Search USGS⌕ Search

SEARCH · Search USGS

Results for “Bird Observer”

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

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

At least 91 records · Page 5Linked to original sources
USGS2016

Evaluating the effectiveness of wildlife detection and observation technologies at a solar power tower facility

Solar power towers produce electrical energy from sunlight at an industrial scale. Little is known about the effects of this technology on flying animals and few methods exist for automatically detecting or observing wildlife at solar towers and other tall anthropogenic structures. Smoking objects are sometimes observed co-occurring with reflected, concentrated light (“solar flux”) in the airspace around solar towers, but the identity and origins of such objects can be difficult to determine. In this observational pilot study at the world’s largest solar tower facility, we assessed the efficacy of using radar, surveillance video, and insect trapping to detect and observe animals flying near the towers. During site visits in May and September 2014, we monitored the airspace surrounding towers and observed insects, birds, and bats under a variety of environmental and operational conditions. We detected and broadly differentiated animals or objects moving through the airspace generally using radar and near solar towers using several video imaging methods. Video revealed what appeared to be mostly small insects burning in the solar flux. Also, we occasionally detected birds flying in the solar flux but could not accurately identify birds to species or the types of insects and small objects composing the vast majority of smoking targets. Insect trapping on the ground was somewhat effective at sampling smaller insects around the tower, and presence and abundance of insects in the traps generally trended with radar and video observations. Traps did not tend to sample the larger insects we sometimes observed flying in the solar flux or found dead on the ground beneath the towers. Some of the methods we tested (e.g., video surveillance) could be further assessed and potentially used to automatically detect and observe flying animals in the vicinity of solar towers to advance understanding about their effects on wildlife.

California↗
USGS1981

The effects of ingested petroleum on the maphthalene-metabolizing properties of the liver tissue in seawater-adapted mallard ducks (Anas platyrhynchos)

Hepatic mixed function oxidase activities were estimated in seawater-adapted mallard ducks (Anas platyrhynchos) that had been consuming food contaminated with one of five different types of crude oil. After 50 days of exposure to contaminated food, enzyme activities of liver microsomal preparations were assessed in terms of their naphthalenemetabolizing properties in vitro. Although dose-dependent increases in the total hepatic enzyme activities (nmole naphthalene metabolized per minute per unit mass body weight) were observed in birds consuming food contaminated with each type of crude oil, three patterns of response were apparent. Crude oils from South Louisiana and Kuwait stimulated large and significant increases in the specific activity of the enzyme system (nmole naphthalene metabolized per minute per unit mass microsomal protein), whereas little or no increase in either microsomal protein content or relative liver weight were observed. In contrast, two crude oils from Santa Barbara, Calif., induced only small increases in specific activity but significant increases occurred in hepatic microsomal protein concentration and relative liver weight. The crude oil from Prudhoe Bay, Ala., evoked intermediate patterns of response. The possible significance of these data is discussed in relation to the survival of seabirds consuming petroleum-contaminated food and drinking water.

Environmental Research↗
USGS2009

Testing the importance of auditory detections in avian point counts

Recent advances in the methods used to estimate detection probability during point counts suggest that the detection process is shaped by the types of cues available to observers. For example, models of the detection process based on distance-sampling or time-of-detection methods may yield different results for auditory versus visual cues because of differences in the factors that affect the transmission of these cues from a bird to an observer or differences in an observer's ability to localize cues. Previous studies suggest that auditory detections predominate in forested habitats, but it is not clear how often observers hear birds prior to detecting them visually. We hypothesized that auditory cues might be even more important than previously reported, so we conducted an experiment in a forested habitat in North Carolina that allowed us to better separate auditory and visual detections. Three teams of three observers each performed simultaneous 3-min unlimited-radius point counts at 30 points in a mixed-hardwood forest. One team member could see, but not hear birds, one could hear, but not see, and the third was nonhandicapped. Of the total number of birds detected, 2.9% were detected by deafened observers, 75.1% by blinded observers, and 78.2% by nonhandicapped observers. Detections by blinded and nonhandicapped observers were the same only 54% of the time. Our results suggest that the detection of birds in forest habitats is almost entirely by auditory cues. Because many factors affect the probability that observers will detect auditory cues, the accuracy and precision of avian point count estimates are likely lower than assumed by most field ornithologists. ?? 2009 Association of Field Ornithologists.

