Publications

We present a hierarchical extension of the Cormack–Jolly–Seber (CJS) model for open population capture–recapture data. In addition to recaptures of marked animals, we model first captures of animals and losses on capture. The parameter set includes capture probabilities, survival rates, and birth rates. The survival rates and birth rates are treated as a random sample from a bivariate...

Bart et al. (2004) develop methods for predicting needed samples for estimation of long-term trends from Count survey data, and they apply these methods to the North American Breeding Bird Survey (BBS). They recommend adding approximately 40% more survey routes ill the BBS to allow for estimation of long-term (i.e., 20 year) trends for a collection of species. We critique several aspects...

We compared habitat and biota between paired open and forested reaches within five small streams (basin area 10?20 km2) in suburban catchments (9%?49% urban land cover) in the Piedmont of Georgia, USA. Stream reaches with open canopies were narrower than forested reaches (4.1 versus 5.0 m, respectively). There were no differences in habitat diversity (variation in velocity, depth, or bed

Knowledge of factors influencing animal distribution and abundance is essential in many areas of ecological research, management, and policy-making. Because common methods for modeling and estimating abundance (e.g., capture–recapture, distance sampling) are sometimes not practical for large areas or elusive species, indices are sometimes used as surrogate measures of abundance. We...

Roseate Tern (Sterna dougallii) nests were monitored at Falkner Island, Connecticut, USA between 1998 and 2002. A total of 586 chicks were sexed and their growth measured during the first three days. These data were used to derive growth parameters and predict survival to fledging with high confidence. In contrast to a previous study in Massachusetts, we found no sex-ratio bias at...

Survival and fecundity are fundamental to the study of evolutionary ecology, as they are two of the key variables influencing the constrained optimization process we call natural selection. Likewise, population managers require accurate estimates of these parameters; along with dispersal, they govern population dynamics (Lack 1954) and thus are essential for predicting population change...

Although seed dispersal is assumed to be a major factor determining plant community development in restored wetlands, little research exists on density and species richness of seed available through dispersal in these systems. We measured composition and seed dispersal rates at a restored tidal freshwater marsh in Washington, DC, USA by collecting seed dispersing through water and wind...

Time-lapse video photography has become a valuable tool for collecting data on avian nest activity and depredation; however, commercially available systems are expensive (>USA $4000/unit). We designed an inexpensive system to identify causes of nest failure of American Oystercatchers (Haematopus palliatus) and assessed its utility at Cumberland Island National Seashore, Georgia. We...

Previous studies have shown that variations in environmental conditions play a major role in explaining variations in plant species richness at community and landscape scales. In this study, we considered the degree to which fine-scale spatial variations in richness could be related to fine-scale variations in abiotic and biotic factors. To examine spatial variation in richness, grids of...

We developed models to predict the potential response of wintering Neotropical migrant and resident bird species to alternative management scenarios, using data from point counts of birds along with habitat variables measured or estimated from remotely sensed data in a Geographic Information System. Expected numbers of occurrences at points were calculated for 100 species of birds, under...

Surveys of surf scoters (Melanitta perspicillata) along the Atlantic coast of the United States have shown population declines in recent decades. The Chesapeake Bay has traditionally been a key wintering area for surf scoters. Past and present research has shown that bivalves constitute a major food item for seaducks in the Chesapeake Bay, with surf scoters feeding primarily on hooked...

National Wildlife Refuges must manage habitats to support a variety of species that often have conflicting needs. To make reasonable management decisions, managers must know what species are priorities for their refuges and the relative importance of the species. Unfortunately, species priorities are often set regionally, but refuges must develop local priorities that reconcile regional