WERC Highlights -- March 2004

Fire and Wildland/Urban Interface: On March 28, USGS scientist Jon Keeley of the Western Ecological Research Center will be the featured speaker on wildland/urban interface issues involving fire and grazing at the annual meeting of the Regional Parks Association at the Trudeau Training Center in Oakland, California. Keeley will speak on "Fire and the Wildland-Urban Interface: Lessons from the 2003 Fire Season." For more information: http://www.regionalparksassociation.org/about_rpa.htm. (Jon Keeley, Three Rivers, CA, 559-565-3170, jon_keeley@usgs.gov)

Using Fire to Control Invasive Plants Workshop: USGS is co-hosting a two-day workshop with the Center for Invasive Plant Management, University of California, Davis, and the California Invasive Plant Council to evaluate the current state of knowledge on the use of prescribed fire to manage invasive plants. The workshop will address the risks and challenges of controlling invasive plants using prescribed burning, using prescribed burning in an integrated approach, impacts on plant communities, impacts on wildlife and insect populations, soil alterations, and information gaps, and will be held on March 30-31, 2004 at the USGS Western Ecological Research Center office in Henderson, Nevada. The products of this workshop will include published recommendations on using fire to manage invasive plants. (Matt Brooks, Henderson, NV, 702-564-4615, matt_brooks@usgs.gov).

Killer Whales: USGS scientist Jim Estes of the Western Ecological Research Center was quoted in the April issue of Discover magazine about a link between the rapid depletion of at least a half million great whales in the North Pacific Ocean by intensive whaling over 50 years ago to the sequential declines in recent decades of harbor and northern fur seals, Steller sea lions, and sea otters, consumed by mammal-eating, transient killer whales deprived of larger prey. (Jim Estes, Santa Cruz, CA, 831-459-2820, jim_estes@usgs.gov)

Mediterranean-type Ecosystems Workshop: USGS scientist Jon Keeley of the Western Ecological Research Center will participate in a small invitational workshop whose purpose is to design an intercontinental program on conservation and management of the five regions of the world that have Mediterranean-type ecosystems (MTEs, or the “Med-5”), focusing especially on their interdependence with human settlements and on protected areas. The workshop, to be held on March 22-24, 2004, is hosted by Santa Monica Mountains Conservancy (Malibu, California) and organized by California Institute of Public Affairs in cooperation with the IUCN - The World Conservation Union. (Jon Keeley, Three Rivers, CA, 559-565-3170, jon_keeley@usgs.gov)

Carnivore Lectures: On March 25, 2004, USGS scientist Jim Estes of the Western Ecological Research Center will give the 2003-2004 Errington lecture at Iowa State University in Ames, Iowa. Paul L. Errington, who died in 1962, was a pioneer in animal ecology. Estes’ Errington lecture will be on “Large carnivores and nature's balance.” He will also present a technical talk there on “The historical ecology of kelp forest ecosystems” on March 26. For more information: http://www.nrem.iastate.edu/errington/current_lecture.htm. (Jim Estes, Santa Cruz, CA, 831-459-2820, jim_estes@usgs.gov)

