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At least 1,207 records · Page 67Linked to original sources
USGS1977

Breeding avifauna of the south San Francisco Bay estuary

San Francisco Bay represents one of the largest estuarine areas on the Pacific Coast of North America. Its open waters, tidal flats, tidal marshes and solar evaporation ponds provide critical foraging, resting and breeding habitat for migratory and resident birds. The avifauna of San Francisco Bay has received considerable attention; however, little of it has been directed toward assessing the overall importance of the Bay as a nesting area. Works by Grinnell and Wythe (1927), Grinnell and Miller (1944) and Sibley (1952) are the only comprehensive studies of San Francisco Bay avifauna. These studies, while major contributions, are broad in scope as they relate to the breeding avifauna of the Bay's estuarine areas. Several studies by Johnston (1955, 1956a, b), Marshall (1948a, b), DeGroot (1927, 1931) and Zucca (1954) have concentrated on the breeding biology of individual species; however, much of the marsh reclamation and Bay fill has occurred since. The present breeding status of many resident and migratory birds is poorly known for San Francisco Bay. Included among these are three rare or endangered forms: California Black Rail, California Clapper Rail and California Least Tern. In addition, some species now found in the area represent recent breeding range extensions. This study, undertaken from March to September 1971 and including a few more recent data, presents a quantitative assessment of the present breeding bird populations in the South San Francisco Bay area.

California↗
USGS2012

Preliminary investigations of the winter ecology of Long-billed Curlews in coastal Texas

Since the early 1900s, the distribution of the Long-billed Curlew ( Numenius americanus ) has contracted dramatically in the eastern one-half of its historic range. The species has been designated as a "Bird of Conservation Concern" and focal species by the U.S. Fish and Wildlife Service, a species of concern by several states, and a "Highly Imperiled" species in the U.S. Shorebird Conservation Plan. The uncertain outlook for this species has contributed to a plethora of research on Long-billed Curlews, most of which have focused on breeding and nesting ecology of the species. Gaps remain in information about factors affecting population dynamics on the winter grounds and the linkages between Long-billed Curlew populations on the breeding range, migration routes, and winter range. To begin filling those gaps, a pilot study was done to evaluate (1) curlew use of nocturnal roost sites, (2) use of public outreach to locate curlews and contribute to preliminary assessment of foraging habitat use, (3) six different methods to capture curlews, and (4) movements by curlews on wintering areas. The study area includes the lower Texas coast, which harbors the eastern-most dense populations of Long-billed Curlews in North America. Use of historical winter roost sites was not observed; however, there was documented limited use (up to 150 curlews) of several new roost sites, some of which were used on an intermittent or erratic basis. Reports elicited from the public indicated Long-billed Curlews wintering in coastal Texas often forage in open, grass-covered lots of partially developed residential areas, golf courses, and public parks within urban and suburban zones. Curlews were reported to use these sites in developed areas as far as 100 kilometers inland. Other reports indicated Long-billed Curlews foraging in farm fields, shallow coastal marsh, and on the beaches of Gulf of Mexico barrier islands. The effectiveness of six techniques for capture of Long-billed Curlews was evaluated in the study. Seven curlews were captured and banded with four of six methods attempted. At least one curlew each was captured with (1) noose ropes, (2) baited bow net, (3) Coda Netgun, and (4) whoosh net; no curlews were caught with a cast net or Super Talon netgun. The Coda Netgun proved to be the most effective methodology examined. Captured birds (7) were weighed, measured, and banded. Body masses (mean = 518 grams) were low compared to data previously published on body mass of Long-billed Curlews. There were 22 observations recorded of banded curlews. Resightings confirmed that birds were not harmed during capture. All of the 22 resightings occurred within two kilometers of the banding locations, suggesting that birds remained near their chosen foraging areas. Results from this 1-year pilot study yielded an intriguing combination of findings that warrant further investigation. Observations include reduced numbers of roosting birds along the Texas coast during dry conditions, highly dynamic use of nocturnal roost sites, use of widely divergent habitat types for foraging, low body mass of most captured birds, and apparent fidelity to general feeding areas. Future investigations of this eastern winter population of curlews would benefit from larger sample sizes and monitoring of individual birds.

