Search USGSSearch

SEARCH · Search USGS

Results for “American Wildlife”

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 199 records · Page 11Linked to original sources

Is disease an important mortality factor for Pacific herring?

Marine pelagic forage fishes, including sardines, anchovies, and herring, undergo large oscillations in population abundance. Although over-fishing can have a dramatic impact in reducing population size, this anthropogenic perturbation cannot fully account for all population declines because natural oscillations in marine pelagic fish biomasses occurred prior to the onset of commercial fishing. Among the herring metapopulation in Puget Sound / Straight of Georgia, the mean estimated annual mortality, exclusive of commercial fishing, increased from 20% in the late 1970’s and early 1980’s to 64-87% during 1996-1999. This natural mortality affects primarily the older age cohorts and resulted in recent decreased median ages of adult herring from age 4-6 cohorts to age 2-3 cohorts that die prior to iteroparous spawning. Surveys of wild herring from the region indicate that the protozoan parasite Ichthyophonus sp., is currently ubiquitous among Pacific herring populations in Washington and British Columbia, and prevalence of infection increase directly with herring age, from 12% among juveniles to 58% among the underrepresented age 6+ cohorts. Ichthyophonus can be highly pathogenic to immunologically naïve Pacific herring, causing 80% mortality 2 mo. after exposure in the laboratory. Current laboratory-based studies are underway to determine whether natural Ichthyophonus infections are terminal for the host, and whether these infections account for the decreasing median age of wild Pacific herring populations in recent years.

American Association of Wildlife Veterinarians

An evaluation of inorganic toxicity reference values for use in assessing hazards to American robins ( Turdus migratorius )

When performing screening-level and baseline risk assessments, assessors usually compare estimated exposures of wildlife receptor species with toxicity reference values (TRVs). We modeled the exposure of American robins ( Turdus migratorius ) to 10 elements (As, Cd, Cr, Cu, Hg, Mn, Pb, Se, Zn, and V) in spring and early summer, a time when earthworms are the preferred prey. We calculated soil benchmarks associated with possible toxic effects to these robins from 6 sets of published TRVs. Several of the resulting soil screening-level benchmarks were inconsistent with each other and less than soil background concentrations. Accordingly, we examined the derivations of the TRVs as a possible source of error. In the case of V, a particularly toxic chemical compound (ammonium vanadate) containing V, not normally present in soil, had been used to estimate a TRV. In the cases of Zn and Cu, use of uncertainty values of 10 in estimating TRVs led to implausibly low soil screening values. In the case of Pb, a TRV was calculated from studies demonstrating reductions in egg production in Japanese quail ( Coturnix coturnix japonica ) exposed to Pb concentrations well below than those causing toxic effects in other species of birds. The results on quail, which were replicated in additional trials, are probably not applicable to other, unrelated species, although we acknowledge that only a small fraction of all species of birds has been tested. These examples underscore the importance of understanding the derivation and relevance of TRVs before selecting them for use in screening or in ecological risk assessment.

Integrated Environmental Assessment and Management

Ecosystems science: Genes to landscapes

Bountiful fisheries, healthy and resilient wildlife, flourishing forests and vibrant grasslands are coveted resources that benefit all Americans. U.S. Geological Survey (USGS) science supports the conservation and management of the Nation’s fish and wildlife, and the landscapes they inhabit. Our biological resources—ecosystems and the wild things that live in them—are the foundation of our conservation heritage and an economic asset to current and future generations of Americans. The USGS Ecosystems Mission Area, the biological research arm of the Department of the Interior (DOI), provides science to help America achieve sustainable management and conservation of its biological resources. This work is done within the broader mission of the USGS—to serve the Nation with science that advances understanding of our natural resources, informs land and water stewardship, and helps safeguard communities from natural and environmental hazards. The Ecosystems Mission Area provides research, technical assistance, and education conducted by Cooperative Research Units and Science Centers located in nearly every State. The quality of life and economic strength in America hinges on healthy ecosystems that support living things and natural processes. Ecosystem science better enables society to understand how and why ecosystems change and to guide actions that can prevent damage to, and restore and sustain ecosystems. It is through this knowledge that informed decisions are made about natural resources that can enhance our Nation’s economic and environmental well-being.

Fact Sheet

SiMPL wildlife magnets: A camera trap tool for detecting all creatures great and small

We created the SiMPL wildlife magnet—a baited camera trap design that allows passive monitoring of wildlife, particularly small- to medium-sized mammals. The SiMPL wildlife magnet is inexpensive and easy to construct. To evaluate its effectiveness, we conducted a two-year case study using 9 camera stations along an elevation gradient in the White Mountains of the northeastern United States. We examined how the detection probability of mammal species changed with the inclusion of a SiMPL wildlife magnet using data from pre-and post-establishment. We found a significant increase in community-level detection probability with the use of SiMPL wildlife magnets and for individual species, including red squirrels ( Tamiasciurus hudsonicus ), American marten ( Martes americana ), and fisher ( Pekania pennanti ). Moreover, we were able to capture more species with SiMPL wildlife magnets than without, including flying squirrels ( Glaucomys spp.), various rodents ( Cricetidae spp.), black bears ( Ursus americanus ), moose ( Alces alces ), owls, and other birds. The SiMPL wildlife magnet is an effective, low-cost method for surveying wildlife communities, especially rodents and mesocarnivores. It addresses the limited field of view presented by other techniques for capturing small mammals on camera traps and enables efficient collection of phenology data, including vegetation and snowpack. This tool has several applications, including monitoring species' responses to management practices and global change.

