WERC Highlights -- August 2001

Potential Effects of Proposed Power Plant on Mojave Desert Natural Resources: An upcoming story in the Los Angeles Times will explore the potential effects of the proposed Ocotillo power plant on nearby Joshua Tree National Park. USGS scientists at the Western Ecological Research Center were interviewed about the role of nitrogen in enhancing growth of nonnative plant species and the related potential increase in landscape flammability (research botanist Matt Brooks), and about the effects of annual plant community changes on the desert tortoise (research wildlife biologist Kristin Berry). (Matt Brooks, Las Vegas, NV, 702-914-2206 x225; Kristin Berry, Riverside, CA, 909-697-5361)

Tortoise Sidebar: Research wildlife biologist Kristin Berry of the USGS Western Ecological Research Center was interviewed about the status and trends in federally threatened desert tortoise populations in the Mojave Desert for a sidebar to accompany a story in the San Diego Union Tribune on Bureau of Land Management management plans that are in process. The population declines that contributed to federal listing in 1990 were discussed, as well as new declines between 1991 and 2001 in the eastern Mojave Desert and northern Colorado Desert. Some of the more recent contributors to population declines include shell disease, upper respiratory tract disease, poor nutrition, toxicosis, and predation by domestic dogs. (Kristin Berry, Riverside, CA 909-697-5361)

Weeding Together in the Southwest: USGS will co-host a special joint workshop with the California Exotic Pest Plant Council October 5, 2001, at the CalEPPC tenth anniversary symposium in San Diego. Land managers and scientists from federal, state, university, and nongovernmental organizations will participate in the workshop titled “The Ecology of Management of Invasive Plants in Southwestern North America.” With a focus on desert-related issues in the Chihuahuan, Great Basin, Mojave, and Sonoran deserts, the workshop is expected to foster communication between scientists who are studying invasive species and those studying physical processes that potentially control plant invasions. Interdisciplinary weed research is particularly important in the desert southwest, where harsh environmental conditions promote strong interactions between physical and biological processes that ultimately affect habitat invisibility and species invasiveness. USGS scientists will also participate in other sessions at the conference, which ends October 7. (Matt Brooks, Las Vegas, NV, 702-914-2206 x225)

Planning Pathways for Wildlife: The second in a series of workshops to develop preservation priorities in southern California based on biological and economic factors will be hosted by San Diego State University Field Station Programs, South Coast Wildlands Project, U.S. Geological Survey and co-sponsors September 14 at the Santa Margarita Ecological Reserve. Robert N. Fisher, a zoologist at the USGS Western Ecological Research Center will participate in the workshop, which will focus on the only remaining natural corridor between the coastal Santa Ana Mountains and the more extensive inland ranges. (Robert N. Fisher, San Diego, CA, 858-637-6882)

How Do Streams and Rivers Respond to Surges of Sediment? Writing in the August 2001 issue of the journal Water Resources Research, Mary Ann Madej, a research geologist at the USGS Western Ecological Research Center, reports on changes that steep mountain river channels undergo following disturbances such as wildfires, landslides, volcanic eruptions, mining and removal of dams. These disturbances can flush into streams large additions of sand and gravel as sediment pulses. Sediment pulses are of concern to land managers because they influence: the availability of aquatic habitat for salmon; sediment delivery to downstream reaches, water supplies and reservoirs; and the stability of infrastructure features such as bridge crossings and buried pipelines. Predicting how channels will react to these pulses is important in stream restoration work. Madej found that after sediment pulses occurred, the river channels were commonly shallower, less complex and rough, and had irregularly spaced gravel bars, pools and riffles. Over time the structure and organization of the river channel redeveloped, with a return ultimately to more diverse habitats. (Mary Ann Madej, Arcata, CA, 707-825-5148)

