SEARCH · Search USGS
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.
Because crane chick mortality from disseminated visceral coccidiosis (DVC) at the Patuxent Wildlife Research Center increased in 1988, suggesting that the parasite may be developing a resistance to amprolium, a target animal safety study using coccidiostats, monensin and clazuril, was conducted on 27 subadult sandhill cranes.
Federal and state researchers have been involved in manatee (Trichechus manatus) biomedical health assessment programs for a couple of decades. These benchmark studies have provided a foundation for the development of consistent capture, handling, and processing techniques and protocols. Biologists have implemented training and encouraged multi-agency participation whenever possible to ensure reliable data acquisition, recording, sample collection, publication integrity, and meeting rigorous archival standards. Under a U.S. Fish and Wildlife Service wildlife research permit granted to the U.S. Geological Survey (USGS) Sirenia Project, federal biologists and collaborators are allowed to conduct research studies on wild and captive manatees detailing various aspects of their biology. Therefore, researchers with the project have been collaborating on numerous studies over the last several years. One extensive study, initiated in 2006 has focused on health and fitness of the winter manatee population located in Crystal River, Florida. During those health assessments, capture, handling, and work-up training has been afforded to many of the participants. That study has successfully captured and handled 123 manatees. The data gathered have provided baseline information on manatee health, reproductive status, and nutritional condition. This research initiative addresses concerns and priorities outlined in the Florida Manatee Recovery Plan. The assessment teams strive to continue this collaborative effort to help advance our understanding of health-related issues confronting manatees throughout their range and interlacing these findings with surrogate species concepts.
A free-flying Canada goose ( Branta canadensis interior ), known to be just under a year old, laid a clutch of four eggs at the Patuxent Wildlife Research Center. At least half of the 2-year-old females nest at Patuxent, and almost all of the 3-year-olds nest. As far as we know, this is the first record of nesting by a yearling Canada goose.
We assessed the sampling stability of classification rates in discriminant analysis by using a factorial design with factors for multivariate dimensionality, dispersion structure, configuration of group means, and sample size. A total of 32,400 discriminant analyses were conducted, based on data from simulated populations with appropriate underlying statistical distributions. Simulation results indicated strong bias in correct classification rates when group sample sizes were small and when overlap among groups was high. We also found that stability of the correct classification rates was influenced by these factors, indicating that the number of samples required for a given level of precision increases with the amount of overlap among groups. In a review of 60 published studies, we found that 57% of the articles presented results on classification rates, though few of them mentioned potential biases in their results. Wildlife researchers should choose the total number of samples per group to be at least 2 times the number of variables to be measured when overlap among groups is low. Substantially more samples are required as the overlap among groups increases
An adult bald eagle (Haliaeetus leucocephalus) kept in captivity for nearly 7 yr at the Patuxent Wildlife Research Center, Laurel, Maryland, died suddenly with gross and microscopic lesions characteristic of septicemia. Erysipelothrix rhusiopathiae was isolated from the liver. Fish comprised part of the bird's diet and may have been the source of the organism.
Supporting recovery of federally listed interior least tern (Sternula antillarum athalassos; tern) and piping plover (Charadrius melodus; plover) populations is a desirable goal in management of the Missouri River ecosystem. Many tools are implemented in support of this goal, including habitat management, annual monitoring, directed research, and threat mitigation. Similarly, many types of data can be used to make management decisions, evaluate system responses, and prioritize research and monitoring. The ecological importance of Missouri River recovery and the conservation status of terns and plovers place a premium on efficient and effective resource use. Efficiency is improved when a single data source informs multiple high-priority decisions, whereas effectiveness is improved when decisions are informed by reliable knowledge. Seldom will a single study design be optimal for addressing all data needs, making prioritization of needs essential. Data collection motivated by well-articulated objectives and priorities has many advantages over studies in which questions and priorities are determined retrospectively. Research and monitoring for terns and plovers have generated a wealth of data that can be interpreted in a variety of ways. The validity and strength of conclusions from analyses of these data is dependent on compatibility between the study design and the question being asked. We consider issues related to collection and interpretation of biological data, and discuss their utility for enhancing the role of science in management of Missouri River terns and plovers. A team of USGS scientists at Northern Prairie Wildlife Research Center has been conducting tern and plover research on the Missouri River since 2005. The team has had many discussions about the importance of setting objectives, identifying priorities, and obtaining reliable information to answer pertinent questions about tern and plover management on this river system. The objectives of this presentation are to summarize those conversations and to share insights about concepts that could contribute to rigorous science support for management of this river system.