Ecology and Evolution

Assessing conservation tools for an at-risk shorebird: Feasibility of headstarting for American Oystercatchers Haematopus palliatus

Management of threatened and endangered populations of wildlife increasingly relies upon active intervention such as predator control, habitat manipulation, and ex situ breeding or care. One tool that has received consideration for the management of declining or threatened avian populations is headstarting, or the artificial incubation of eggs and subsequent placement of newly hatched chicks in original or foster nests. We assessed the feasibility of implementing a headstarting program for the American Oystercatcher Haematopus palliatus , a species of high conservation concern in the eastern USA. Annual productivity is often low and lost during incubation, suggesting artificial incubation could enhance annual productivity. We used a control-impact approach to assign nests as either control or headstart and measured daily survival rate, success of parents accepting headstarted chicks, attendance patterns and behaviours of parents, and chick survival. We also implemented a transparent scoring process to rate the success of each step and the overall program. Daily survival rates of nests were significantly higher at headstart compared to control nests, and parents continued to incubate when eggs were well secured at nest sites. Attendance patterns and behaviour did not differ between headstart and control parents, and parents readily accepted healthy chicks whether they were returned to original or foster nests. Chick survival and subsequently annual productivity were, however, not higher at headstart compared to control nests suggesting that although we were able to enhance nest survival, low chick survival was still limiting annual productivity. Ultimately, headstarting may be most appropriate for American Oystercatchers where productivity is lost primarily to flooding, predation, or disturbance during the incubation stage but not during the chick-rearing stage. If, for example, high rates of nest loss are due to predators that also may prey upon chicks, then headstarting may not be an effective conservation tool.

Bird Conservation International

Avian vacuolar myelinopathy: a newly recognized fatal neurologic disease of eagles, waterfowl, and other birds

Wildlife biologists and health specialists have been frustrated by a long list of negative findings in their AVM investigations, however studies continue to provide pieces of information to aid the determination of the cause and its source. Available data indicated that AVM may have been present since at least 1990, occurs in at least five states, has been documented during October through April at sites of wintering populations of birds where the exposure apparently occurs, and has killed at least 90 bald eagles. Birds with AVM have difficulty or inability to fly, swim, walk, or perch, but there has been resolution of clinical signs in some affected coots. The list of affected species continues to grow, but remains confined to wild avians, including bald eagle, American coot, great horned owl, killdeer, Canada goose, mallard, ring-necked duck and bufflehead. The effects of the AVM agent on mammals, including human beings, are unknown. A neurotoxicant of manmade or natural origin is the suspected cause of AVM because no infectious disease agents, such as viruses, bacteria, parasites and prions, have been found, and the lesion and epizootiology of AVM resemble those of toxicoses. Additionally it is documented, experimentally, that exposure to raptors can occur through ingestion of infected coots. Collaborative studies will continue in the effort to identify the cause of AVM, its geographic distribution, and the range of species susceptibility. Hopefully, this information can be used to identify measures that might be taken to reduce the impact of AVM on the wildlife resource. Multiple agencies, institutions, and individuals must rely on each other's expertise in the multidisciplinary approach to this problem, persevere in their efforts and take advantage of serendipity that presents itself during investigations of this newly recognized cause of wild bird mortality.

Arkansas, Georgia, North Carolina, South Carolina

Habitat rehabilitation in the Detroit River area of concern

Loss and degradation of fish and wildlife habitat is a long-standing issue in the Detroit River. The Detroit River Remedial Action Plan helped agencies and stakeholder groups reach agreement on impaired beneficial uses, including loss of fish and wildlife habitat, and helped mobilize all stakeholders to rehabilitate habitat. Many organizations played key roles, including the Detroit River Public Advisory Council, Detroit River Canadian Cleanup, State of the Strait Conferences, American and Canadian Heritage River Initiatives, Detroit River International Wildlife Refuge, and Western Lake Erie Watersheds Priority Natural Area. Accomplishments include: 14 habitat restoration projects on both the Canadian and U.S. side of the Detroit River; 53 soft shoreline engineering projects in the watershed; nine fish spawning reefs in the river, common tern habitat in four locations; and many wetland and green infrastructure projects. Based on Detroit River habitat restoration efforts over the last 32 years, the following advice is offered: reach agreement on severity and geographic extent of the problem; practice adaptive management; involve habitat experts up front in project design; establish quantitative targets for project success; ensure sound multidisciplinary technical support; start with demonstration projects; treat habitat projects as experiments; involve citizen scientists in monitoring; measure benefits; communicate and celebrate successes; and promote education and outreach.

