News from Scientists at the USGS Patuxent Wildlife Research Center
Monday, February 11, 2002
| Chytrid
Fungus Implicated in Mortality and Population Declines of Several
Amphibians
A recently discovered chytrid fungus identified as Batrachochytrium dendrobatidis has been implicated in mortality and population declines of several species of amphibians throughout the world. Identification of the fungus in the epidermis of amphibian skin has usually been associated with large-scale mortalities at specific sites. Because the origin of the fungus is under debate, we sought to determine the incidence of chytridomycosis in a geographic location where no die-offs associated with the fungus had been documented. From April-September, 2000 on rainy nights we collected 313 specimens (mostly vehicle-killed) that were usable. We used a compound microscope (40 and 100X objectives) to determine infections in tissue from fresh toe webbing and histology (haematoxylin and eosin stains) to determine infections in toe webbing and from skin excised from between hind legs. Infection rates were 16% in 38 Bufo americanus, 0% in 42 Hyla versicolor, 0% in 20 Pseudacris crucifer, 20% in 41 Rana catesbeiana, 38% in 74 R. clamitans, 36% in 14 R. palustris, 45% in 42 R. pipiens, 50% in 2 R. septentrionalis, and 15% in 40 R. sylvatica. Infected specimens came from 25 different townships throughout Maine confirming the widespread distribution of chytridiomycosis in Maine. Contact: Jerry R. Longcore 207 581-2874 Patuxent Hosts Meeting Concerning Status of Anacostia Reconstructed Wetlands On Thursday, January 31 the USGS PWRC hosted a U.S Army Corps of Engineers (COE) meeting concerning the status of the reconstructed wetlands in the Anacostia. In attendance were staff from the US Fish and Wildlife Service (Annapolis Field Office), National Park Service (National Capital Region), the District of Columbia Department of Environmental Health and the University of Maryland. For the first part of the meeting PWRC and FWS gave presentations on the results of post- reconstruction freshwater tidal marsh monitoring studies as supported by the COE and D.C. The data from these clearly defined the problems occurring at the marshes. Following these an intensive discussion was conducted concerning how best to control the decimation of the marshes by resident Canada geese browsing. It was determined to install an interim series of perimeter and interior protective fences to protect important marsh portions and new plantings. A Management Plan to control the geese was called for. It was also felt that a goose biology study should be conducted. Contact: Dick Hammerschlag 301.497.5555 |
Pattee
Attends Maryland CFWRU Annual Meeting
Dr. Oliver H. Pattee attended the Maryland Cooperative Fish and Wildlife Research Unit's annual meeting 1/25/2002 at the University of Maryland - Eastern Shore (UMES). Presentations by students included 3 wildlife projects that Dr. Pattee has been involved in. He has provided technical expertise for the Delmarva fox squirrel project at Chincoteague National Wildlife Refuge; he obtained funding from the Joint Fire Science Program for a new study on squirrels at Chincoteague; and he obtained funding from the BEST program to support a graduate student to conduct a project on the role of contaminants in species decline. He has served as a committee member on the latter 2 projects and holds an adjunct appointment as an Associate Professor in the Department of Agriculture and the Department of Natural Sciences at UMES. Dr. Pattee and cooperators(FWS and BRD) have been granted funding from the Joint Fire Science Program for a proposal titled "Prescribed fires in mid-Atlantic coastal plain forests". Dr. Pattee and Dr. Carol Bocetti will be evaluating the impact of the burning program on the endangered Delmarva fox squirrel. Contact: Dr. Oliver H.
Pattee 301.497.5741 Urban Sprawl and Warm Weather - How Do Birds React?: Dr. Joe Meyers, USGS Patuxent-Athens, was interviewed by Lee Shirra on the Athens Banner Herald concerning recent unusual bird sightings in central and north Georgia. Short term weather events do affect birds, but long term landscape changes are the reason many birds become invaders in or disappear from the local environment. Warmer winter weather seems to have given northern migration a jump start for Sandhill Cranes in Georgia, but more than likely it's just cranes searching for food slightly north of their wintering areas. Bird migrate occurs based on weather and amount of daylight. Longer days will increase the migratory urge and cause increases in stored body fats for the trip. In Athens, Georgia since the 1940s, Song Sparrows, House Finches, American Robins, and House Wrens have become invading birds that once nested only north of here. Landscapes changes, especially increases in suburban areas, are thought to be the reason for the invasion of these birds. They find habitat in suburban areas that allows them to successfully nest. Birds, however, may have increased predation from house cats in suburban areas, among other predators. It's not known how successful nesting birds are in suburban habitat, but some species, such as the House Finch, seem to be increasing at extremely high rates. While these bird populations increase, some of our forest birds may be declining because of loss of habitat and habitat fragmentation. Pileated Woodpeckers require large areas of forest to live and raise young, so this resident bird would be affected negatively by suburban sprawl. Our wood warblers, which migrate to the neotropics, would be another group of birds that may decline from loss of habitats. Conservation of habitat is the best way to assist our declining bird populations. Contact: J. Michael Meyers, PhD. 706-542-1882 |
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