Salmonellosis caused by Salmonella typhimurium was one of several factors responsible for losses among young herons being held at the Patuxent Wildlife Research Center. The infection was demonstrated in five black-crowned night herons ( Nycticorax nycticorax ), three common egrets ( Casmerodius albus ), two little blue herons ( Florida caerulea ), one cattle egret ( Bubulcus ibis ), one snowy egret ( Leucophoyx thula ) and one Louisiana heron ( Hydranassa tricolor ). The disease was characterized by emaciation, focal liver necrosis, and frequently by a caseo-necrotic enteritis.
Across the western United States, many ungulate herds must migrate seasonally to access resources and avoid harsh winter conditions. Because these migration paths cover vast landscapes (in other words migration distances up to 150 miles [241 kilometers]), they are increasingly threatened by roads, fencing, subdivisions, and other development. Over the last decade, many new tracking studies have been conducted on migratory herds, and analytical methods have been developed that allow for population-level corridors and stopovers to be mapped and prioritized. In 2018, the U.S. Geological Survey assembled a Corridor Mapping Team to provide technical assistance to western states working to map bison, elk, moose, mule deer, and pronghorn migrations using existing Global Positioning System data. Led by the Wyoming Cooperative Fish and Wildlife Research Unit, the team consists of federal scientists, university researchers, and biologists and analysts from participating state agencies. In its first year, the team has worked to develop standardized analytical and computational methods and a workflow applicable to datasets typically collected by state agencies. In 2019, the team completed analyses necessary to map corridors, stopovers, routes and winter ranges in Arizona, Idaho, Nevada, Utah, and Wyoming. A total of 26 corridors, 16 migration routes, 25 stopovers, and 9 winter ranges were mapped across these states and are included in this report. This report and associated data release provide the means for the habitats required for migration to be taken into account by state and federal transportation officials, land and wildlife managers, planners, and other conservationists working to maintain big-game migration in the western states.
Long-term wildlife research and monitoring programs strive to maintain consistent data collections and analytical methods. Incorporating new techniques is important but can render data sets incongruent and limit their potential to discern trends in demographic parameters. Integrated population models (IPMs) can address these limitations by combining data sources that may span different periods into a unified statistical framework while providing a holistic view of population dynamics. We developed an IPM in a Bayesian framework for grizzly bears ( Ursus arctos ) in the Greater Yellowstone Ecosystem. We coupled demographic data with multiple, independent population count data to link annual changes in abundance with vital rates over 4 decades (1983–2023). Abundance increased threefold from an estimated 270 individuals in 1984 to 1030 individuals in 2023. Parameter estimates indicated survival of bears ≥2 years of age was high, contributing to robust population growth during the 1980s (λ = 1.023 [50 % interquartile range = 0.993–1.082]) and 1990s (λ = 1.064 [1.023–1.103]). A slowing of population growth started around 2000 (2000s: λ = 1.030 [0.989–1.068]) and continued into the 2010s (λ = 1.021 [0.985–1.057]), due primarily to reductions in survival of bears <2 years of age. These findings corroborate previous research that identified density-dependent effects as a likely cause. The IPM framework provided greater certainty and understanding regarding the dynamic demographic characteristics of the population and serves as a powerful monitoring tool for this long-lived species. Implementation of the IPM allows timely dissemination of demographic data to help inform adaptive management strategies and policy decisions necessary for the continued management and conservation of this population. This robust and flexible monitoring system allows scientists to investigate the effects of a changing ecosystem on population dynamics, incorporate new data sources and statistical models, and respond to changes in monitoring needs for the population. We highlight the efficacy of the IPM in estimating and tracking demographic parameters for a long-lived species, while accommodating shifts in monitoring techniques and data collections typical of long-term wildlife conservation programs worldwide.