Texas↗
USGS2006

Use of NEXRAD to study shorebird migration in the Prairie Pothole region: A feasibility study

An essential component of shorebird conservation is identifying, protecting, and managing high-priority stopover sites and migration habitats crucial to the long-term persistence of migrating shorebirds. Because of the tremendous variability in migrant shorebird occurrence patterns in the Prairie Pothole Region of the U.S. (Skagen 1997), it is labor- and cost-intensive to locate the majority of sites used heavily by shorebirds in any one migration period. Because WSR-88D (Weather Surveillance Radar – 1988 Doppler) or NEXRAD (NEXt generation weather RADar) has been useful for locating migrating birds and revealing migration patterns and important roosting sites of some species (e.g., Diehl and others 2003, Gauthreaux and Belser 2003), we undertook a pilot field study to determine wheTHER it also might be feasible to use NEXRAD for locating important stopover sites used by migrating shorebirds in the prairie potholes landscape. Coordinated efforts to advance the applicability of radar technology to bird conservation are underway (Ruth and others 2005).

Open-File Report↗
USGS1992

Geologic studies in Alaska by the U.S. Geological Survey, 1990

This collection of papers continues the annual series of U.S. Geological Survey (USGS) reports on geologic investigations in Alaska. From 1975 through 1988, the series was published as USGS circulars. The first of these appeared under the title "The United States Geological Survey in Alaska: Accomplishments during 1975," and the series continued to the last annual circular entitled "Geologic studies in Alaska by the U.S. Geological Survey during 1987," which reflects a title change made in 1986. This 1990 volume continues the bulletin format started in 1988. As in 1989, this volume separates shorter contributions as Geologic Notes from more extensive Articles. This 1990 volume of 18 Articles and 4 Geologic Notes represents the broad range of USGS research activities carried out in Alaska over the past few years. These studies include topics on mineral and other resources such as gold (Y eend), platinum-group elements (Cathrall and Antweiler), coal (Roberts, Stricker, and Affolter), and petroleum (Howell, Bird, and others). Many other investigations provide background geochemical (Kilburn, Box, and others) and geologic data needed for resource evaluation as well as for determining the general geologic framework of Alaska, as in stratigraphic, sedimentologic, and paleontologic and radiometric age studies (Blodgett, Clough, and others; Box and Elder; Dickinson and Skipp; Marincovich and Moriya; McLean and Stanley; Stanley, Flores, and Wiley; Roeske, Pavlis, and others); geophysics (Sampson, Labson, and Long); structure and tectonic evaluations (Bradley and Kosky; Clendenen, Sliter, and Byrne; Karl; Csejtey; Howell, Johnsson, and others); and geomorphic and late Quaternary studies (Carter and Hillhouse; Galloway, Huebner, and others; McGimsey, Richter, and others; Nelson and Carter). These studies span nearly the entire State from the North Slope and Brooks Range to interior, southwestern, and south-central Alaska (fig. 1). Two bibliographies (White) at the end of the volume list (1) reports about Alaska in USGS publications released in 1990 and (2) reports about Alaska by USGS authors in publications outside the USGS in 1990. A bibliography and index of papers in past USGS circulars that are devoted to geologic research and accomplishments in Alaska (1975 to 1986) is published as USGS Open-File Report 87-420.

Alaska↗
USGS2009

Does influenza A affect body condition of wild mallard ducks, or vice versa?

Low pathogenic avian influenza (LPAI) viruses are well documented to circulate within wild waterfowl populations (Olsen et. al. 2006 ). It has been assumed that these infections are benign with no subsequent effects on life-history parameters. The study by Latorre-Margalef et al. (2009 ; hereafter L.-M. et al. ) represents an important step, as they attempt to test this assumption in wild birds. L.-M. et al. captured migrating mallards ( Anas platyrhynchos ) at a staging area and tested them for the presence of avian influenza A virus (IAV). They related IAV infection status to body mass and duration of time spent on the staging area. Overall, the study is well designed with impressive sample sizes and the analyses are carefully conducted and presented. However, in discussing these results, the authors assume causation based upon correlation and, although they acknowledge the possibility of immunosuppression during migration due to reduced energy stores, they do not discuss it as a possible explanation for their findings. Below, we consider several of the major findings by L.-M. et al. , providing alternative explanations for the results. Because the L.-M. et al. study design is correlational, it is not possible to use their data to distinguish between their interpretations and our alternative explanations.

