Publications

We studied relationships among sediment variables (carbon content, C:N, hardness, oxygen penetration, silt-clay fraction), hydrologic variables (dissolved oxygen, salinity, temperature, transparency, water depth), sizes and biomass of common invertebrate classes, and densities of 15 common waterbird species in ponds of impounded freshwater, oligohaline, mesohaline, and unimpounded...

Differences in reaction distance to prey fish by piscivorous salmonids can alter predator–prey interactions under different visual conditions. We compared reaction distances of three piscivorous salmonids commonly found in western lakes: cutthroat trout, Oncorhynchus clarki utah, rainbow trout, O. mykiss, and the nonnative lake char, Salvelinus namaycush. Reaction distances to salmonid...

We examined home range size and habitat use of nine female northern myotis (Myotis septentrionalis) within an intensively managed forest in the central Appalachians of West Virginia. Using the 95% adaptive kernel method, we calculated a mean home range of 65 ha. Northern myotis used recent diameter-limit harvests and road corridors more than expected based on availability of these...

No abstract available.

Direct approaches for estimating the feeding rate of the opossum shrimp Mysis relicta can be hampered by variable gut residence time (evacuation rate models) and non-linear functional responses (clearance rate models). Bioenergetics modeling provides an alternative method, but the reliability of this approach needs to be evaluated using independent measures of growth and food consumption...

We examined the potential role of food limitation in constraining the recovery of sea otters Enhydra lutris in Prince William Sound, Alaska, following the 'Exxon Valdez' oil spill. The spill resulted in the removal of a large number of sea otters in 1989, and as of 1998, the portion of the population in the heavily oiled northern Knight Island region had not fully recovered. Between 1996...

The objective of this study was to determine dietary overlap between blueback herring and threadfin shad in J. Strom Thrumond Reservoir, South Carolina/Georgia. We also evaluated prey selectivity for each speices and diet differences between two size categories of blueback herring. Diet and zooplankton samples were collected every other month from April 1992 to February 1994. We examined...

We compared cavity-nesting bird communities in aspen (Populus tremuloides) woodland fragments classified on the basis of vegetation structure (tree density) and landscape context (surrounding vegetation). We found very few cavity nesters in fragments predominantly surrounded by forests. Fragments adjacent to meadows contained more species and a greater abundance of cavity nesters...

We used a supplemental-feeding experiment, the doubly labeled water technique, and a model-selection approach based upon the Akaike Information Criterion to examine effects of food availability on energy expenditure rates of Black-legged Kittiwakes (Rissa tridactyla) raising young. Energy expenditure rates of supplementally fed females (n = 14) and males (n = 16) were 34 and 20% lower...

In this paper, we briefly discuss some of the fundamental problems arising from the inherent complexity of larger-scale ecological systems. We examine the tenuous assumption of a direct correspondence between ecological data and theory, we comment on a recent report that evaluated the efficacy of fragmentation experiments, and we briefly assess its implications for ecological research...

No abstract available.

Various aspects of population structure and dynamics of Eleutherodactylus coqui in two forest reserves (Maricao and Guilarte) of the central mountain range of Puerto Rico were determined between July 1997 and June 1998. Adult density ranged from 8–25 animals/100 m2 for the wet season and 3–19 animals/100 m2 for the dry season. Abundance of froglets and juveniles was also greater in the...