Ruby Lake Canvasbacks: Two recent studies by USGS scientist John Takekawa of the Western Ecological Research Center and colleagues investigated productivity of breeding canvasbacks at Ruby Lake National Wildlife Refuge, Nevada in the high desert of the western Great Basin. They conducted nesting studies and analyzed 14 years of nesting data on canvasbacks over a 31-year period (1970-2000) to determine factors affecting breeding performance at Ruby Lake, reported in The Auk. Reproduction was tied to water level that was highly correlated with mountain snowpack up to three years earlier, emphasizing the strong effect of climatic variations on wetland birds in that arid region. In a related study published in The Condor, they analyzed recovery records of canvasbacks banded from March to November 1968-2000 at Ruby Lake. They found that a shift occurred in winter distribution of canvasbacks from southern California and the San Francisco Bay estuary in the 1970s to the Central Valley in the 1980s and 1990s, and adult and juvenile survival decreased by 24 % between the 1980s and 1990s. These shifts may correspond to effects of El Niño weather on habitat conditions in Nevada and San Francisco Bay, and to improvements in wetlands of the Central Valley. Canvasbacks that use widely distributed and variable habitats may be good indicators of the effects of changing climate and water-use practices on waterbirds in the Great Basin. Summaries of these two studies are available at: http://www.werc.usgs.gov/pubbriefs/takekawapbmar2004b.html and http://www.werc.usgs.gov/pubbriefs/takekawapbmar2004a.html. Citations: Kruse, K. L., J. R. Lovvorn, J. Y. Takekawa, and J. Mackay. 2003. Long-term productivity of canvasbacks (Aythya valisineria) in a snowpack-driven desert marsh. Auk 120:107–119. Kruse, K. L., J. R. Lovvorn, J. Y. Takekawa, and J. Mackay. 2003. Winter distribution and survival of a high-desert breeding population for canvasbacks. Condor 105:791–804. (John Takekawa, Valleja, CA, 707-562-2000, john_takekawa@usgss.gov)

Salt Ponds: USGS scientist Nicole Athearn of the Western Ecological Research Center was interviewed by Bay Nature magazine on March 4 for an upcoming 16-page pull-out section on the South Bay salt pond restoration in the San Francisco Bay estuary. The focus of the interview was to highlight USGS banding studies of western sandpipers to examine movements of migratory birds. She was also interviewed in the field for a second article, about the 10,000-acre Napa-Sonoma Marsh salt pond restoration project. (Nicole Athearn, Vallejo, CA, 707-562-2002, nathearn@usgs.gov)

Forest Symposium: USGS research geologist Mary Ann Madej of the Western Ecological Research Center is a co-presenter of two talks at the upcoming Redwood Region Forest Science Symposium, to be held in Rohnert Park, California on March 15-17, 2004. One talk will be on the effect of suspended organic sediment on salmon-feeding behavior, and the second is on designing the most cost-effective watershed restoration strategy using optimization techniques. The conference is sponsored by the University of California-Berkeley, and conference information can be found at: http://nature.berkeley.edu/forestry/redwood.html. (Mary Ann Madej, Arcata, CA, 707-825-5148, mary_ann_madej@usgs.gov)

Coast Redwoods: On March 18, 2004, USGS ecologist Will Russell of the Western Ecological Research Center will present a California Botanical Society lecture titled "Conservation and restoration of coast redwood (Sequoia sempervirens) forests" at the University of California Berkeley. Restoration has become an important concept in coast redwood forests as unharvested stands become increasingly rare. (Will Russell, Sausalito, CA, 415-331-0847, wrussell@usgs.gov).

Shrubland Fire Management: Recent catastrophic wildfires in southern California highlight the need for effective planning and management for fire-prone landscapes. A recently published study reveals that there is generally not a strong relationship between fuel age and fire probabilities in these shrublands. The authors, including USGS scientist Jon Keeley, conducted a fire frequency analysis of several hundred wildfires over a broad expanse of California shrublands. The scientists found that the probability of burning in most shrublands increased only moderately with time since the last fire; all age classes had substantial burning and the majority of burning occurred at a relatively young age. The hazard of burning in most locations increased only moderately with time since the last fire, and a marked age effect of fuels was observed only in very limited areas. Results indicate a serious need for a re-evaluation of current fire management practice on these southern California shrubland landscapes, which is based in part on fuel treatments that attempt to create age mosaics of young fuels as a potential barrier to fire spread. For more info, see: http://www.werc.usgs.gov/pubbriefs/keeleypbmar2004.html. (Jon Keeley, Three Rivers, CA, 559-565-3170, jon_keeley@usgs.gov)