Proceedings of the Royal Society B: Biological Sci↗
USGS2009

A neotropical migrant bird's dilemma: where to stop for a good meal

To learn how migrating birds determine where to stop and find food, scientists from the U.S. Geological Survey, Northern Arizona University, and The University of Arizona studied the behavior of 28 species of neotropical migrant songbirds - warblers, flycatchers, tanagers, and vireos - along the lower Colorado River from 2001 to 2004. They found that, like interstate travelers greeted by restaurant billboards, songbirds flying over Cibola National Wildlife Refuge, Arizona, relied on the flowering of honey mesquite (Prosopis glandulosa) to detect the availability of insects that they prey on. Understanding where and why migrant birds stop will help land managers better protect key habitats used by these tiny travelers.

Fact Sheet↗
USGS2009

A landscape indicator approach to the identification and articulation of the consequences of land-cover change in the Mid-Atlantic Region, 1973-2001

Landscape indicators, derived from land-use and land-cover data, hydrology, nitrate deposition, and elevation data, were used by Jones and others (2001a) to calculate the ecological consequences of land-cover change. Nitrate loading and physical bird habitat were modeled from 1973 and 1992 land-cover and other spatial data for the Mid-Atlantic region. Utilizing the same methods, this study extends the analysis another decade with the use of the 2001 National Land Cover Dataset. Land-cover statistics and trends are calculated for three time periods: 1973-1992, 1992-2001 and 1973-2001. In addition, high-resolution aerial photographs (1 meter or better ground-sample distance) were acquired and analyzed for thirteen pairs of adjacent USGS 7.5 minute quadrangle maps in areas where distinct positive or negative changes to nitrogen loading and bird habitat were previously calculated. During the entire 30 year period, the data show that there was extensive loss of agriculture and forest area and a major increase in urban land-cover classes. However, the majority of the conversion of other classes to urban occurred during the 1992-2001 period. During the 1973-1992 period, there was only moderate increase in urban area, while there was an inverse relationship between agricultural change and forest change. In general, forest gain and agricultural loss was found in areas of improving landscape indicators, and forest loss and agricultural gain was found to occur in areas of declining indicators related to habitat and nitrogen loadings, which was generally confirmed by the aerial photographic analysis. In terms of the specific model results, bird habitat, which is mainly related to the extent of forest cover, declined overall with forest extent, but was also affected more in the decline of habitat quality. Nitrate loading, which is mainly related to agricultural land cover actually improved from 1992-2001, and in the overall study, mainly due to the conversion of agriculture to forests and urban. The high-resolution imagery analysis was significant in that it confirmed, at a very local level, the specific land-cover changes that were driving the landscape metrics and model results that were calculated from moderate resolution land-cover data and models. These were generally subtle changes in patch size of agriculture, forest, and urban areas, but had substantial effects on bird habitat and nitrogen loadings. This analysis of high-resolution imagery demonstrates and confirms the important ability of moderate-resolution land-cover data to capture significant landscape-level activity that is directly related to specific metrics of ecological significance. It also demonstrates consistent landscape-scale relationships between data derived from high-resolution, moderate-resolution and landscape-model sources. Finally, many of the areas of improvement and decline in bird habitat and nitrogen loadings appear to be potentially regional in nature and likely reflect some local trend in landscape activity. Although the use of ecoregions as sampling units has been criticized in recent years, these results show that basic changes in Level 1 land-cover categories, such as forest and agriculture, may still reflect ecoregional patterns and considerations at some scale of mapping and analysis. This is a potentially important area for future landscape-indicator research. This and other follow-on research opportunities are discussed.

Open-File Report↗
USGS2006

Vascular Plant and Vertebrate Inventory of Gila Cliff Dwellings National Monument