Journal of Field Ornithology↗
USGS2007

Hierarchical spatial models of abundance and occurrence from imperfect survey data

Many estimation and inference problems arising from large-scale animal surveys are focused on developing an understanding of patterns in abundance or occurrence of a species based on spatially referenced count data. One fundamental challenge, then, is that it is generally not feasible to completely enumerate ('census') all individuals present in each sample unit. This observation bias may consist of several components, including spatial coverage bias (not all individuals in the Population are exposed to sampling) and detection bias (exposed individuals may go undetected). Thus, observations are biased for the state variable (abundance, occupancy) that is the object of inference. Moreover, data are often sparse for most observation locations, requiring consideration of methods for spatially aggregating or otherwise combining sparse data among sample units. The development of methods that unify spatial statistical models with models accommodating non-detection is necessary to resolve important spatial inference problems based on animal survey data. In this paper, we develop a novel hierarchical spatial model for estimation of abundance and occurrence from survey data wherein detection is imperfect. Our application is focused on spatial inference problems in the Swiss Survey of Common Breeding Birds. The observation model for the survey data is specified conditional on the unknown quadrat population size, N(s). We augment the observation model with a spatial process model for N(s), describing the spatial variation in abundance of the species. The model includes explicit sources of variation in habitat structure (forest, elevation) and latent variation in the form of a correlated spatial process. This provides a model-based framework for combining the spatially referenced samples while at the same time yielding a unified treatment of estimation problems involving both abundance and occurrence. We provide a Bayesian framework for analysis and prediction based on the integrated likelihood, and we use the model to obtain estimates of abundance and occurrence maps for the European Jay (Garrulus glandarius), a widespread, elusive, forest bird. The naive national abundance estimate ignoring imperfect detection and incomplete quadrat coverage was 77 766 territories. Accounting for imperfect detection added approximately 18 000 territories, and adjusting for coverage bias added another 131 000 territories to yield a fully corrected estimate of the national total of about 227 000 territories. This is approximately three times as high as previous estimates that assume every territory is detected in each quadrat.

Ecological Monographs↗
USGS1974

Effects of radio packages on wild ducks

A total of 211 wild, free-flying mallards ( Anas platyrhynchos ) and wood ducks ( Aix sponsa ) were equipped with breast-mounted radio packages during the breeding seasons of 1968-72. Known predation loss was 7.6 and 12.0 percent for mallards and wood ducks respectively, 60 percent occurred within 3 weeks of instrumentation. The highest predation rate for mallards was 0.0048 kills per tracking day and 0.0136 for wood ducks. A higher direct recovery rate for instrumented birds (19.5 percent) than noninstrumented birds (8.1 percent) was probably due to the novelty of the transmitter to hunters. Departure patterns and locations of direct recoveries were similar between radio-equipped and normal-banded birds. Among female wood ducks with radios, recovery rates were lower than expected. Hunters indicated that 84 percent of the instrumented ducks recovered were in good or excellent condition. Recaptures of ducks as long as 1 year after being equipped with radio packages indicated that feather wear and skin abrasion were not serious. A high rate for feeding on land by instrumented mallards was probably due to our ability to more easily locate and observe these birds in cover. Preening rates were higher for instrumented ducks. As the birds became adjusted to the package, preening decreased and feeding on water increased. Social and breeding behavior of instrumented ducks did not appear to be adversely affected by the radio package.