Bullfrog Predation of Giant Garter Snake: The giant garter snake is a federally and state-listed threatened species found only in the Central Valley of California, and identifying sources of mortality are important in managing its recovery. In a recent study published in California Fish and Game, USGS scientists Glenn D. Wylie, Michael L. Casazza, and Michael Carpenter of the Western Ecological Research Center found that abundant, nonnative bullfrogs are significant predators of giant garter snake young of the year at Colusa National Wildlife Refuge (NWR), California. Based on stomach content of bullfrogs, they estimated the annual predation by bullfrogs to be about 22 % of the total number of young produced. The authors also calculated a 20 % tail loss from bullfrog predation for all other size classes of giant garter snakes on the refuge. A summary of this study and management implications are available online at: http://www.werc.usgs.gov/pubbriefs/wyliepbfeb2004.html. Citation: Wylie, G. D., M. L. Casazza, and M. Carpenter. 2003. Diet of bullfrogs in relation to predation on giant garter snakes at Colusa National Wildlife Refuge. California Fish and Game 89(3):139–145. (Glenn Wylie, Dixon, CA, 707-678-0682 x616, glenn_wylie@usgs.gov)

Riparian Restoration: A common goal of riparian restoration is to create habitat for bird species threatened by habitat loss, and monitoring bird communities is useful in evaluating the progress of restored sites. By examining changes in bird guild structure and abundance over time at a southern California restoration site, USGS scientists Dr. Barbara E. Kus and Peter P. Beck of the Western Ecological Research Center identified a list of 13 species, roughly one-tenth of the bird species typical of southern California woodlands, that collectively serve as an “indicator” guild for tracking habitat change. Focusing on this subset of species for monitoring efforts can save time and resources, and provides a standardized and quantitative means for using bird community development to track restoration success. The results of this research are published in a new book on California riparian systems. A summary of this study and management implications are available online at: http://www.werc.usgs.gov/pubbriefs/kuspbfeb2004a.html. Citation: Kus, B. E., and P. P. Beck. 2003. An approach for monitoring bird communities to assess development of restored riparian habitat. Pages 396–406 in P. M. Faber (ed.). California Riparian Systems: Processes and Floodplain Management, Ecology, and Restoration. Riparian Habitat Joint Venture, Sacramento, Calif. (Barbara Kus, San Diego, CA, 858-637-6881, barbara_kus@usgs.gov)

Nest Predators of Least Bell’s Vireo: Predation is the major cause of nest failure in open-nesting birds, but predation is rarely witnessed, and the identity of specific predator species is largely unknown. In a recent study published in the Journal of Field Ornithology, USGS scientists Barbara E. Kus and Bonnie L. Peterson, and Douglas H. Deutschman, an assistant professor at San Diego State University, used point counts and tracking stations to identify ten potential nest predators of the endangered least Bell’s vireo at study sites on two rivers in northern San Diego County, California. A 48 % predation rate was documented by specialized miniature video cameras trained on active vireo nests: Western scrub-jays were the major nest predator, responsible for 67 % of predation events. Other confirmed predators include Virginia opossum (17 %), gopher snake (8 %), and Argentine ants (8 %). A summary of this study and management implications are available online at: http://www.werc.usgs.gov/pubbriefs/kuspbfeb2004b.html. Citation: Peterson, B. L., B. E. Kus, and D. H. Deutschman. 2004. Determining nest predators of the Least Bell’s Vireo through point counts, tracking stations, and video photography. Journal of Field Ornithology 75(1):89–95. (Barbara Kus, San Diego, CA, 858-637-6881, barbara_kus@usgs.gov)

Suisun Marsh Waterbirds: USGS scientists Josh Ackerman and John Takekawa of the Western Ecological Research Center spoke at the Making Science Work for Suisun Marsh Workshop, on March 1-2, 2004 in Sacramento, California, sponsored by the San Francisco Bay-Delta Science Consortium and California Bay-Delta Authority. The purpose of the workshop was to ensure that research, restoration, and management decisions in the Suisun Marsh are supported by the best available science. Ackerman spoke on wintering and breeding waterfowl of Suisun Marsh and Takekawa spoke on differences in waterbird communities and abundances between managed ponds and tidal marsh. (Josh Ackerman, Davis, CA, 530-754-4148, jackerman@usgs.gov; John Takekawa, Vallejo, CA, 707-562-2000, john_takekawa@usgs.gov)