Executive Summary This report summarizes the results of the first comprehensive biological inventory of Gila Cliff Dwellings National Monument (NM) in western New Mexico. This project was part of a larger effort to inventory plants and vertebrates in eight National Park Service units in Arizona and New Mexico. Our surveys address many of the objectives that were set forth in the monument's natural resource management plan almost 20 years ago, but until this effort, those goals were never accomplished. From 2001 to 2003 we surveyed for vascular plants and vertebrates (amphibians, reptiles, birds, and mammals) at Gila Cliff Dwellings NM to document presence of species within the boundaries of the monument. For all taxonomic groups that we studied, we collected 'incidental' sightings on U.S. Forest Service lands adjacent to the monument, and in a few cases we did formal surveys on those lands. Because we used repeatable study designs and standardized field techniques, these inventories can serve as the first step in a biological monitoring program for Gila Cliff Dwellings NM and surrounding lands. We recorded 552 species at Gila Cliff Dwellings NM and the surrounding lands (Table 1). We found no non-native species of reptiles, birds, or mammals, one non-native amphibian (American bullfrog), and 33 non-native plants. Particularly on lands adjacent to the monument we found that the American bullfrog was very abundant, which is a cause for significant management concern. Species of non-native plants that are of management concern include red brome, bufflegrass, and cheatgrass. For a park unit of its size and geographic location, we found the plant and vertebrate communities to be fairly diverse; for each taxonomic group we found representative species from a wide range of taxonomic orders and/or families. The monument's geographic location, with influences from the Rocky Mountain, Chihuahuan Desert, and Madrean ecological provinces, plays an important role in determining the species richness at the monument. Also important is the wide range of conditions at the site. The diversity of plants results from a wide variety of soil types and aspects (from the cool, moist Cliff Dweller Canyon to dry mesa slopes) and an abundance of water from the West Fork of the Gila River. In turn, the vertebrate communities respond to this diversity of vegetation, topography, and microsites. For example, for each taxonomic group we found species that were only associated with a single community type, most often the riparian areas along the West and Middle forks of the Gila River. We found cause for significant concern with regard to loss of species in the last few decades. One species of amphibian (Chiricahua leopard frog) is certainly extirpated from the area. Three other species of amphibians (Mexican spadefoot, Woodhouse's toad, and red-spotted toad), reported as being 'common' in the area in 1971, were not found during our surveys. In addition, we did not find three species of rodents that were found in 1965: silky pocket mouse, Ord's kangaroo rat, and southern grasshopper mouse. The monument's aquatic vertebrate component, in particular, may be at a critical juncture whereby other species, such as gartersnakes, may be poised for extirpation. Declining abundance of native fish species has been demonstrated from long-term monitoring of these communities along the Middle Fork of the Gila River. This report includes lists of species recorded by us or species likely to be recorded with additional survey effort. It also includes management implications from our work - how the monument staff might better maintain or enhance the unique biological resources of the monument. This study is the first step in a long-term process of compiling information on the biological resources of the monument and its surrounding areas. We recommend additional inventory and monitoring studies and identify components of our effort that could be improved upon

Open-File Report↗
USGS2008

Yellow-billed Cuckoo Distribution, Abundance, and Habitat Use Along the Lower Colorado River and Its Tributaries, 2007 Annual Report

This 2007 annual report details the second season of a 2-year study documenting western yellow-billed cuckoo (Coccyzus americanus occidentalis) distribution, abundance, and habitat use throughout the Lower Colorado River Multi-Species Conservation Program boundary area. We conducted cuckoo surveys at 40 sites within 14 areas, between 11 June and 9 September 2007. The 169 surveys across all sites yielded 163 yellow-billed cuckoo detections. Cuckoos were detected at 25 of the 40 sites, primarily at the Bill Williams River National Wildlife Refuge (NWR) study area (n = 139 detections; 85 percent of all detections). Detections declined slightly through the cuckoo breeding season, with most detections occurring in the first and second survey periods (n = 92; 54 percent). We detected breeding activity only at the Bill Williams River NWR, where we confirmed 27 breeding events, including two nesting observations. However, the breeding status of most detected birds was unknown. We used playback broadcast recordings to survey for yellow-billed cuckoos. Compared to simple point counts or surveys, this method increases the number of detections of this secretive, elusive species. It has long been suspected that cuckoos have a fairly low response rate, and that the standard survey method of using broadcast recordings might fail to detect all birds present in an area. In 2007, we found that the majority (84 percent) of cuckoo detections were solicited through broadcast at all study sites. The number of solicited detections was highest during the first survey period and declined as the breeding season progressed, while the number of unsolicited detections (cuckoos heard calling before broadcast was initiated) remained fairly constant through the first, second, and third survey periods. The majority (66 percent) of cuckoo detections, solicited or unsolicited, were aural, 23 percent were both heard and seen, and 11 percent were visual detections only. We also found that 50 percent of all responses by cuckoos were evenly split between the first and second broadcasts at sites with >10 detections, while 45 percent of responses occurred after a single broadcast at the sites with <10 detections. We refined our collection of vegetation data in 2007 and found that across the entire study area the dominant tree species were tamarisk (Tamarix spp.), willow (Salix spp.), and cottonwood (Populus spp.). The smallest size class (<8 cm diameter at breast height) trees were the most common and were dominated by tamarisk, but cottonwood and willows were well represented in the larger size classes. Sites that were occupied by yellow-billed cuckoos generally had higher canopies, denser cover in the upper layers of the canopy, and sparse shrub layers compared to unoccupied sites that consistently had higher densities of woody species. As most occupied sites were within the Bill Williams River NWR and most unoccupied sites were at Grand Canyon National Park/Lake Mead National Recreation Area, vegetation characteristics at these study areas drove the cuckoo distribution patterns we observed in 2007. However, there was a range of habitat conditions in locations that were used by yellow-billed cuckoos across the entire lower Colorado River Multi-Species Conservation Program study area. We measured microclimate variables (temperature, relative humidity, soil moisture) at occupied and unoccupied sites, and found that, across the entire study area, occupied sites were consistently cooler during the day and more humid during the day and night compared to unoccupied sites, but that soil moisture did not differ between occupied and unoccupied sites. While most cuckoo detections occurred at Bill Williams River NWR, with generally cooler and more humid conditions, cuckoos were also detected at study areas that had hotter and dryer microclimate conditions. We did not find any relationship of canopy cover characteristics to temperature or soil moisture, suggesting