Contraceptive Vaccine for Wildlife: Judd Howell, a research manager at the USGS Western Ecological Research Center will attend the 5th International Symposium on Wildlife Fertility Control as a coauthor of the paper on the use of porcine zona pellucida vaccine as a contraceptive agent in free-ranging tule elk in Point Reyes National Seashore. Porcine zona pellucida vaccine, called PZP, is a vaccine made from pig ovaries that causes an animal's egg to become immune to sperm, thus preventing pregnancy. This paper has wide application to management of over-abundant wildlife populations around the world, such as white-tailed deer in the eastern United States or elephants in Africa. Howell has worked extensively with the University of California, Davis, in a team effort to understand the effectiveness of immuno contraception in wild populations of tule elk in California. Tule elk were reintroduced to a peninsula at Point Reyes National Seashore, but after 20 years the population was growing at a rate that potentially threatened other biological resources in the park, including the Myrtle's silverspot butterfly, a federally endangered species. The conference is being held in Kruger National Park, Republic of South Africa, August 20-23, 2001. In addition, Howell's article "Population Dynamics of Tule Elk at Point Reyes National Seashore, California" was recently accepted for publication in the Journal of Wildlife Management. (Judd Howell, Sacramento, CA, 916-379-3745)

Ducks That Are Taking a Dive: John Takekawa, a research wildlife biologist at the USGS Western Ecological Research Center was interviewed by the San Francisco Chronicle for a story about the decline of scaup and scoter ducks. During the last 20 years, breeding scaup have declined at a rate of 150,000 per year, and many sea duck populations have also decreased. The Chronicle is reporting on changes in the boreal forest regions where these diving ducks breed and on their wintering populations. Takekawa and colleagues are conducting ongoing research in coastal ecosystems including foraging ecology and contaminants in diving ducks of the San Francisco Bay estuary. They have new information on distribution, foraging, and contaminant levels of diving ducks and their winter prey. A second story on declining scaup and scoters will be published in the International Wildlife magazine in spring 2002 (John Takekawa, Vallejo, CA, 707-562-2000)

Camera Rolls on New Sea Otter Study: A videographer from Oregon Public Broadcasting's Oregon Field Guide, recorded a field day of biologists capturing Washington sea otters to collect samples. The samples will be analyzed to assess contaminant loads in new collaborative research by USGS, U.S. Fish and Wildlife Service, Olympic Coast National Marine Sanctuary, and Washington Department of Fish and Wildlife, with funding from USFWS. Ron Jameson, a research wildlife biologist at the Western Ecological Research Center, and the USGS lead scientist in this study, was interviewed onboard the research vessel and will have a second interview in September. In addition to documenting the new otter project, the story will cover translocations of sea otters to Oregon and Washington, and collaborative work by Jameson with the Seattle Aquarium and other researchers in Oregon on prehistoric populations of sea otters in both states. A sea otter story of about 30 minutes will be aired in late winter or early spring 2002. (Ron Jameson, Corvallis, OR, 541-754-4388)

Urban Ravens: William I. Boarman, a research wildlife biologist at the USGS Western Ecological Research Center was interviewed for a story in Bay Nature Magazine, a new quarterly covering the San Francisco Bay area. The article, scheduled for the upcoming winter issue, is about the increase in raven populations in urban areas, and Boarman provided information about raven genetics and population dynamics. (William I. Boarman, San Diego, CA, 858-637-6880)

Safe Pathways for Wildlife: Natural corridors that provide animals safe passage from one familiar habitat to another, are vital to the survival of dozens of species of wildlife across California. A team of biologists that has identified more than 300 such natural corridors in California will focus on the top ten in a workshop in Los Angeles, August 17. Robert Fisher, a USGS zoologist at the Western Ecological Research Center is one of the biologists participating in the workshop to develop a protocol for planning, design, and implementation for preserving or restoring the top ten-ranked wildlife corridors. It is their hope that the methodology developed as a result of this meeting will be used for other wildlife corridors throughout California. (Robert Fisher, San Diego, CA, 858-637-6882)

