Publications

The Florida torreya (  Torreya taxifolia) is a coniferous tree endemic to a 35-km stretch of bluffs and ravines along the east side of the Apalachicola River in northern Florida and southern Georgia. This formerly locally abundant tree has declined as a result of disease during the 1950s and is on the U.S. endangered species list. With no seed production in the wild, this species is headed toward

No abstract available.

We present a comprehensive survey of genetic variation across the range of the narrowly distributed endemic Yosemite toad Bufo canorus, a declining amphibian restricted to the Sierra Nevada of California. Based on 322 bp of mitochondrial cytochrome b sequence data, we found limited support for the monophyly of B. canorus and its closely related congener B. exsul to the exclusion of the widespread

We evaluate the empirical and theoretical support for the hypothesis that a large proportion of native species richness is required to maximize ecosystem stability and sustain function. This assessment is important for conservation strategies because sustenance of ecosystem functions has been used as an argument for the conservation of species. If ecosystem functions are sustained at relatively lo

Examination of blood films from wood ducks (Aix sponsa) from several northeastern states revealed Haemoproteus, Leucocytozoon, Plasmodium and a typanosome. Haemoproteus occurred in all areas sampled and birds of the year from Massachusetts demonstrated the highest incidence during the last 2 weeks in August. Leucocytozoon was most prevalent in more northern areas. P. circumflexum and a trypanos

In the 1970s about 1,650 southern sea otters (Enhydra lutris nereis) were restricted to the central California coast (Riedman and Estes, 1990), and a high volume of oil was being shipped through the region. Because of the vulnerability of sea otters to contamination from oil (Costa and Kooyman, 1982; Williams and Davis, 1995) that would likely spread wide- ly along the shore after a large spill (

Soil-food-chain-pesticide wildlife relationships were investigated to learn the concentration of pesticide residues present in soils, macro-invertebrates, vertebrates, and seeds as a result of annual applications of aldrin at recommended rates for pest control. Two central Missouri cornfields treated witb aldrin at 1 lb/acre, for 16 and 15 of the past 17 years, were selected for study during 1965

No abstract available.

Brains of juvenile gray bats, Myotis grisescens, found dead beneath maternity roosts in two Missouri caves contained lethal concentrations of dieldrin. One colony appeared to be abnormally small, and more dead bats were found a year after the juvenile bats had been collected. This is the first report to link the field mortality of bats directly to insecticide residues acquired through the food cha

The nearshore coastal areas of Belize and of Chetumal Bay, Mexico, support one of the largest populations of manatees (Trichechus manatus manatus) in the Caribbean. In order to further document the distribution, relative abundance, habitat associations, and status of this population, we conducted three aerial surveys. The flights were done in January 1994, May 1994, and January 1995. Total manatee

Aquatic hazing devices recently have been developed as a possible means of deterring waterbirds from oil spills, thereby reducing casualties. However, the effectiveness of these devices has not been examined with rigorous statistical tests. We conducted a study in the San Francisco Bay estuary to develop a design for testing the effectiveness of an aquatic hazing device on waterbirds in open water

We contrasted body condition, and age-specific reproduction and mortality between a growing population of sea otters (Enhydralutris) at Kodiak Island and a high-density near-equilibrium population at Amchitka Island, Alaska. We obtained data from marked individuals, population surveys, and collections of beach-cast carcasses. Mass:length ratios indicated that females (but not males) captured in 19