An epizootic of eastern equine encephalitis (EEE) at the Patuxent Wildlife Research Center (PWRC), Laurel, Maryland (USA), in 1989 provided an opportunity to determine if EEE immunization protected whooping cranes ( Grus americana ). Based on seroconversion of 31% of sympatric hatch-year sandhill cranes, Grus canadensis , and a previous 35% case fatality rate in whooping cranes, 17 (37%) of the 46 susceptible whooping cranes should have been exposed to virus and six should have died. As there were no deaths in these birds, the EEE vaccination program appeared to be efficacious in this whooping crane population.
In 1987, an epizootic in cranes at the Patuxent Wildlife Research Center, Laurel, Maryland, USA, caused illness in 80% of 300 captive whooping cranes (Grus americana) and sandhill cranes (Grus canadensis) and death of 15 of these cranes. Gross pathology findings were inconclusive and consisted of dehydration, atrophy of fat, renal insufficiency, and small spleens. Extensive testing resulted in isolation of Fusarium sp. mold from constituents of the grain-based diet. Low levels of two mycotoxins, T2 (1-2 ppm) and deoxynivalenol (0.4 ppm), were isolated from the pelleted feed.
Since 1982 when secondary poisoning of a red-tailed hawk ( Buteo jamaicensis ) was documented following the recommended use of famphur applied topically to cattle, the Patuxent Wildlife Research Center has tested dead birds of prey for poisoning by famphur and other pouron organophosphorus (OP) insecticides. Brain cholinesterase (ChE) activity was first determined, then if ChE was depressed ≥50%, stomach and/or crop contents were evaluated for anti-ChE compounds. This report presents the circumstances surrounding the OP-caused deaths of eight bald eagles ( Haliaeetus leucocephalus ), two red-tailed hawks, and one great horned owl ( Bubo virginianus ) between March 1984 and March 1985. OP poisoning of raptors by pour-on insecticides in the United States is widespread, but its magnitude is unknown.
Kernel methods for estimating home range are being used increasingly in wildlife research, but the effect of sample size on their accuracy is not known. We used computer simulations of 10-200 points/home range and compared accuracy of home range estimates produced by fixed and adaptive kernels with the reference (REF) and least-squares cross-validation (LSCV) methods for determining the amount of smoothing. Simulated home ranges varied from simple to complex shapes created by mixing bivariate normal distributions. We used the size of the 95% home range area and the relative mean squared error of the surface fit to assess the accuracy of the kernel home range estimates. For both measures, the bias and variance approached an asymptote at about 50 observations/home range. The fixed kernel with smoothing selected by LSCV provided the least-biased estimates of the 95% home range area. All kernel methods produced similar surface fit for most simulations, but the fixed kernel with LSCV had the lowest frequency and magnitude of very poor estimates. We reviewed 101 papers published in The Journal of Wildlife Management (JWM) between 1980 and 1997 that estimated animal home ranges. A minority of these papers used nonparametric utilization distribution (UD) estimators, and most did not adequately report sample sizes. We recommend that home range studies using kernel estimates use LSCV to determine the amount of smoothing, obtain a minimum of 30 observations per animal (but preferably a?Y50), and report sample sizes in published results.
A study was conducted on the Arrowwood National Wildlife Refuge in east-central North Dakota to further evaluate a technique for establishing nesting wood ducks ( Aix sponsa ) by releasing propagated birds and installing nest houses. No wood duck nesting had been recorded previously in the area. During May-July 1968, 253 ducklings, hand-reared at the Northern Prairie Wildlife Research Center near Jamestown, North Dakota, were released when 9 to 16 days old into a 0.5-acre enclosure on the refuge, where they grew to flight stage and departed. Seventy-eight nest houses were installed in August on the refuge. About 76 percent of the ducks survived until late September, when southward migration began. The first-year band recovery rate by hunters of 4.7 percent was comparable to that of wild immature wood ducks. Most recoveries occurred between North Dakota and Minnesota in the north and Texas and Louisiana in the south. There were 16 nesting attempts, which produced 175 ducklings, by homing female wood ducks in the boxes in 1969. The number of nesting attempts increased to 34 in 1970, with a production of 311 ducklings.
