WERC Highlights -- August 2000

USGS Fire and Invasive Species Presentations Kick Off Symposium: Four USGS fire ecologists are invited speakers for the lead session at the California Exotic Pest Plant Council's Symposium 2000, Exotic Plants in the Landscape: Processes and Patterns, in Concord, California, October 6-8. Jon Keeley will explain how exotic plants can change natural fire regimes. Matt Brooks and coauthor Carla D'Antonio from the University of California, Berkeley, will address how fire can promote exotic plant invasions. Steve Knick will discuss the ecological effects that occur in ecosystems where exotic plants have altered natural fire regimes. Dave Pyke will speak on the use of fire to control exotic plants in wildlands and croplands. (Gloria Maender, Tucson, AZ, 520-670-5596)

New Website Details Science Support for Habitat Conservation Planning: Habitat conservation plans (HCPs), particularly the growing number of plans that cover large geographic areas and multiple species and habitats, address a complex array of ecological issues. The primary areas of scientific support for HCPs are ecological field data, reserve design, impact analysis, ecological monitoring, and planning and decision support. Scientists at the USGS Western Ecological Research Center (WERC) are making important contributions to the scientific foundations upon which HCPs are developed and analyzed. This new website describes each of the areas of support and presents current studies that are being conducted by WERC scientists. The HCP website home page URL is: http://www.werc.usgs.gov/hcp/. (Gloria Maender, Tucson, AZ, 520-670-5596)

Wildfire Research in California Coastal Shrublands in International News: USGS research ecologist Jon Keeley was interviewed for a story in the German newspaper Die Tageszeitung regarding his study on the role of fire suppression in coastal shrublands of southern and central California published in 1999 in the journal Science. In this study, Keeley and colleagues found that catastrophic property loss from shrubland wildfires is due to urban sprawl, which puts more people at risk, and is not due to unnatural fuel accumulation from fire suppression. Keeley was also interviewed for an article in the journal Science, speaking about methods for reducing fire hazard in forests. Keeley referred to the effective use of controlled burning without mechanical thinning in Sequoia National Park over two decades. (Jon Keeley, Three Rivers, CA, 559-565-3170)

Disease and Tortoise Declines: Research wildlife biologist Kristin Berry was interviewed for upcoming stories in the San Bernardino Sun and Sacramento Bee and discussed declines in desert tortoise populations in California, prospects for recovery of the state’s reptile, and reasons for high mortality rates. Shell disease may be a contributor to recent catastrophic losses in the eastern part of the state where Berry has studied a tortoise population near Goffs since 1980. Numbers have plummeted from 296 individuals in 1980 to 30 individuals this spring at the Goffs study site. The population losses at Goffs follow similar declines recorded at Berry's study sites in the Ward and Chemehuevi valleys and the Chuckwalla region in eastern California in the last decade. (Kristin Berry, Riverside, CA, 909-697-5361)

In a USGS Study, Contaminant Levels in Two Shore-Nesting Species Were Not Sufficiently Elevated to Cause Major Concern: Habitat loss and human-related disturbance led to federal listing of two southern California birds, the California least tern (Sterna antillarum browni) as endangered and the Pacific Coast population of western snowy plover (Charadrius alexandrinus nivosus) as threatened. Environmental contaminants such as organochlorine pesticides, PCBs, mercury, and selenium may adversely affect reproduction in birds. Because elevated levels of such contaminants could further stress the growth and stability of populations of these listed species, USGS wildlife biologists Roger Hothem and Abby Powell tested failed eggs for contaminants. Their results were recently published in the Bulletin of Environmental Contamination and Toxicology: "Contaminants in eggs of western snowy plovers and California least terns: Is there a link to population decline?" (Roger Hothem, Davis, CA, 530-752-4605)

Rare Abalone, Parasites in the News: USGS marine biologist Kevin Lafferty was recently interviewed for stories in the Los Angeles Times and the Santa Barbara News Press about efforts to restore the rare white abalone, a deep-water, marine snail so highly prized for its tender white meat that an intense commercial and recreational fishery in the 1970s virtually wiped out the species. Lafferty and colleagues have captured 9 adults and are developing the husbandry technology to try to sustain the stock through captive breeding. Lafferty spoke on another subject on which he is expert -- parasites -- as a recent guest on a 30-minute talkshow, "Intelligent Talk," on the Los Angeles NPR station KPCC. At Carpinteria saltmarsh, Lafferty discovered that a fluke (Euhaplorchis californiensis) travels through three host species and plays an important role in maintaining a natural balance in the marsh. He is currently studying whether a barnacle (Sacculina carcini), which castrates the European green crab can be used as a safe biological control for green crabs that have invaded California. Lafferty’s work on these parasites is also featured in an article on parasites in the August issue of Discover magazine. (Kevin Lafferty, Santa Barbara, CA, 805-893-8778)

Fire Interview Turned to Invasives: In a recent Philadelphia Inquirer interview regarding how wildfires in the West may effect wildlife, USGS research ecologist Cecil Schwalbe explained the role of invasive grasses in wildfires in the Sonoran and Mojave deserts. Schwalbe and colleagues determined that more than 20 percent of a sample population of saguaros died within five years following a 1994 fire in Saguaro National Park. Eleven percent of tortoises were killed outright, a catastrophic loss for this long-lived species with an expected 2 percent annual mortality. Nonnative grasses that have invaded these deserts provide more fuel to fires, allowing them to spread over larger areas. (Cecil Schwalbe, Tucson, AZ 520-621-5508)

Website Highlights Invasive Species Studies: The USGS Western Ecological Research Center has recently developed a new website for easy access to information about research that center scientists are conducting on invasive species. From the WERC home page (http://www.werc.usgs.gov), visitors can click on a photo icon that opens the invasive species website. At the website's opening page an overview of the center’s invasive species program is available with a downloadable fact sheet in PDF format. Links for several of the projects listed lead to their own web pages, where more detailed information can be found about particular studies, including downloadable project fact sheets. (Gloria Maender, Tucson, AZ, 520-670-5596)

Are Tortoises Affected by Human Migration? USGS research manager and scientist Jeff Lovich was interviewed for an upcoming story in the Desert Sun (Palm Springs) regarding the impacts of human immigration on the Chuckwalla Bench in the Colorado Desert of southern California. A new influx of illegal immigrants across once remote desert areas is impacting tortoise habitat on the Chuckwalla Bench. The highest desert tortoise densities ever estimated in California were recorded on the bench in the 1980s: over 500 tortoises per square mile. Since then, tortoise populations appear to have declined dramatically in some areas, and the tortoise is federally protected in most of the Colorado and Mojave deserts, where habitat destruction and fragmentation, fire, overgrazing, widespread use of off-highway vehicles, and other human activities have altered large areas of desert. (Jeff Lovich, Sacramento, CA, 916-278-3210)