Minnesota↗
USGS2016

2015-2016 Palila abundance estimates

The palila (Loxioides bailleui) population was surveyed annually during 1998−2016 on Mauna Kea Volcano to determine abundance, population trend, and spatial distribution. In the latest surveys, the 2015 population was estimated at 852−1,406 birds (point estimate: 1,116) and the 2016 population was estimated at 1,494−2,385 (point estimate: 1,934). Similar numbers of palila were detected during the first and subsequent counts within each year during 2012−2016; the proportion of the total annual detections in each count ranged from 46% to 56%; and there was no difference in the detection probability due to count sequence. Furthermore, conducting repeat counts improved the abundance estimates by reducing the width of the confidence intervals between 9% and 32% annually. This suggests that multiple counts do not affect bird or observer behavior and can be continued in the future to improve the precision of abundance estimates. Five palila were detected on supplemental survey stations in the Ka‘ohe restoration area, outside the core survey area but still within Palila Critical Habitat (one in 2015 and four in 2016), suggesting that palila are present in habitat that is recovering from cattle grazing on the southwest slope. The average rate of decline during 1998−2016 was 150 birds per year. Over the 18-year monitoring period, the estimated rate of change equated to a 58% decline in the population.

Technical Report↗
USGS1996

First-time observer effects in the North American Breeding Bird Survey

Currently the operational analysis of Breeding Bird Survey (BBS) data by the National Biological Service accounts for observer differences in estimating the trend for each route, but within-observer differences are not modeled. We tested for the existence of a form of within-observer differences in skill level, namely a change in ability to count birds of a given species after an observer's first year on a given route. An increase in ability could positively bias the trend estimate. Removal of an observer's first year of observation on each route for the period 1966 to 1991 resulted in lower average unweighted trend estimates for 415 of 459 species (90%). These reductions were statistically significant for 213 species (46%). The average reduction in trend was 1.8% change per year (SD = 5.4%). In route-regression analysis, route data are weighted by a measure of precision. Removing first-year observer counts reduced the weighted trend estimate for 275 of 416 species (66%), but differences generally were small.

The Auk↗
USGS2025

Bait trapping of waterfowl increases the environmental contamination of avian influenza virus (AIV)

Highly pathogenic avian influenza virus (HPAIV) H5Nx clade 2.3.4.4b has circulated in North America since late 2021, resulting in higher rates of morbidity and mortality in wild birds than observed in this region before. The objective of this study was to determine whether baiting, which is widely conducted in Canada and the United States as part of waterfowl management practices (e.g., duck banding), influences the occurrence of avian influenza virus (AIV) in wetlands. We used a quasi-experimental design, collecting superficial sediment samples ( n = 336) and fecal samples ( n = 242) from paired baited (treatment) and non-baited (control) sites at 2 wetlands in Saskatchewan, Canada, between August and September 2022. We visited sampling sites 3 times during the sampling period: prior to the commencement of baiting activities ( t0 ), approximately 14 days after t0 ( t1 ), and 24 days after t0 ( t2 ). We screened samples for AIV using real-time reverse-transcriptase polymerase chain reaction (rRT-PCR) targeting the matrix gene and subjected the PCR-positive samples to next-generation sequencing. We used a mixed-effects logistic regression model to estimate the effect of baiting on the odds of AIV positivity in sediment samples, while controlling for clustering by wetland. At control sites, we did not detect evidence for a difference in the odds of AIV detection in sediment at t1 or t2 versus t0 ; however, at baited sites, the odds of AIV detection at t1 were 5.43 (95% CI = 1.99, 14.79) times the odds at t0 and at t2 the odds of AIV detection were 8.73 (95% CI = 3.29, 23.18) times the odds at t0 . We detected HPAIV clade 2.3.4.4b H5N1 in sediment at 1 treatment site following baiting. There was also a trend towards increased fecal AIV positivity and increased fecal and sediment AIV diversity in baited versus non-baited sites; however, there was insufficient power to determine if these findings were statistically significant. Overall, our results indicate that baiting is associated with localized increases in AIV environmental contamination, with baiting potentially creating concentrated areas of AIV accumulation. As such, wetland baiting activities may pose a risk to wildlife population health through the propagation of AIV in wetlands and the waterfowl using those environments and efforts to replace, refine, or reduce this activity may be warranted depending on local ecosystem contexts and cost-benefit analyses.