Open-File Report↗
USGS1981

Birds of the St. Croix River valley: Minnesota and Wisconsin

The St. Croix River Valley encompasses nearly 11,550 km2 in east-central Minnesota and northwestern Wisconsin. A wide range of habitats are available for birds including upland oak, lowland deciduous, maple-basswood, lowland and upland coniferous forests, natural basin wetlands, and grasslands. Situated in the north-central region of the United States, the valley is a biological 'crossroads' for many species. Because of the mixed affinities of plant communities, the valley includes the northern and southern range limits for a number of species. Also, because the valley lies near the forest-prairie transition zone, many typical western breeding species (e.g. pintail, western meadowlark, yellow-headed blackbird) breed in proximity to typical eastern species such as tufted titmouse, eastern meadowlark, and cardinal. From 1966 to 1980, I conducted extensive surveys of avian distribution and abundance in the St. Croix River Valley. I have supplemented the results of these surveys with published and unpublished observations contributed by many ornithologists. These additional data include compilations from Christmas Bird Counts sponsored by the National Audubon Society and from the Breeding Bird Survey coordinated by the U.S. Fish and Wildlife Service. Three hundred fourteen species have been recorded in the study area; data are presented on the migration period, nesting season distribution, winter distribution, relative abundance, and habitat use of each species. Recognizing the uniqueness of the area, and its importance not only to wildlife but also to man, the U.S. Congress designated the St. Croix a National Scenic Riverway. This action provided a considerable degree of protection to lands along and directly adjacent to the river. Unfortunately, no similar legal measure exists to protect lands away from the river. With the exception of the northern quarter of the St. Croix River Valley, agricultural interests have made significant inroads into the habitat base. The continuing expansion of the nearby Minneapolis-St. Paul metropolitan region has degraded or destroyed many woodlots, upland fields, and wetlands. In numerous instances, degradation of natural habitats has influenced the abundance and distribution of bird species. Because of these changes, both the Federal government and State Departments of Natural Resources have listed several species in various categories based on their current status. In the St. Croix River Valley, seven species are endangered, eight are threatened, and 29 are watch or priority status in either or both states. Data presented in this report are of value to land managers, land use specialists, and ornithologists, in assessing current and projected habitat alterations on the avifauna of this valley. The St. Croix River bisects a large region of western Wisconsin and east central Minnesota that exhibits a wide range of habitat types. This region supports not only birds, but many mammals, fishes, reptiles and amphibians, and several thousand species of vascular and nonvascular plants. The river itself is relatively clean through most of its course, and its natural flow is interrupted by only two small dams. Because the river lies within a 1-day drive of nearly 10 million people (Waters 1977), use of the area for recreational purposes is extremely heavy. Recreational pursuits include sunbathing, boating, and wild river kayaking in the summer, and ice fishing and cross-country skiing in the winter. The large number of unique and highly fragile habitats that exist there may never be compatible with the uses and abuses of the land that go with expanding human populations. Through the efforts of a number of citizens concerned with the quality of their environment and the foresightedness of several local, State, and Federal legislators, a portion of the upper St. Croix River Valley (hereafter termed 'the Valley') was established as a National Wild and Scenic River. Through establishment of t

North American Fauna↗
USGS2018

Making do with less: Must sparse data preclude informed harvest strategies for European waterbirds?