USGS Scientist Gives Testimony at DOI Hearings on Livestock Grazing: Kristin Berry, a USGS research wildlife biologist at the Western Ecological Research Center was one of three desert tortoise experts who testified at DOI hearings on livestock grazing changes, held in Barstow, Calif., between July 24 and August 7. The hearings were held in response to an appeal by cattle growers to a BLM decision to aid the tortoise, which is federally listed as threatened in the Mojave Desert, by limiting spring and fall grazing on portions of their allotments in the Mojave and Colorado Berry’s testimony covered the status of the desert tortoise in the Mojave and Colorado deserts of California, based on personal observations and numerous sources of data including research on the demography of desert tortoises from long-term study plots established between 1971 and 1980; and research on factors contributing to population declines (e.g., anthropogenic impacts and health and disease). She reported that California populations were declining at abnormally high rates and the reasons for the declines were numerous, often complex and interrelated. Deterioration of the ecosystem (and desert tortoise habitat) was an important factor in declines of tortoise populations. Livestock grazing is one of several impacts to tortoise populations and habitat. Cattle trample tortoises and their burrows, consume the same native plants that tortoises require, reduce cover of shrubs required for protection from predators and temperature extremes, and promote the growth of less nutritious nonnative plants A ruling is expected in about two weeks. The San Bernardino Sun, Barstow Desert Dispatch, and Victorville Daily Press reported on the hearings. (Kristin Berry, Riverside, CA, 909-697-5361)

Parasites Up Close: BBC Radio 4 will broadcast a two-part series on parasites Monday, August 13 and Monday, August 20 at 9:00 p.m. and on the Web at the following address at the time of transmission: http://www.bbc.co.uk/nature/programmes/radio/parasite/. The program will include a recent interview of USGS marine biologist Kevin Lafferty, Western Ecological Research Center. Lafferty is conducting research to develop monitoring tools that use parasites to evaluate the health of salt marshes, and he is testing parasites as biological control agents for the introduced European green crab. (Kevin Lafferty, Santa Barbara, CA, 805-893-8778)

Ranger Rick Meets Aleutian Sea Otters: Ranger Rick and friends will explore Aleutian kelp forests and learn about the sea otter’s role in maintaining balance in kelp ecosystems, in a two-part story to run in the Ranger Rick magazine this November and December. Jim Estes, a USGS research ecologist at the Western Ecological Research Center was interviewed about Alaska’s declining sea otter population in the Aleutian Islands. (Gloria Maender, Tucson, AZ, 520-670-5596)

National Geographic to Explore Aleutian Refuge: While in the Aleutians to study kelp forest ecosystems this month, Jim Estes, a USGS research ecologist at the Western Ecological Research Center, will be interviewed by National Geographic magazine for a feature story about the Alaska Maritime National Wildlife Refuge. The story, scheduled to run in October 2002, will touch on issues impacting the marine environment along Alaska's coast, including fisheries, contaminants, and endangered species. (Gloria Maender, Tucson, AZ 520-670-5596)

Point Sources of Pollution: Research wildlife biologist Kristin Berry of the USGS Western Ecological Research Center was interviewed about runoff from roads for a story in Audubon magazine for summer 2002. Berry, working with USGS geologists, is studying the effects of roads on desert tortoises and their ecosystems. Roads depress tortoise populations adjacent to roads, and the extent of the depression varies according to road type, road age, and traffic volume. She is looking at potential toxicants, sampling soils, sediments, and tortoise forage plants at varying distances from the road edge. Recent necropsies of ill tortoises at two of the study sites showed elevated levels of several potential toxicants in the livers. (Kristin Berry, Riverside, CA, 909-697-5361)

Ages of Big Trees Are Still in the News: The Los Angeles Times interviewed USGS scientist Nate Stephenson about the ages of the largest giant sequoias for an upcoming article. Stephenson noted that the largest sequoias are not necessarily the oldest, and generally owe their enormous size to rapid growth rather than great age. The General Sherman tree, the world's largest tree, is now estimated to be only about 2,150 years old, the General Grant tree is about 1,650, and the Grizzly Giant is about 1,800. Tree rings in cut sequoia stumps show that sequoias much smaller than these have reached ages of more than 3,200 years. (Nate Stephenson, Three Rivers, CA, 559-565-3176)