Saskatchewan↗
USGS2017

Importance of the 2014 Colorado River Delta pulse flow for migratory songbirds: Insights from foraging behavior

The Lower Colorado River provides critical riparian areas in an otherwise arid region and is an important stopover site for migrating landbirds. In order to reverse ongoing habitat degradation due to drought and human-altered hydrology, a pulse flow was released from Morelos Dam in spring of 2014, which brought surface flow to dry stretches of the Colorado River in Mexico. To assess the potential effects of habitat modification resulting from the pulse flow, we used foraging behavior of spring migrants from past and current studies to assess the relative importance of different riparian habitats. We observed foraging birds in 2000 and 2014 at five riparian sites along the Lower Colorado River in Mexico to quantify prey attack rates, prey attack maneuvers, vegetation use patterns, and degree of preference for fully leafed-out or flowering plants. Prey attack rate was highest in mesquite (Prosopis spp.) in 2000 and in willow (Salix gooddingii) in 2014; correspondingly, migrants predominantly used mesquite in 2000 and willow in 2014 and showed a preference for willows in flower or fruit in 2014. Wilson’s warbler (Cardellina pusilla) used relatively more low-energy foraging maneuvers in willow than in tamarisk (Tamarix spp.) or mesquite. Those patterns in foraging behavior suggest native riparian vegetation, and especially willow, are important resources for spring migrants along the lower Colorado River. Willow is a relatively short-lived tree dependent on spring floods for dispersal and establishment and thus spring migrants are likely to benefit from controlled pulse flows.

Arizona, California↗
USGS2004

Seasonal movement and home range of the Mariana Common Moorhen

Adult Mariana Common Moorhens ( Gallinula chloropus guami ) were radio-marked on Guam (n = 25) and Saipan (n = 18) to determine home range, inter- and intraseasonal space use, and movement patterns among the Mariana Islands of Guam, Saipan, Tinian, and Rota. Birds were tracked throughout the dry and wet seasons in 2000 and 2001. During the dry season, no interisland movements were detected and most birds remained at a single wetland. However, some radio-marked adults on Guam (48%) and Saipan (11%) dispersed from their capture site to other wetland sites. Inter-and intraisland movements increased during the wet season. Interisland movement from Saipan to Tinian occurred at the onset of the wet season, although no birds were observed moving off Guam. Radio-marked adults on Guam (71%) and Saipan (70%) dispersed from their capture site to other wetlands. On Guam, moorhens moved farther in the wet season than the dry season. During the wet season frequency of movement among sites was inversely proportional to the average distance between wetlands. Guam moorhens used rivers more often during the wet season. Among nine dispersing adult moorhens captured during the wet season on Fena Reservoir, Guam, 67% returned to Fena Reservoir during the 2001 dry season. Home-range estimates on Guam averaged 3.1 ± 4.8 ha (SD) and did not differ significantly between sexes or seasons. However, during the dry season, females exhibited significantly smaller mean core areas than males.

Mariana Islands↗
USGS2004

Seasonal movement and home range of the Mariana Common Moorhen

Adult Mariana Common Moorhens ( Gallinula chloropus guami ) were radio-marked on Guam ( n = 25) and Saipan ( n = 18) to determine home range, inter- and intraseasonal space use, and movement patterns among the Mariana Islands of Guam, Saipan, Tinian, and Rota. Birds were tracked throughout the dry and wet seasons in 2000 and 2001. During the dry season, no interisland movements were detected and most birds remained at a single wetland. However, some radio-marked adults on Guam (48%) and Saipan (11%) dispersed from their capture site to other wetland sites. Inter-and intraisland movements increased during the wet season. Interisland movement from Saipan to Tinian occurred at the onset of the wet season, although no birds were observed moving off Guam. Radio-marked adults on Guam (71%) and Saipan (70%) dispersed from their capture site to other wetlands. On Guam, moorhens moved farther in the wet season than the dry season. During the wet season frequency of movement among sites was inversely proportional to the average distance between wetlands. Guam moorhens used rivers more often during the wet season. Among nine dispersing adult moorhens captured during the wet season on Fena Reservoir, Guam, 67% returned to Fena Reservoir during the 2001 dry season. Home-range estimates on Guam averaged 3.1 ± 4.8 ha (SD) and did not differ significantly between sexes or seasons. However, during the dry season, females exhibited significantly smaller mean core areas than males.

