Publications

Because many anurans have well-defined breeding seasons and male anurans produce loud advertisement calls, surveys of these breeding choruses are believed to provide a dependable means of monitoring population trends. The Patuxent Research Refuge initiated such a calling survey in the spring of 1997, which uses volunteers to collect anuran (frog and toad) calling survey data. The primary...

1. Stephens et al. (2005) argue for 'pluralism' in statistical analysis, combining null hypothesis testing and information-theoretic (I-T) methods. We show that I-T methods are more informative even in single variable problems and we provide an ecological example. 2. I-T methods allow inferences to be made from multiple models simultaneously. We believe multimodel inference is the future...

Studies of the impact of environmental contaminants on reproduction have typically focused on effects on fertility and subsequent reproductive failure. Contaminants may also impact reproductive output or other aspects of life history through effects on resource acquisition or allocation. We fed successfully breeding female white-footed mice (Peromyscus leucopus) diets containing...

In 1997 and 1998 we weighed nestling tree swallows (Tachycineta bicolor) and measured selected body components at two colonies: Acadia National Park on Mt. Desert Island, and at Orono, ME. We used differences in mean growth variables among individual nestlings to evaluate differences between colonies, years, and amount of total mercury (THg) in carcasses and methyl mercury (MeHg) in...

The importance of human activity and ecological features in influencing African forest elephant ranging behaviour was investigated in the Rabi-Ndogo corridor of the Gamba Complex of Protected Areas in southwest Gabon. Locations in a wide geographical area with a range of environmental variables were selected for patch-occupancy surveys using elephant dung to assess seasonal presence and...

Despite the accepted importance of the need to better understand how natal location affects movement decisions and survival of animals, robust estimates of movement and survival in relation to the natal location are lacking. Our study focuses on movement and survival related to the natal location of snail kites in Florida and shows that kites, in addition to exhibiting a high level of...

The known type specimens of Crocodilia and Testudines in the collection of the Division of Amphibians and Reptiles, National Museum of Natural History, Smithsonian Institution, published through 2006 represent 93 names of taxa. The catalog presents a list of 249 type-specimen records consisting of 39 holotypes, 52 syntypes, 3 lectotypes, 2 neotypes, 132 paratypes, and 21 paralectotypes...

Invasive plant species can have profound negative effects on natural communities by competively excluding native species. Berberis thunbergii (Japanese barberry), Frangula alnus (glossy or alder buckthorn) and Lythrum salicaria (purple loosestrife) are invasive species known to reduce native plant diversity and are thus of great concern to Acadia National Park. Pollinators visit them for...

We review wildlife/mercury literature and our own research findings that demonstrate the relevance of wildlife toxicity data in protecting human health. Methylmercury affects wildlife through reduced adult survival and reproduction, aberrant behavior, immune system effects, and teratogenic effects. Methylmercury can readily cross the blood-brain barrier, is excreted into eggs in birds...

From 1993 to 1999, we conducted banding and telemetry studies of fall migrant Soras (Porzana carolina) in the historic rail hunting and exceptional stopover habitat of the Wild Rice (Zizania aquatica) marshes of the tidal Patuxent River. Drift traps equipped with audio lures produced 3,897 Sora and 417 Virginia Rail (Rallus limicola) captures during the seven-year study. Sora captures...

We used an over-dispersed Poisson regression with fixed and random effects, fitted by Markov chain Monte Carlo methods, to model population spatial patterns of relative abundance of American woodcock (Scolopax minor) across its breeding range in the United States. We predicted North American woodcock Singing Ground Survey counts with a log-linear function of explanatory variables...

The freshwater oligochaete, Lumbriculus variegatus, is tank-cultured to provide organisms for aquatic-habitat assessments, regeneration research and as a clean source of live food for aquarium fishes. Shredded paper is the typical substrate in cultures used to rear L. variegatus for these purposes. However, the effort needed to separate large numbers from decomposing paper can be...