeding bird habitat in young conifer forests in the Pacific Northwest

This document (hereafter Guide) has been prepared to assist land managers interested in conducting conservation and management activities to benefit breeding birds associated with young conifer forests in the Pacific Northwest. Audiences targeted for use of the Guide include land trusts, watershed councils, non-commercial private land owners, forest products companies, land-managing conservation organizations, government agencies, tribes, and First Nations. We hope the Guide will be a useful and valuable tool to support any of the variety of reasons to manage for bird habitat in young conifer forests (for example, regulatory, biodiversity, bird conservation, and forest certification standards). Information provided in the Guide is intended to support both the development of conservation or management plans and the implementation of on-the-ground management activities that have the potential to benefit breeding bird populations. The degree to which a land manager is willing or able to manage for bird habitat is a decision based on many factors which are beyond the scope of the Guide. We assume users of the Guide already have an interest in managing for bird habitat as one of several objectives that land managers must typically balance. However, it is not our purpose in the Guide to discuss integration of bird habitat management with other management objectives. Our objective is simply to provide those interested in bird conservation with information and recommendations on: the habitat conditions and features needed by breeding bird species, and how breeding bird species respond to particular management activities. Much of the information on breeding bird habitat is presented in tabular format in the appendices. Because the latitudinal and elevational coverage of the Guide is extensive, there can be considerable variation in the habitat types and conditions with which bird species are associated. Thus, it is important to recognize that the habitat relationships of a species may vary throughout the Pacific Northwest. Information presented in the appendices that categorizes bird-habitat relationships should not be regarded as absolute, but should be used as a tool to help prioritize conservation efforts toward species that have a significant degree of association with habitat parameters, such as forest type or successional stage. An underlying premise of the Guide is that forest management has a direct and significant influence on bird populations. Consequently, manipulation of forest conditions as part of forest management can be designed and implemented to achieve bird conservation objectives (Busing and Garman, 2002; Lehmkuhl and others, 2002). It is not our intent to describe all the potential forest management activities that could be conducted to achieve the desired habitat conditions for birds. Those need to be determined locally by assessing the most ecologically appropriate management at each site. However, to assist land managers, the Guide offers some basic forest management activities that are widely accepted for achieving habitat conditions and features which benefit breeding birds.

Scientific Investigations Report↗
USGS2017

How do en route events around the Gulf of Mexico influence landbird populations

Habitats around the Gulf of Mexico (GOM) provide critical resources for Nearctic–Neotropical migratory landbirds, the majority of which travel across or around the GOM every spring and fall as they migrate between temperate breeding grounds in North America and tropical wintering grounds in the Caribbean and Central and South America. At the same time, ecosystems in the GOM are changing rapidly, with unknown consequences for migratory landbird populations, many of which are experiencing population declines. In general, the extent to which events encountered en route limit migratory bird populations is not well understood. At the same time, information from weather surveillance radar, stable isotopes, tracking, eBird, and genetic datasets is increasingly available to address many of the unanswered questions about bird populations that migrate through stopover and airspace habitats in the GOM. We review the state of the science and identify key research needs to understand the impacts of en route events around the GOM region on populations of intercontinental landbird migrants that breed in North America, including: (1) distribution, timing, and habitat associations; (2) habitat characteristics and quality; (3) migratory connectivity; and (4) threats to and current conservation status of airspace and stopover habitats. Finally, we also call for the development of unified and comprehensive long-term monitoring guidelines and international partnerships to advance our understanding of the role of habitats around the GOM in supporting migratory landbird populations moving between temperate breeding grounds and wintering grounds in Mexico, Central and South America, and the Caribbean.

The Condor↗
USGS2025

Disease-driven collapse of the native Kauaʻi avifauna and the rise of introduced bird species