The demography of many European waterbirds is not well understood because most countries have conducted little monitoring and assessment, and coordination among countries on waterbird management has little precedent. Yet intergovernmental treaties now mandate the use of sustainable, adaptive harvest strategies, whose development is challenged by a paucity of demographic information. In this study, we explore how a combination of allometric relationships, fragmentary monitoring and research information, and expert judgment can be used to estimate the parameters of a theta-logistic population model, which in turn can be used in a Markov decision process to derive optimal harvesting strategies. We show how to account for considerable parametric uncertainty, as well as for different management objectives. We illustrate our methodology with a poorly understood population of taiga bean geese ( Anser fabalis fabalis ), which is a popular game bird in Fennoscandia. Our results for taiga bean geese suggest that they may have demographic rates similar to other, well-studied species of geese, and our model-based predictions of population size are consistent with the limited monitoring information available. Importantly, we found that by using a Markov decision process, a simple scalar population model may be sufficient to guide harvest management of this species, even if its demography is age-structured. Finally, we demonstrated how two different management objectives can lead to very different optimal harvesting strategies, and how conflicting objectives may be traded off with each other. This approach will have broad application for European waterbirds by providing preliminary estimates of key demographic parameters, by providing insights into the monitoring and research activities needed to corroborate those estimates, and by producing harvest management strategies that are optimal with respect to the managers’ objectives, options, and available demographic information.

Ecological Applications↗
USGS2004

Species Conservation and Management: Case Studies

This edited volume is a collection of population and metapopulation models for a wide variety of species, including plants, invertebrates, fishes, amphibians, reptiles, birds, and mammals. Each chapter of the book describes the application of RAMAS GIS 4.0 to one species, with the aim of demonstrating how various life history characteristics of the species are incorporated into the model, and how the results of the model has been or can be used in conservation and management of the species. The book comes with a CD that includes a demo version of the program, and the data files for each species.

Book↗
USGS1975

California condor plumage and molt as field study aids

An analysis is made of the reliability of plumage and molt characteristics of the California condor for estimating age and identifying individual birds. Neither character seems sufficiently reliable to use in more than a general way.

California Fish and Game↗
USGS2003

Biomagnification factors (fish to osprey eggs from Willamette River, Oregon, U.S.A.) for PCDDS, PCDFS, PCBS, and OC pesticides

A migratory population of 78 pairs of Osprey ( Pandion haliaetus ) nesting along the Willamette River in westernOregon was studied in 1993. The study was designed to determinecontaminant concentrations in eggs, contaminant concentrationsin fish species predominant in the Ospreys diet, andBiomagnification Factors (BMFs) of contaminants from fish specieseaten to Osprey eggs. Ten Osprey eggs and 25 composite samplesof fish (3 species) were used to evaluate organochlorine (OC)pesticides, polychlorinated biphenyls (PCBs), polychlorinateddibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans(PCDFs). Mercury was also analyzed in fish. Geometric meanresidues in Osprey eggs were judged low, e.g., DDE 2.3 μg g -1 wet weight (ww), Σ PCBs 0.69 μg g -1 , 2,3,7,8-TCDD 2.3 ng kg -1 , and generally well below known threshold values for adverse effects on productivity, and the population was increasing. Osprey egg residue data presentedby River Mile (RM) are discussed, e.g., higher PCDDs were generally found immediately downstream of paper mills and eggsfrom the Willamette River had significantly elevated PCBs and PCDDs compared to reference eggs collected nearby in the CascadeMountains. Prey remains at nest sites indicated that the Largescale Sucker ( Catostomus macrocheilus ) and NorthernPikeminnow ( Ptychocheilus oregonensis ) accounted for an estimated 90.1% of the biomass in the Osprey diet, and composite samples of these two species were collected from different sampling sites throughout the study area for contaminant analyses. With the large percentage of the fishbiomass in the Osprey diet sampled for contaminants (and fisheaten by Ospreys similar in size to those chemically analyzed),and fish contaminant concentrations weighted by biomass intake, a mean BMF was estimated from fish to Osprey eggs for the largeseries of contaminants. BMFs ranged from no biomagnification(0.42) for 2,3,7,8-TCDF to 174 for OCDD. Our findings for themigratory Osprey were compared to BMFs for the resident HerringGull ( Larus argentatus ), and differences are discussed. Webelieve a BMF approach provides some basic understanding ofrelationships between contaminant burdens in prey species offish-eating birds and contaminants incorporated into their eggs,and may prove useful in understanding sources of contaminants inmigratory species although additional studies are needed.

