Publications

No abstract available.

Although the Caribbean region is considered a biodiversity hotspot and a priority for ecological conservation efforts, little information exists on population trends of West Indian landbirds. We combined avian survey data collected from three studies spanning a 16-year period on a small island with a minimal human presence in the British Virgin Islands. Although abundances varied among...

Despite significant research demonstrating effects of estrogens such as 17α - ethinylestradiol (EE2) on fish, the underlying mechanisms regulating population failure are unknown. Projected water shortages could leave waterways increasingly dominated by wastewater effluent and understanding mechanisms is necessary for conservation and management. Here we identify mechanisms of population...

Statistical models using partial differential equations (PDEs) to describe dynamically evolving natural systems are appearing in the scientific literature with some regularity in recent years. Often such studies seek to characterize the dynamics of temporal or spatio-temporal phenomena such as invasive species, consumer-resource interactions, community evolution, and resource selection

We assessed the migratory pathways, migration chronology, and breeding ground affiliation of Canada Geese (Branta canadensis interior) that winter in and adjacent to the Santee National Wildlife Refuge in Summerton, South Carolina, United States. Satellite transmitters were fitted to eight Canada Geese at Santee National Wildlife Refuge during the winter of 2009–2010. Canada Geese...

The scaling of physical, biological, ecological and social phenomena is a major focus of efforts to develop simple representations of complex systems. Much of the attention has been on discovering universal scaling laws that emerge from simple physical and geometric processes. However, there are regular patterns of departures both from those scaling laws and from continuous distributions...

We investigated nesting success of grassland birds on dry prairie and oak barrens patches embedded within a forested matrix on Fort McCoy Military Installation. We monitored 280 nests of 9 grassland-bird species from mid-May to late July 2000–2002. Pooecetes gramineus (Vesper Sparrow) andAmmodramus savannarum (Grasshopper Sparrow) were the most abundant nesting species. Vesper Sparrow...

We evaluated the influence of sex and reproductive condition on seasonal distribution and movement patterns of Lake Sturgeon Acipenser fulvescens in Namakan Reservoir, Minnesota–Ontario. Blood samples were collected from 133 Lake Sturgeon prior to spawning and plasma concentrations of testosterone and estradiol-17ß were analyzed using radioimmunoassay. Steroid concentrations were used to...

Proper classification of sites is critical for the use of biological indices that can distinguish between natural and human-induced variation in biological response. The macrophyte-based index of biotic integrity was developed to assess the condition of Minnesota lakes in relation to anthropogenic stressors, but macrophyte community composition varies naturally across the state. The goal...

Aquatic habitat in littoral environments can be affected by residential development of shoreline areas. We evaluated the relationship between macrophyte richness metrics and shoreline development to quantify indicator response at 2 spatial scales for Minnesota lakes. First, the response of total, submersed, and sensitive species to shoreline development was evaluated within lakes to...

Partitioning total variability into its component temporal and spatial sources is a powerful way to better understand time series and elucidate trends. The data available for such analyses of fish and other populations are usually nonnegative integer counts of the number of organisms, often dominated by many low values with few observations of relatively high abundance. These...

Predation from aquatic and terrestrial predators arc important factors structuring the size and depth distribution of aquatic prey. We conducted mesocosm and tethering experiments on Little Mulberry Creek in northwest Arkansas during low flows to examine the effects of predators on fish and crayfish survival in intermittent streams Using shallow artificial pools (10 cm deep) and predator