Hawaii hosts one of Earth’s most unique and threatened avifaunas. Upslope migration of mosquito-vectored avian malaria on Kauaʻi (maximum elevation 1,598 m) has likely caused its rapid loss of avifaunal diversity; only 8 of 13 historic forest bird species remain. We update the status and trends of Kauaʻi forest bird populations since the original (1981) surveys using the latest (2023) survey data and distance sampling. We fit detection functions to species-specific count data and stratified estimates across the Interior (since 1981) and Exterior (since 2000) survey areas, and between low (900–1,100 m), medium (1,100–1,300 m) and high (> 1,300 m) elevation bands (since 2000). Log-linear trends of ʻakekeʻe ( Loxops caeruleirostris ), ʻanianiau ( Magumma parva ), ʻiʻiwi ( Drepanis coccinea ), and Kauaʻi ʻamakihi ( Chlorodrepanis stejnegeri ) steeply declined across the timeseries, with extinction of ʻakekeʻe and ʻiʻiwi expected before 2050. Undetected in 2023, ʻakikiki ( Oreomystis bairdi ) were excluded from analysis. ʻApapane ( Himatione sanguinea ), Kauaʻi ʻelepaio ( Chasiempis sclateri ), Chinese hwamei ( Garrulax canorus ), and white-rumped shama ( Copsychus malabaricus ) were stable overall. Northern cardinal ( Cardinalis cardinalis ) steadily declined, whereas Japanese bush warbler ( Horornis diphone ) and warbling white-eye ( Zosterops japonicus ) exponentially increased. Taxonomic and functional diversity did not vary greatly across our timeseries, while the proportion of introduced species in the Exterior increased from 34 to 59%. However, introduced species do not replace the losses of ecological functions from native species, whose populations are likely declining from avian malaria. Future monitoring can be used to evaluate forest bird population responses to mosquito suppression using the Incompatible Insect Technique.

Hawaii↗
USGS2017

Low pathogenic avian influenza viruses in wild migratory waterfowl in a region of high poultry production, Delmarva, Maryland

Migratory waterfowl are natural reservoirs for low pathogenic avian influenza viruses (AIVs) and may contribute to the long-distance dispersal of these pathogens as well as spillover into domestic bird populations. Surveillance for AIVs is critical to assessing risks for potential spread of these viruses among wild and domestic bird populations. The Delmarva Peninsula on the east coast of the United States is both a key convergence point for migratory Atlantic waterfowl populations and a region with high poultry production (>4,700 poultry meat facilities). Sampling of key migratory waterfowl species occurred at 20 locations throughout the Delmarva Peninsula in fall and winter of 2013–14. Samples were collected from 400 hunter-harvested or live-caught birds via cloacal and oropharyngeal swabs. Fourteen of the 400 (3.5%) birds sampled tested positive for the AIV matrix gene using real-time reverse transcriptase PCR, all from five dabbling duck species. Further characterization of the 14 viral isolates identified two hemagglutinin (H3 and H4) and four neuraminidase (N2, N6, N8, and N9) subtypes, which were consistent with isolates reported in the Influenza Research Database for this region. Three of 14 isolates contained multiple HA or NA subtypes. This study adds to the limited baseline information available for AIVs in migratory waterfowl populations on the Delmarva Peninsula, particularly prior to the highly pathogenic AIV A(H5N8) and A(H5N2) introductions to the United States in late 2014.

Delaware, Maryland↗
USGS2010

Effects of wildlife forestry on abundance of breeding birds in bottomland hardwood forests of Louisiana

Effects of silvicultural activities on birds are of increasing interest because of documented national declines in breeding bird populations for some species and the potential that these declines are in part due to changes in forest habitat. Silviculturally induced disturbances have been advocated as a means to achieve suitable forest conditions for priority wildlife species in bottomland hardwood forests. We evaluated how silvicultural activities on conservation lands in bottomland hardwood forests of Louisiana, USA, influenced species-specific densities of breeding birds. Our data were from independent studies, which used standardized point-count surveys for breeding birds in 124 bottomland hardwood forest stands on 12 management areas. We used Program DISTANCE 5.0, Release 2.0 ( Thomas et al. 2006 ) to estimate density for 43 species with >50 detections. For 36 of those species we compared density estimates among harvest regimes (individual selection, group selection, extensive harvest, and no harvest). We observed 10 species with similar densities in those harvest regimes compared with densities in stands not harvested. However, we observed 10 species that were negatively impacted by harvest with greater densities in stands not harvested, 9 species with greater densities in individual selection stands, 4 species with greater densities in group selection stands, and 4 species with greater densities in stands receiving an extensive harvest (e.g., >40% canopy removal). Differences in intensity of harvest influenced densities of breeding birds. Moreover, community-wide avian conservation values of stands subjected to individual and group selection, and stands not harvested, were similar to each other and greater than that of stands subjected to extensive harvest that removed >40% canopy cover. These results have implications for managers estimating breeding bird populations, in addition to predicting changes in bird communities as a result of prescribed and future forest management practices.

