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At least 1,621 records · Page 90Linked to original sources
USGS2005

White-tailed deer ecology and management on Fire Island

Deer populations have grown dramatically on Fire Island National Seashore (FIlS) since 1983. Trend data reveal a dichotomy in deer dynamics. In the eastern half of the island, deer density appears to have stabilized between 25-35 deer/km2. In the western half of the island, deer densities are 3-4 times as high in residential communities. Concomitant with that increase has been a general decline in physical stature of some animals, visible impacts on island vegetation, especially in the Sunken Forest, and a perceived increase in the frequency of human and deer interactions. Intensive research on FIlS has shown that deer occupy relatively predictable home ranges throughout the year, but can and do move up and down the island. Impacts of deer on vegetation are most dramatic in the Sunken Forest. Most obvious are the effects of browsing on the herb layer of the Sunken Forest. The least obvious, but perhaps more significant impact is the stark lack of regeneration of canopy tree species since about 1970, which coincides with the initiation of the deer population irruption. A number of herbs and shrubs have been greatly reduced in the understory, and their propagules from the soil. Deer do not readily transmit the bacterium that causes Lyme disease to other organisms, but deer are important hosts for adult ticks which underscores their importance in the transmission pathway of the disease to humans. Deer on FIlS, while occasionally docile, are still wild animals and should be treated as such. Some animals are relatively unafraid of humans due to the absence of predation and a lack of harassment. This in turn has contributed to a longstanding tradition of feeding deer by many residents and visitors, particularly in western portions of the island. Feeding affects both the behavior and population dynamics of deer inhabiting Fire Island. Recent efforts to reduce deer feeding by visitors and residents have been very effective. Ongoing experiments with Porcine Zona Pellucida immunocontraception demonstrate some promise of this technology as a population management tool.. Success appears to be linked directly to factors affecting access to deer, which vary considerably among treatment locations. Continued high National Park Service visibility among communities in the form of interpretive programs, extension and outreach activities, and continued support of research and monitoring of deer and their effects on island biota are keys to successful resolution of persistent issues.

Technical Report↗
USGS2006

Chemical and ecological health of white sucker (Catostomus Commersoni) in Rock Creek Park, Washington, D.C., 2003?04

Several classes of chemicals that are known or suspected contaminants were found in bed sediment in Rock Creek, including polyaromatic hydrocarbons (PAHs), phthalate esters, organochlorine pesticides, dioxins and furans, trace metals and metalloids (mercury, arsenic, cadmium, chromium, cobalt, copper, lead, nickel, silver, and zinc), and polychlorinated biphenyls (total PCBs and selected aroclors). Concentrations of many of these chemicals consistently exceeded thresholdor chronic-effects guidelines for the protection of aquatic life and often exceeded probable effects levels (PELs). Exceedance of PELs was dependent on the amount of total organic carbon in the sediments. Concurrent with the collection of sediment-quality data, white sucker (Catostomus commersoni) were evaluated for gross-external and internal-organ anomalies, whole-body burdens of chemical contaminants, and gut contents to determine prey. The histopathology of internal tissues of white sucker was compared to contaminant levels in fish tissue and bed sediment. Gut contents were examined to determine preferential prey and thus potential pathways for the bioaccumulation of chemicals from bed sediments. Male and female fish were tested separately. Lesions and other necroses were observed in all fish collected during both years of sample collection, indicating that fish in Rock Creek have experienced some form of environmental stress. No direct cause and effect was determined for chemical exposure and compromised fish health, but a substantial weight of evidence indicates that white sucker, which are bottom-feeding fish and low-order consumers in Rock Creek, are experiencing some reduction in vitality, possibly due to immunosuppression. Abnormalities observed in gonads of both sexes of white sucker and observations of abnormal behavior during spawning indicated some interruption in reproductive success.