The Condor↗
USGS2026

Site fidelity of American Oystercatcher Haematopus palliatus in the Cape Romain Region, South Carolina, United States of America

Site fidelity of American Oystercatchers Haematopus palliatus to both high-tide roosts and nesting habitats remains less-well studied than other aspects of their ecology. During high tides, shorebirds concentrate at roosts primarily to sleep and preen, and the loss of high-quality roost habitat has been linked to population declines in several species. Similarly, high-quality nesting habitat reduces risks from predation, flooding, and intraspecific competition. Strong site fidelity provides additional benefits by allowing individuals to become familiar with local resources and threats. We evaluated intra- and inter-annual fidelity to nonbreeding roosts, fidelity to breeding sites, and natal philopatry in a largely undeveloped coastal landscape, the Cape Romain Region in South Carolina. This region supports one of the largest resident breeding populations of American Oystercatchers along the Atlantic coast of the USA and roughly one third of the nation’s wintering population. From 2001–2014, on 713 days, we banded 290 adults and 141 chicks and conducted resighting surveys during spring high tides across beaches and shell rake roosts. Both resident and migrant birds exhibited strong fidelity to nonbreeding sites, while resident birds were even more faithful to their breeding locations. The mean distance between successive nest sites was just over 1 km, compared to an average shift of about 3 km among nonbreeding sites (maximum 43 km). Movements between breeding and nonbreeding sites averaged approximately 4 km. Natal fidelity was also high: birds first observed paired on a breeding site did so on average 5 km from their natal site (maximum 18 km), at a mean age of 5 years. In a region characterized by abundant oyster-reef foraging habitat and low disturbance, these patterns likely reflect the predictability of prey resources and the availability of protected roosts.

South Carolina↗
USGS2008

Apparent tolerance of turkey vultures (Cathartes aura) to the non-steroidal anti-inflammatory drug diclofenac

The nonsteroidal anti‐inflammatory drug diclofenac is extremely toxic to Old World Gyps vultures (median lethal dose ∼0.1–0.2 mg/kg), evoking visceral gout, renal necrosis, and mortality within a few days of exposure. Unintentional secondary poisoning of vultures that fed upon carcasses of diclofenac‐treated livestock decimated populations in the Indian subcontinent. Because of the widespread use of diclofenac and other cyclooxygenase‐2 inhibiting drugs, a toxicological study was undertaken in turkey vultures ( Cathartes aura ) as an initial step in examining sensitivity of New World scavenging birds. Two trials were conducted entailing oral gavage of diclofenac at doses ranging from 0.08 to 25 mg/kg body weight. Birds were observed for 7 d, blood samples were collected for plasma chemistry (predose and 12, 24, and 48 h and 7 d postdose), and select individuals were necropsied. Diclofenac failed to evoke overt signs of toxicity, visceral gout, renal necrosis, or elevate plasma uric acid at concentrations greater than 100 times the estimated median lethal dose reported for Gyps vultures. For turkey vultures receiving 8 or 25 mg/kg, the plasma half‐life of diclofenac was estimated to be 6 h, and it was apparently cleared after several days as no residues were detectable in liver or kidney at necropsy. Differential sensitivity among avian species is a hallmark of cyclooxygenase‐2 inhibitors, and despite the tolerance of turkey vultures to diclofenac, additional studies in related scavenging species seem warranted.

Environmental Toxicology and Chemistry↗
USGS2010

Winter distribution, movements, and annual survival of radiomarked Vancouver Canada geese in southeast Alaska