Louisiana↗
USGS2018

Artificial light at night confounds broad-scale habitat use by migrating birds

With many of the world's migratory bird populations in alarming decline, broad-scale assessments of responses to migratory hazards may prove crucial to successful conservation efforts. Most birds migrate at night through increasingly light-polluted skies. Bright light sources can attract airborne migrants and lead to collisions with structures, but might also influence selection of migratory stopover habitat and thereby acquisition of food resources. We demonstrate, using multi-year weather radar measurements of nocturnal migrants across the northeastern U.S., that autumnal migrant stopover density increased at regional scales with proximity to the brightest areas, but decreased within a few kilometers of brightly-lit sources. This finding implies broad-scale attraction to artificial light while airborne, impeding selection for extensive forest habitat. Given that high-quality stopover habitat is critical to successful migration, and hindrances during migration can decrease fitness, artificial lights present a potentially heightened conservation concern for migratory bird populations.

Connecticut, Delaware, Maine, Maryland, Massachuse↗
USGS1991

On forming an Ornithological Council

It has begun to bother me that the ornithological societies seem to be playing an extremely minor role in anything to do with conserving, preserving, or salvaging the environment. We realize-or we tell each other that we do-that birds are an important part of the world's ecosystems, that they can often serve as indicator species of environmental problems, that what affects bird populations can and will eventually affect the human population. But as organizations, we lack a mechanism to tell anyone other than ourselves about our concerns or how the knowledge our study produces can be used to help efforts to protect either the birds themselves or the environment of which they and we are parts. We can, and some do, share our concerns and knowledge individually, but we have no effective way to say that 5,000 ornithologists think that "Plan A is a good idea" or "Plan B could lead to declines in bird populations" or even that "Plan C would have a very bad (or good) effect on the scientific study of birds that is needed to know whether Plans A and B are good." Our current mechanism for action is pretty much restricted to adopting resolutions saying, in effect, "We think you shouldn't have done that" or "We wish you would do something." Even the timing of this mechanism leaves much to be desired if we really intend to have any effect.

The Auk↗
USGS1996

Artificial wetlands to augment use by estuarine birds

The value of natural wetlands to bird populations is well-recognized, and declines in waterfowl numbers are often attributed to losses in wetland area. if the destruction of wetland reduces bird populations, then adding wetland habitats might improve the situation. This idea was tested in Tijuana Estuary in the late 1980s.

California↗
USGS2023

Converting CRP grasslands to cropland, grazing land, or hayland: Effects on breeding bird abundances in the northern Great Plains of the United States

Recent declines of grassland bird populations in North America are linked to habitat loss and fragmentation associated with agricultural practices. One tool used to conserve soil, water and wildlife habitat on agricultural fields is the U.S. Department of Agriculture’s Conservation Reserve Program (CRP), the largest agricultural conservation program in the United States. Managers and conservationists recognize CRP as an important component of conserving grassland birds in the central portion of the United States. However, recent widespread expiration of CRP contracts could negatively influence grassland bird populations. Few studies have evaluated how former CRP-enrolled fields may function as grassland bird habitat. In this paper, we analyzed data from a long-term (1990–2017) study aimed at comparing grassland bird abundance (24 species) between idled CRP grasslands and fields where the CRP contracts expired. Some of these fields where contracts expired were maintained as pasture or hayland, and others were converted back to cropland. Estimated abundances of most species were considerably higher in idled CRP than in fields with expired CRP contracts. Post-CRP land use also appeared to affect most bird abundances, with lower abundance in grazed grasslands and haylands relative to idled CRP, but higher abundance than cropland. The responses of obligate and facultative grassland specialists to post-CRP management varied among species, with some being negative and some being positive depending on post-CRP land use, which is unsurprising given the variable habitat requirements of grassland birds. Our results have implications for wildlife managers who must design conservation strategies around the land use decisions of private landowners. Our results support the idea of maintaining a mosaic of undisturbed CRP grasslands and post-CRP grasslands that are hayed or grazed, which should guarantee some undisturbed nesting cover in the landscape for some bird species and some disturbed grasslands that may have long-term benefits for other species.

Minnesota, Montana, North Dakota, South Dakota↗
USGS2025

Population trends of native and non-native forest birds on the island of Molokai, Hawaii