Oregon↗
USGS2024

High genetic diversity, low population genetic structure, strong natal philopatry, and longevity revealed in the Black Swift (Cypseloides niger borealis)

Genetic diversity is a critical cornerstone of biodiversity and is a central goal in management and conservation biology. Such diversity has implications for survivability, adaptability, and resiliency of a species. This study aimed to determine levels of genetic diversity and population genetic structure in the Northern Black Swift ( Cypseloides niger borealis ). This species nests across western North America as far north as Canada and south into Mexico, migrating annually to wintering areas in western Brazil. Colonies occur in isolated areas where appropriate nesting habitat is available, and in many cases, colonies are widely separated from each other. Banding data revealed that adults of this long-lived species return to their same breeding colony annually for many years. Additionally, some females exhibit natal philopatry, returning to and successfully raising offspring at the colony where they were hatched. This allowed us to hypothesize that we might expect some amount of genetic structure in the samples we studied. The life history characteristics of this species suggest that breeding colonies might be more genetically differentiated than other migratory birds that tend to have limited population genetic structure across their ranges. We used newly developed species-specific microsatellite primers to examine levels of genetic diversity and connectivity among 6 Black Swift colonies in the western United States. Levels of genetic diversity were generally high (expected heterozygosity ranging from 0.67 to 0.75) and comparable across 3 breeding sites with sufficient sample sizes ( N > 5). Principal coordinates analysis and STRUCTURE analysis showed no real clustering of individuals in regard to colonies, suggesting one panmictic metapopulation rather than multiple populations that are genetically distinct as we had previously hypothesized based on banding data. This is the first study to elucidate the genetic structure among colonies of Black Swift.

Colorado, Idaho, New Mexico↗
USGS1994

Conservation reserve program: benefit for grassland birds in the northern plains

During the past few decades numbers of some species of upland-nesting birds in North America have declined. Duck species such as mallard (Anas platyrhynchos), northern pintail (A. acuta) and blue-winged teal (A. discors) have declined since the early 1970s and have remained low since 1985 (Caithamer et al. 1993). Some grassland-dependent nonwaterfowl species also have declined since 1966, as indicated by the North American Breeding Bird Survey (BBS) (Robbins et al. 1986). For prairie-nesting ducks, population declines can be attributed mostly to low recruitment, partially as a result of low nest success. Klett et al. (1988) concluded that nest success (probability of ≥1 egg of clutch hatches) in much of the U.S. Prairie Pothole Region was inadequate to maintain populations of the five most common upland-nesting duck species studied, and that predators were the most important cause of nest failure. Over the years, as grassland areas have been converted to cropland, ducks have concentrated their nesting in the remaining areas of available habitat, where predators such as red fox (Vulpes vulpes), striped skunk (Mephitis mephitis) and badger (Taxidea taxus) forage (Cowardin et al. 1983). The reasons for declining populations of grassland nonwaterfowl birds are not clear but the loss of suitable grassland-nesting habitat probably is an important factor. Currently, approximately 95 percent of the land in North Dakota is used for agricultural purposes, of which over 60 percent is used for annual crop production (Haugse 1990). Of the grassland that remains, 95 percent is used for livestock production. This probably had a severe impact on grassland bird species that seek idle grass cover for nesting. The 1985 and 1990 U.S. Farm Bills include provisions under the Food Security Act to fund a cropland-idling program called the Conservation Reserve Program (CRP). Over 36 million acres have been enrolled nationwide in the CRP since 1985 (Osborn 1993), and up to 25 percent of cropland in some counties has been converted primarily to grass. In North Dakota, nearly 3 million acres have been enrolled. Over 90 percent of the CRP plantings in North Dakota are grass and grass-legume mix composed primarily of wheatgrass (Agropyron spp.), smooth brome (Bromus inermis), alfalfa (Medicago saliva) and sweetclover (Melilotus spp.). Mixes of these species have been reported to attract high densities of nesting ducks (Duebbert and Kantrud 1974). According to the CRP provisions, the land must remain idle for the 10-year contract period, with the exception of emergency provisions for haying or grazing. CRP appears to have great potential for benefiting many species of grassland-nesting birds. There have been efforts to document the importance of the CRP to migratory birds in the Upper Great Plains of the U.S. Kantrud (1993) studied duck nest success in CRP cover and concluded that nest success was higher than in planted cover on U.S. Fish and Wildlife Service (FWS) Waterfowl Production Areas (WPAs). Johnson and Schwartz (1993a) measured the use of CRP fields by nonwaterfowl birds and reported that several species have responded positively by colonizing CRP fields. They concluded that CRP has the potential to help reverse the population declines of several species. We investigated the importance of CRP to upland-nesting ducks and certain other grassland-nesting birds. For ducks, we compared nest success in CRP cover with nest success in planted cover on WPAs in the same period (1992-93) and with that of an earlier period (1980-84). For nonwaterfowl, we used BBS data to compare the trends in populations of certain species found in CRP, for the periods 1966-86 (pre-CRP cover establishment) and 1987-92 (post-CRP cover establishment) in North Dakota.