Scientific Investigations Report↗
USGS1982

Woodcock brood ecology in Maine

Captures of 102 American woodcock (Philohela minor) broods, including 338 chicks, from 1977 to 1980 provided data on age-related production by breeding females and on growth and survival of chicks. Although broods of second-year females are smaller and hatch at slightly later dates and the growth of the chicks is slower than that of broods of after-second-year hens, we could detect no difference in survival of the chicks. Yearly variation in the sex ratio of fledged young was probably the result of selection for or against larger female chicks during different environmental conditions. Broodmates associate with each other throughout the summer, and there are differences in habitat preferences between young (1-5 days old) and older (> 5 days old) broods. Older broods prefer more open, mature forest stands with fewer trees per hectare.

Book chapter↗
USGS1989

The shiny cowbird Molothrus bonariensis in the West Indian region--Biogeographical and ecological implications

The shiny cowbird (Molthrus bonariensis), an avian brood parasite, is endemic to South America, Trinidad, and Tobago, but during the last 100 years the species has spread through the West Indies. Successful colonization by the shiny cowbird depends on the availablitiy of suitable habitats and host species. As forest fragmentation increases in the West Indies, new hosts, particularly forest species, will be parasitied. Forest fragmentation creates small patches of forests surrounded by open habitat and increases the portion of forest habitat available to cowbirds.

Book chapter↗
USGS1995

Ecological and toxicological aspects of the partial meltdown of the Chernobyl nuclear power plant reactor

the partial meltdown of the 1000-MW reactor at Chernobyl, Ukraine, on April 26, 1986, released large amounts of radiocesium and other radionuclides into the environment, causing widespread radioactive contamination of Europe and the former Soviet Union. 1-7 At least 3,000,000 trillion becquerels (TBq) were released from the fuel during the accident (Table 24.1), dwarfing, by orders of magnitude, radiation released from other highly publicized reactor accidents at Windscale (U.K.) and three-Mile Island (U.S.) 3,8 The Chernobyl accident happened while a test was being conducted during a normal scheduled shutdown and is attributed mainly to human error. 3

Book chapter↗
USGS1995

The ecology of cormorants: some research needs and recommendations

Concerns about Double-crested Cormorants (Phalacrocorax auritus) have arisen because of their rapid population increase across North America and their economic impact on several aquaculture and commercial fish industries. In spite of the concern for cormorants, little published research is available that addresses either basic population biology questions or management issues. Based on a literature review, I recommend that research be conducted in four areas. First, a large-scale banding and marking program should be initiated so that population models can be used to estimate age- and sex-specific survival and fecundity (as has been done for the Shag [P. aristotelis] in Europe). By marking individual birds, survival and movement rates can be estimated between nesting colonies, which will provide information about potential source versus sink colonies. Second, studies of movements during migration and winter are required. Presently, no data are available on habitat use during migration or on the length-of-stay by individual birds. This has important implications to how cormorants interact with other fish and wildlife species over a broad range. Studies of movements during winter with radio-marked birds should indicate whether the 'problem birds' at aquaculture sites are merely a few specialists. Third, limiting factors, such as contaminants and disease, should receive further investigation, especially in light of recent concerns over the outbreak of Newcastle disease. The relationship between contaminant levels and developmental abnormalities in young cormorants in certain areas of the Great Lakes in Canada and the United States remains equivocal. Fourth, further studies are needed to document the economic impacts of cormorants on Channel Catfish (Ictalurus punctatus) and other cultured fishes and to determine ways to reduce predation by fish-eating birds. Mesocosm experiments should be conducted to evaluate how different fish extraction rates affect final productivity of fish. Controlled experiments with different exclusion and scaring devices are needed. With radio-marked birds, it should be determined what the behavioral responses are to the different scaring devises. Also, providing alternative wetland feeding sites in regions of fish farm depredation might alleviate some of the pressure on farmers. Studies with radio-marked birds could evaluate effects of manipulation of 'natural' wetlands on use by birds during the winter period. Finally, any research directed at the Double-crested Cormorant should also evaluate its interactions with other fisheating waterbirds.

Book chapter↗