Michigan, Ontario

Annotated bibliography of scientific research on new world screwworm ( Cochliomyia hominivorax ) myiasis in wildlife

The New World screwworm ( Cochliomyia hominivorax ; NWS) is a parasitic blowfly that lays its eggs in open wounds of live, warm-blooded animals including livestock, wildlife, and potentially humans. The larvae consume living animal tissue, and if untreated, the infestation can lead to death. Although NWS was eradicated in the United States in 1966, it has been moving northward from its endemic range in South America during the past decade and could seriously threaten the health of U.S. wildlife populations, making detection, treatment, and surveillance of the disease far more difficult across this multi-sector disease system. As the likelihood of NWS reintroduction to the United States increases, veterinarians, wildlife managers, and conservation specialists need to be informed and prepared to respond. The existing knowledge about NWS interactions with wildlife hosts is lacking, especially regarding North American species where the NWS has been eradicated for more than 50 years. To address this knowledge gap, we compiled an annotated bibliography that consolidates key information from the existing literature on NWS infestation in wild animals.

Open-File Report

Oral Sampling of little brown bat (Myotis lucifugus) maternity colonies for SARS-CoV-2 in the Northeast and Mid-Atlantic, USA

T he potential introduction of SARS-CoV-2, the virus responsible for the COVID-19 pandemic, into North American bat populations is of interest to wildlife managers due to recent disease-mediated declines of several species. Populations of little brown bats ( Myotis lucifugus ) have collapsed due to white-nose syndrome (WNS), a disease caused by the introduction and spread of the fungal pathogen Pseudogymnoascus destructans ( Pd ). Throughout much of the United States and southern Canada, large colonies of the species routinely established diurnal roosts in anthropogenic structures, thereby creating the potential for direct human contact and cross-species disease transmission. Given recent declines and the potential for further disease impacts, we collected oral swabs from eight little brown bat maternity colonies to assess the presence and prevalence of SARS-CoV-2 by RT-qPCR analysis. Little brown bat colonies in Maryland ( n = 1), New Hampshire ( n = 1), New Jersey ( n = 2), New York ( n = 1), Rhode Island ( n = 2), and Virginia ( n = 1) were taken during May-August, 2022. From 235 assayed individuals, no bat tested positive for SARS-CoV-2. Our results indicate that little brown bats may not contract SARS-CoV-2 or that the virus persists at undetectable levels in populations of the Mid-Atlantic and Northeast during summer months. Nonetheless, continued monitoring and future work addressing other seasons may still be warranted to conclusively determine infection status.

Maryland, New Hampshire, New Jersey, New York, Rho

Breeding population inventories and measures of recruitment

In this chapter we review the techniques used to measure two important parameters of waterfowl populations, size of breeding population and recruitment. If waterfowl are to be managed toward goals defined in terms of population sizes such as those in the recently signed North American Waterfowl Management Plan (U.S. Fish and Wildlife Service [USFWS] and Canadian Wildlife Service [CWS] 1986), there must be some measure of population size for the various species. Waterfowl managers usually measure population size during the breeding season, although for some species and in some areas winter inventories may be used. Population size is a function of natality and mortality. Other chapters in this volume deal in detail with the biology of those processes. This chapter discusses procedural aspects of measurement and reviews some of the operational systems that have been used to estimate population size and recruitment, especially in North America.

Book chapter

Canvasback ducks

Canvasbacks ( Aythya valisineria ) are unique to North America and are one of our most widely recognized waterfowl species. Unlike other ducks that nest and feed in uplands, diving ducks such as canvasbacks are totally dependent on aquatic habitats throughout their life cycle. Canvasbacks nest in prairie, parkland, subarctic, and Great Basin wetlands; stage during spring and fall on prairie marshes, northern lakes, and rivers; and winter in Atlantic, Pacific, and Gulf of Mexico bays, estuaries, and some inland lakes. They feed on plant and animal foods in wetland sediments. Availability of preferred foods, especially energy-rich subterranean plant parts, is probably the most important factor influencing geographic distribution and habitat use by canvasbacks. In spite of management efforts that have included restrictive harvest regulations and frequent hunting closures in all or some of the flyways (Anderson 1989), canvasback numbers declined from 1955 to 1993 and remain below the population goal (540,000) of the North American Waterfowl Management Plan (USFWS and Canadian Wildlife Service 1994). Causes for this apparent decline are not well understood, but habitat loss and degradation, low rates of recruitment, a highly skewed sex ratio favoring males, and reduced survival of canvasbacks during their first year are considered important constraints on population growth.

Book chapter