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Technical Announcement:
From Ducks on Doppler to Climate Change: USGS at The Wildlife Society

Released: 9/23/2009 4:34:39 PM

Contact Information:
U.S. Department of the Interior, U.S. Geological Survey
Office of Communication
119 National Center
Reston, VA 20192
Catherine Puckett 1-click interview
Phone: 352-264-3532

Keeping up with plants: the challenge for Arctic geese: A large-scale redistribution of geese seems to be occurring in boreal and tundra ecosystems, perhaps because of the changing balance and distribution of the plants they eat. In Alaska, geese are breeding earlier in the year, but the advance in the breeding time of some geese species may not be keeping pace with the ever-earlier arrival of spring for plants. USGS researchers found that in exceptionally warm years in the Arctic, food plants preferred by geese are of lower nutritional quality. In addition, a changing climate may be altering the abundance of small mammals, the favored prey of the Arctic fox, and thus cause greater predation by foxes on geese. Collectively, these changes suggest that northern habitats for geese are changing in substantive ways that will reshape their fitness and future distribution. For more information, contact Joel Schmutz at jschmutz@usgs.gov or 907-786-7186.

Ducks fatten up with improved winter habitat: With few exceptions, dabbling ducks that winter in California’s Central Valley are fatter and heavier today than before the Central Valley Joint Venture habitat program effort began in 1988, according to a multi-partner study.  The additional stored fat translates into increased body reserves for wintering ducks, which may ultimately increase survival and population numbers.  The improvement in the condition of ducks is consistent with increased availability of seeds in most flooded habitats throughout the Central Valley, and especially in the Sacramento Valley. Contact Joe Fleskes at joe_fleskes@usgs.gov or 707-678-0682 x628.

Life and death at the marsh -- tracking survival of an endangered rail: Winter may be the most perilous season for the California clapper rail, according to a study by USGS and University of California, Davis, scientists. This rail is a federally and state-listed endangered species restricted primarily to San Francisco Bay, Suisun Bay, and wetlands near the mouth of San Francisco Bay. Scientists found that survival rates were lowest for the winter season (only about half survived), highest for post-breeding season (more than 3/4ths survived) and slightly less for the breeding season (about 3/4ths survived). The combined annual survival rate, however, was only one-third of the population. Low winter survival may be caused by many factors, including high winter tides (which reduce high-tide refuges), exposure from winter storms or changes in predator behavior and abundance. People may be contributing to the low survival by setting out feeding stations for feral cats. Contact Cory Overton (coverton@usgs.gov, 707-678-0682 x683), Mike Casazza (mike_casazza@usgs.gov, 707-678-0682 x629), or John Takekawa (john_takekawa@usgs.gov, 707-562-2000).

Black rail, a “barometer” of tidal marsh condition of San Francisco Bay? Though restoration seeks to reverse the loss of roughly 80 percent of tidal marshes in the San Francisco Bay Estuary, species dependent on tidal marshes, including the California black rail, still face other threats, such as from methymercury. USGS research found that the marsh foodweb consisted of three basic “food chain” levels and that methylmercury increased with each level. Though mercury toxicity thresholds for birds can vary by species, when the researchers compared their results from black rail feather and blood sampling to established risk categories for the common loon, their results indicated that many black rails in San Francisco Bay may be at risk of adverse effects from methylmercury, especially if they are more sensitive to it than loons. California black rails may be good indicators of tidal marsh condition, and methylmercury contamination may contribute to the cumulative effects of other threats such as sea-level rise, fragmentation, other contaminants, disease, and disturbance. Contact Isa Woo at iwoo@usgs.gov or 707-562-2001.

Ducks on Doppler – Weather radar detects waterfowl use of restored habitat: The national network of Doppler weather surveillance radars routinely detects a variety of bird movements and holds enormous potential for rapidly and remotely assessing bird distributions within broad geographic areas across the United States. University of Delaware and USGS scientists used archived radar data from two radars in California’s Central Valley to assess the change in wintering waterfowl use of lands enrolled in the U.S. Department of Agriculture’s Wetland Reserve Program before and after restoration. At nearly two-thirds of the restored sites, they detected significant increases in bird movements, indicating daytime waterfowl density at these sites greatly increased after restoration. Contact Joe Fleskes at joe_fleskes@usgs.gov or 707-678-0682 x628.

Black-necked stilt chicks “test” Salton Sea experimental ponds:  The Salton Sea has been described as a crown jewel of avian diversity in California, yet it faces an uncertain future due to impending water reductions. USGS scientists are examining the ecological risks and benefits of a novel restoration concept using a mixture of saline Salton Sea water and agricultural run-off at an experimental wetland complex on the Salton Sea. A 3-year study of radio-marked black-necked stilt chicks indicated lower survival and remaining at the site for chicks hatched at the experimental complex compared to nearby fresh-water wetland sites. Selenium exposure, however, had no discernible effect on chick survival. Contact Mark Ricca (mark_ricca@usgs.gov, 530-752-2505) or Keith Miles (keith_miles@usgs.gov, 530-752-5365).

Going, going, gone? Estuarine islands, wading birds, and climate change: In the mid-Atlantic region, small estuarine islands are already losing ground because of climate change, according to USGS researchers. The researchers demonstrate, for example, that islands at the Forsythe National Wildlife Refuge in New Jersey and in state-owned lands in Virginia, are suffering losses of land at a more rapid rate than local sea-level rise. These islands could be inundated by 2100. In addition, researchers said that an average island loss rate of 21 percent was accompanied by population reductions of more than 50 percent of nearly all of the wading bird species they examined. Similar losses have been noted in coastal North Carolina, Maryland, New Jersey, and New York. Management will be needed to prevent the continued decrease of nesting populations of many waterbirds. Contact Michael Erwin, merwin@usgs.gov or 434-924-3207.

Habitats suitable as home for rare giant gartersnakes: USGS scientists are uncovering habitats suitable as “homes” for the giant gartersnake, a rare, threatened species native to California’s Central Valley. Their study indicated that these snakes most prefer low-elevation sites near wetlands, canals, and rice-growing fields. In the Sacramento Valley, these sites are restricted to the central and southern portions of the valley. Based on these findings, resource managers can more accurately assess the current distribution and abundance of the snake, as well as know what habitats are important in maintaining these rare snakes. Contact Brian Halstead at bhalstead@usgs.gov or 707-678-0682 x627.

Getting to the other side of the road: predicting road risk for species in southern California’s coastal sage scrub habitats: To assess the effects of habitat fragmentation on southern California’s native species, researchers found that dirt roads generally did not hinder the movement of small mammals and reptiles. In contrast, a primary highway was an obvious barrier. Small-mammal movements over secondary paved roads differed among species. Overall, species that preferred open habitats were more likely to venture out onto roads where they were susceptible to increased mortality from cars. By understanding what species are most at risk from the presence of roads within their habitat, better management decisions can be made. Contact Cheryl Brehme at cbrehme@usgs.gov or 619-225-6427.

The Wildlife Society’s 16th Annual Conference is the week of Sept. 21st in Monterey, Calif. For more information go to http://joomla.wildlife.org/monterey09/

USGS provides science for a changing world. For more information, visit www.usgs.gov.

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