Hawaiʻi’s avifauna has undergone profound changes over the past 1,000 years, with many endemic bird species driven to extinction and non-native introductions reshaping forest ecosystems. On the island of Molokaʻi, habitat degradation and the introduction of mosquito-borne disease, mainly avian malaria ( Plasmodium relictum ), have caused extinctions and severe declines in native forest bird populations. To assess these changes, point-transect distance sampling surveys were initiated in 1979 and 1980 and repeated six times, most recently in 2021, covering a 3,527 ha area. This study analyzes species composition, population densities, abundances, and long-term trends for species with sufficient detections using log-linear regression. Since 1979–1980, a total of 17 non-native and 3 native species were detected across all six surveys. The non-native Warbling White-eye ( Zosterops japonicus ) had the highest density and abundance in every survey, while abundance of Red-billed Leiothrix ( Leiothrix lutea ) significantly trended upward. The Japanese Bush Warbler ( Horornis diphone ) irrupted in the survey area, increasing in abundance by more than 99% since 1979–1980. Among native species, ʻApapane ( Himatione sanguinea ) populations increased by 33%, while Hawaiʻi ʻAmakihi ( Chlorodrepanis virens ) declined by 78% from their peak in 1995. Federally threatened ʻIʻiwi ( Drepanis coccinea ), highly susceptible to avian malaria, have not been recorded on Molokaʻi since 2010, and the endemic Olomaʻo ( Myadestes lanaiensis ) has not been detected since 1980 and is possibly extinct. Our results underscore the ongoing conservation crisis for Molokaʻi’s forest birds and the continued vulnerability of native birds to disease and habitat loss.

Hawaii↗
USGS2024

Coastal breeding bird phenology on the dredged-material islands of the Baptiste Collette Bayou, US Army Corps of Engineers, New Orleans District, Louisiana

Coastal bird populations in North America have experienced significant population declines over the past four decades, and many species have become dependent upon human-made islands and other sediment-based habitats created through dredged material deposition. We monitored the breeding phenology of coastal bird populations utilizing dredged-material islands and open depositional areas in the Baptiste Collette Bayou in coastal Louisiana. Monitoring began in early May, prior to when most coastal species begin nesting, and continued through late August, when most breeding activity has ceased. Semimonthly surveys included area searches by foot and boat. Two deposition areas and one island supported large numbers of foraging, roosting, or breeding birds; surveys on these areas included using spotting scopes to identify species and count nests or young. Six islands and two open deposition areas were monitored. We also collected high-definition and lidar imagery using an uncrewed aerial system (UAS) in June, during peak nesting season. We recorded 77,474 cumulative detections of 68 species. Virtually all colonial nesting birds (terns and skimmers) nested on Gunn Island in 2021. We discuss these results in the context of dredged-material deposition by the US Army Corps of Engineers, New Orleans District, and offer recommendations for management of these areas.

Louisiana↗
USGS2002

Book review: Bird census techniques, Second edition

Conservation concerns, federal mandates to monitor birds, and citizen science programs have spawned a variety of surveys that collect information on bird populations. Unfortunately, all too frequently these surveys are poorly designed and use inappropriate counting methods. Some of the flawed approaches reflect a lack of understanding of statistical design; many ornithologists simply are not aware that many of our most entrenched counting methods (such as point counts) cannot appropriately be used in studies that compare densities of birds over space and time. It is likely that most of the readers of The Condor have participated in a bird population survey that has been criticized for poor sampling methods. For example, North American readers may be surprised to read in Bird Census Techniques that the North American Breeding Bird Survey 'is seriously flawed in its design,' and that 'Analysis of trends is impossible from points that are positioned along roads' (p. 109). Our conservation efforts are at risk if we do not acknowledge these concerns and improve our survey designs. Other surveys suffer from a lack of focus. In Bird Census Techniques, the authors emphasize that all surveys require clear statements of objectives and an understanding of appropriate survey designs to meet their objectives. Too often, we view survey design as the realm of ornithologists who know the life histories and logistical issues relevant to counting birds. This view reflects pure hubris: survey design is a collaboration between ornithologists, statisticians, and managers, in which goals based on management needs are met by applying statistical principles for design to the biological context of the species of interest. Poor survey design is often due to exclusion of some of these partners from survey development. Because ornithologists are too frequently unaware of these issues, books such as Bird Census Techniques take on added importance as manuals for educating ornithologists about the relevance of survey design and methods and the often subtle interdisciplinary nature of surveys. Review info: Bird Census Techniques, Second Edition. By Colin J. Bibby, Neil D. Burgess, David A. Hill, and Simon H. Mustoe. 2000. Academic Press, London, UK. xvii 1 302 pp. ISBN 0- 12-095831-7.

Condor↗
USGS1999

Trichomoniasis

Avian trichomoniasis is caused by a single celled protozoan, Trichomonas gallinae. Avirulent T. gallinae strains that do not cause disease and highly virulent strains are found in nature and circulate within bird populations. The factors that make a strain virulent are not known, but they are thought to be controlled genetically within the parasite. Similarly, the reasons why an avirulent or a virulent form of the parasite is found within a bird population at any period of time also remain unknown. Virulent strains of T. gallinae have caused major mortality events or epizootics in doves and pigeons in addition to less visible, chronic losses (Table 25.1). Infection typically involves the upper digestive tract of doves and pigeons but other species have also been infected (Fig. 25.1).