Hematological and serum chemical constituents of blood were determined for 12 species, including 7 endangered species, of cranes, geese, raptors, and quail in captivity at the Patuxent Wildlife Research Center. Means, standard deviations, analysis of variance by species and sex, and a series of multiple comparisons of means were derived for each parameter investigated. Differences among some species means were observed in all blood parameters except gamma-glutamyl transpeptidase. Although sampled during the reproductively quiescent period, an influence of sex was noted in red blood cell count, hemoglobin, albumin, glucose, cholesterol, serum glutamic oxaloacetic transaminase, Ca, and P. Our data and values reported in literature indicate that most hematological parameters vary among species and, in some cases, according to methods used to determine them. Therefore, baseline data for captive and wild birds should be established by using standard methods, and should be made available to aid others for use in assessing physiological and pathological conditions of these species.
The lethal effects of heptachlor on bobwhites ( Colinus virginianus ) were studied at the Patuxent Wildlife Research Center during 1962 and 1963. A pair of adult birds was placed in each of 32 wire-covered field pens (20 x 50 x 61/2 ft) in May, 1962, and in 36 additional pens in May, 1963. Heptachlor (technical grade on clay granules) was spread in the pens at rates of1/8, 1/4, 1 1/4 and 2 lb/acre. In 1963 the treated pens were thoroughly soaked with a hose before birds were introduced to avoid the possibility of birds pecking granules. Heptachlor at 1 1/4 and 2 lb/acre caused severe mortality among birds introduced successively during the first 15 days after application. Mortality declined rapidly among birds placed in these same pens thereafter and was undetectable after 45 days. Mortality at 1/4 lb/acre was significant only during the first 15 days of the 1962 test. There was no detectable difference in mortality of the sexes. Water applied to the pens followed by fairly heavy rain did not significantly affect mortality.
West Nile virus was introduced into the United States in the vicinity of New York, New York, USA in 1999. The virus has since killed large numbers of birds nationwide, especially, but not limited to, crows ( Corvus brachyrhinchos ). One sandhill crane ( Grus canadensis ) at the Bridgeport Zoo (Bridgeport, Connecticut, USA) reportedly died from West Nile virus, so sandhill cranes and endangered whooping cranes ( Grus americana ), both in the wild and in captive breeding colonies at United States Geological Service (USGS) Patuxent Wildlife Research Center (Laurel, Maryland, USA) were considered at risk. A killed vaccine in sandhill cranes was evaluated by vaccinating and then challenging these cranes with live West Nile virus. No sandhill cranes inoculated with the killed vaccine developed significant titers when compared with unvaccinated controls. No sandhill cranes inoculated with the vaccine and challenged with the virus died from West Nile virus infection. In addition, no unvaccinated challenged sandhill cranes died. However, 2 days postchallenge, vaccinated cranes had significantly less viremia (P < 0.05) than unvaccinated cranes. Seven days postchallenge vaccinated cranes had significantly less cloacal shedding of the virus (P < 0.05) than unvaccinated cranes and significantly less weight loss (P < 0.05) as compared with unvaccinated cranes. Vaccinated sandhill cranes developed significantly higher titers 14 days postchallenge and were viremic for shorter periods of time after challenge than unvaccinated individuals. Unvaccinated challenged cranes had glial cell aggregates in both the brain and brain stem areas, and this was not observed in vaccinated challenged cranes or in vaccinated unchallenged cranes.
A colony of kestrels ( Palco sparverius ) was established at the Patuxent Wildlife Research Center in 1964 in connection with work on pesticides. The kestrels were acquired from the wild, both as nestlings and as full-grown birds, and were housed in several rows of outdoor pens. Each 50 x 20 ft pen was covered with wire netting and had its long sides in common with adjacent pens. During the first two reproductive seasons, untreated parent birds (dosed birds are not included in this paper) ate eggs and young. Cannibalism virtually ceased after the diet was changed from ground beef or horsemeat supplemented with liver, vitamins, and minerals to one containing a finely ground mixture of laboratory rodents, chicken heads, skinned chicken necks, and supplements; hatching success thereafter generally equaled that of a wild population. In 1967, 16 pairs of untreated hawks (3-year-old females) laid clutches averaging 4.9 eggs, hatched 88 percent of their eggs, and fledged 88 percent of their young. In 1968, 10 pairs of this group (4-year-old females) laid clutches averaging 4.9 eggs, hatched 51 percent of their eggs, and fledged 85 percent of their young. Nine yearling pairs (hatched in captivity) laid clutches in 1968 averaging 5.1 eggs, hatched 87 percent of their eggs, and fledged all of their young.