North Dakota, South Dakota↗
USGS2010

Cytochrome P4501A biomarker indication of oil exposure in harlequin ducks up to 20 years after the Exxon Valdez oil spill

Hydrocarbon-inducible cytochrome P4501A (CYP1A) expression was measured, as ethoxyresorufin- O -deethylase (EROD) activity, in livers of wintering harlequin ducks ( Histrionicus histrionicus ) captured in areas of Prince William Sound, Alaska, USA, oiled by the 1989 Exxon Valdez spill and in birds from nearby unoiled areas, during 2005 to 2009 (up to 20 years following the spill). The present work repeated studies conducted in 1998 that demonstrated that in harlequin ducks using areas that received Exxon Valdez oil, EROD activity was elevated nearly a decade after the spill. The present findings strongly supported the conclusion that average levels of hepatic EROD activity were higher in ducks from oiled areas than those from unoiled areas during 2005 to 2009. This result was consistent across four sampling periods; furthermore, results generated from two independent laboratories using paired liver samples from one of the sampling periods were similar. The EROD activity did not vary in relation to age, sex, or body mass of individuals, nor did it vary strongly by season in birds collected early and late in the winter of 2006 to 2007, indicating that these factors did not confound inferences about observed differences between oiled and unoiled areas. We interpret these results to indicate that harlequin ducks continued to be exposed to residual Exxon Valdez oil up to 20 years after the original spill. This adds to a growing body of literature suggesting that oil spills have the potential to affect wildlife for much longer time frames than previously assumed.

Alaska↗
USGS2003

Estimating natal dispersal movement rates of female European ducks with multistate modelling

1. We used up to 34 years of capture-recapture data from about 22 100 new releases of day-old female ducklings and multistate modelling to test predictions about the influence of environmental, habitat and management factors on natal dispersal probability of three species of ducks within the Engure Marsh, Latvia. 2. The mean natal dispersal distances were very similar (c. 0.6-0.7 km) for all three species and were on average 2.7 times greater than breeding dispersal distances recorded within the same study system. 3. We were unable to confirm the kinship hypothesis and found no evidence that young first-nesting females nested closer to their relatives (either mother or sister) than to the natal nest. 4. Young female northern shovelers, like adults, moved from small islands to the large island when water level was high and vice versa when water level was low before the construction of elevated small islands. Movement probabilities between the two strata were much higher for young shovelers than adults, suggesting that young birds had not yet developed strong fidelity to the natal site. Movements of young female tufted ducks , unlike those of shovelers, were not dependent on water level fluctuations and reflected substantial flexibility in choice of first nesting sites. 5. Data for young birds supported our earlier conclusion that common pochard nesting habitats in black-headed gull colonies were saturated during the entire study period. Young females, like the two adult age groups, moved into and out of colonies with similar probability. Fidelity probability of female pochards to each stratum increased with age, being the lowest (0.62) for young (DK) females, intermediate (0.78) for yearlings (SY) and the highest (0.84) for adult (ASY) females. 6. Young female tufted ducks , like adults, showed higher probabilities of moving from islands to emergent marshes when water levels were higher both before and after habitat management. The relationship between the spring water levels and movement was much weaker for young females than for adults. 7. Young female diving ducks exhibited much stronger (compared to adults) asymmetric movement with respect to proximity to water, with higher movement probabilities to near-water locations than away from these locations. 8. Local survival of day-old ducklings during the first year of life was time-specific and very low (means for different strata/states 0.01-0.08) because of high rates of emigration and prefledging mortality.

Journal of Animal Ecology↗