Information and Technology Report↗
USGS2021

Breeding at higher latitude is associated with higher photoperiodic threshold and delayed reproductive development in a songbird

Many seasonally breeding animals exhibit a threshold day length (critical photoperiod; CPP) for gonadal growth, and populations breeding at higher latitudes typically have a higher CPP. Much less is known about latitudinal variation in CPP in migratory population that winter away from their breeding range and must time their reproduction to match favorable conditions at their destination. To address the relationship between migration, breeding latitude, and CPP, we held two closely related songbird populations in a common environment. One population is resident ( Junco hyemalis carolinensis ), the other winters in sympatry with the residents but migrates north to breed ( Junco hyemalis hyemalis ). We gradually increased photoperiod and measured indices of readiness to migrate (fat score, body mass) and breed (cloacal protuberance volume, baseline testosterone, and gonadotropin releasing hormone challenged testosterone). To estimate breeding latitude, we measured hydrogen isotopes in feathers grown the preceding year. As we predicted, we found a higher CPP in migrants than residents, and a higher CPP among migrants deriving from higher as opposed to lower latitudes. Migrants also terminated breeding earlier than residents, indicating a shorter breeding season. To our knowledge, this is a first demonstration of latitudinal variation in CPP-dependent reproductive timing in bird populations that co-exist in the non-breeding season but breed at different latitudes. We conclude that bird populations appear to exhibit local adaptation in reproductive timing by relying on differential CPP response that is predictive of future conditions on the breeding ground.

Indiana↗
USGS1997

A citywide breeding bird survey for Washington, D.C.

`DC Birdscape' was initiated in 1993 to systematically count the birds occurring throughout Washington D.C. during the breeding season. It involved a coordinated planning effort and partnership between the Audubon Naturalist Society, the National Park Service, and the National Biological Survey, and engaged the participation of more than 100 volunteers. A method for rapidly assessing the status of bird populations over a large area was developed and incorporated into a Geographic Information System to allow a multidimensional analysis of species presence and abundance across a variety of urban land use areas. A total of 91 species were observed, with an estimated total number of 115, making Washington D.C. almost as `bird rich' as nearby suburban counties. Data from the study clearly indicate that avian species are not randomly distributed throughout the Washington D.C. metropolitan area, and show affinity, at least in part, to some of the most broadly recognized land use patterns that are commonly used to zone and classify urban areas under development schemes. This study represents a prototype that will allow efficient and economical monitoring of urban bird populations.

Washington, D.C.↗
USGS2020

Forest bird trends within Haleakala National Park

In 2017, the comprehensive east Maui bird surveys allowed for an update in status and evaluation of trends in bird populations within Haleakalā National Park. This report describes a finer-scale analysis of the park lands, distinguishing between the upper Kīpahulu Valley plus adjacent high-elevation areas compared to the rest of the park. I report abundance estimates and assess trends for six native and three non-native bird species within the park. Overall abundance estimates are consistent with those in previous reports, but there is some evidence for different densities between the two areas of the park, and relative densities of some species may vary from survey to survey. With two possible exceptions (native ‘apapane and non-native red-billed leiothrix), recent trends indicate that bird populations are in decline.

Hawai'i↗
USGS2025

Foundational science in flight—USGS bird programs support conservation, culture, and a thriving U.S. economy

Birds are vital to our economy, ecosystems, and cultural heritage. Investing in bird conservation benefits communities, businesses, and working lands while reinforcing our nation’s legacy of stewardship and biodiversity. By valuing birds, we ensure a richer, healthier, and more vibrant future for all Americans. The USGS leads two national bird monitoring programs Thriving bird populations contribute over $ 100 billion in related purchases to the U.S. economy annually, helping to support 1.4 million jobs and $ 90 billion in labor-related income. Across our nation, Federal and State wildlife agencies, Flyway Councils, non-governmental organizations, and more consider data from the U.S. Geological Survey’s (USGS) Bird Banding Laboratory (BBL) and Breeding Bird Survey (BBS) to be critical to meeting their mandates to set healthy harvest levels and in identifying species of conservation need. However, without stable and sufficient resources for the BBL and BBS, the capacity to monitor and address the rapidly evolving needs of migratory bird populations is at risk, jeopardizing the foundation of collaborative conservation efforts across North America.

Fact Sheet↗