Management of Pacific Flyway Canada geese ( Branta canadensis ) requires information on winter distribution of different populations. Recoveries of tarsus bands from Vancouver Canada geese ( B. canadensis fulva ) marked in southeast Alaska, USA, &ge;4 decades ago suggested that &ge;83% of the population was non-migratory and that annual adult survival was high (Ŝ = 0.836). However, recovery distribution of tarsus bands was potentially biased due to geographic differences in harvest intensity in the Pacific Flyway. Also, winter distribution of Vancouver Canada geese could have shifted since the 1960s, as has occurred for some other populations of Canada geese. Because winter distribution and annual survival of this population had not recently been evaluated, we surgically implanted very high frequency radiotransmitters in 166 adult female Canada geese in southeast Alaska. We captured Vancouver Canada geese during molt at 2 sites where adults with goslings were present (breeding areas) and 2 sites where we observed nonbreeding birds only. During winter radiotracking flights in southeast Alaska, we detected 98% of 85 females marked at breeding areas and 83% of 70 females marked at nonbreeding sites, excluding 11 females that died prior to the onset of winter radiotracking. We detected no radiomarked females in coastal British Columbia, or western Washington and Oregon, USA. Most (70%) females moved &le;30 km between November and March. Our model-averaged estimate of annual survival (Ŝ = 0.844, SE = 0.050) was similar to the estimate of annual survival of geese marked from 1956 to 1960. Likely <2% of Vancouver Canada geese that nest in southeast Alaska migrate to winter areas in Oregon or Washington where they could intermix with Canada geese from other populations in the Pacific Flyway. Because annual survival of adult Vancouver Canada geese was high and showed evidence of long-term consistency, managers should examine how reproductive success and recruitment may affect the population.

Alaska↗
USGS1987

Feeding methods and efficiencies of selected frugivorous birds

I report on handling methods and efficiencies of 26 species of Paraguayan birds freeding on fruits of Allophyllus edulis (Sapindaceae). A bird may swallow fruits whole (Type I: pluck and swallow feeders), hold a fruit and cut the pulp from the seed with the edge of the bill, swallowing the pulp but not the seed (Type II: cut or mash feeders), or take bites of pulp from a fruit that hangs from the tree or that is held and manipulated against a branch (Type III: push and bite feeders). In terms of absolute amount of pulp obtained from a fruit, and amount obtained per unit time. Type I species are far more efficient than Type II and III species. Bill morphology influences feeding methods but is not the only important factor. Diet breadth does not appear to be significant. Consideration of feeding efficiency relative to the needs of the birds indicates that these species need to spend relatively little time feeding to meet their estimated energetic needs, and that handling time has a relatively trivial effect on the time/energy budges of the bird species observed.

Condor↗
USGS1973

High survival and homing rate of hand-reared wild-strain mallards

In the summer of 1970, 648 (329 males and 319 females) hand-reared wild-strain mallards ( Anas platyrhynchos ) were banded and released at the Arrowwood National Wildlife Refuge, Edmunds, North Dakota. The females were also marked with numbered nasal saddles. Liberation was by the gentle release method, and no special effort was made to isolate or condition the ducklings prior to release. Ducklings were placed in an enclosed pond area at 25 to 45 days of age. Altogether, 627 (97 percent) ducklings reached flight age and dispersed gradually into the wild. All had left the release area by 25 November. First-year band recovery reports indicated that 68 (11 percent) of the birds were shot in 15 states. Their migration pattern was similar to that for immature wild mallards banded in North Dakota in 1970. Eighty-nine (33 percent) of a possible 270 marked females returned to Arrowwood Refuge during 1971. When consideration is given to assumed normal natural mortality and crippling loss, an estimated minimum of 43 percent of the surviving females returned to the release area. Returning birds not observed would raise this figure even higher. This potential homing rate is considerably higher than rates reported for other studies using various strains of mallards. Numerous observations of nests and broods indicated that breeding behavior and nesting success were similar to those of wild mallards in the area. The success of this release is attributed to the inherent capability of hand-reared, wild-strain mallards to revert to their wild behavior, and to the high survival to flight age and first fall migration afforded by the gentle release in a sanctuary area. Indications are that releases of this type under the described conditions can be used to increase the breeding population of mallards in a local area.

North Dakota↗
USGS1943

Hooded warbler in North Dakota

he 1942 warbler migration at Kenmare, Ward County, North Dakota, was rich in species (seventeen) for a locality so far west on the Great Plains. On June 1, near the end of the northward flight, I found a male Hooded Warbler singing in shrubby undergrowth on a wooded coulee slope on the Des Lacs National Wildlife Refuge, about two miles south of Kenmare. The bird was observed at close range for several minutes, both without and with 7-power binoculars. It behaved as in the vicinity of Washington, D. C., where I have been familiar with the species for several years, the song being vigorous and loud and the movements leisurely.

The Auk↗