Hierarchical Modeling

The U.S. Geological Survey’s Eastern Ecological Science Center is home to the Northeast Amphibian Research and Monitoring Initiative (NEARMI), one of 7 ARMI regions across the United States. NEARMI works on public lands in thirteen states from Maine to Virginia, including many National Parks and National Wildlife Refuges.

Eastern Ecological Science Center biologists are studying migration and population ecology of the rufa red knot, a bird species that is dependent on horseshoe crab eggs to complete its trans-hemispheric migration. The birds' spring migration is timed with spawning of horseshoe crabs because the eggs are the perfect food for a migrating red knot.

The Waterfowl Breeding Population and Habitat Survey (WBPHS) is a primary source of waterfowl population status and trend information for management of ducks in North America. The survey has not been reviewed in several decades, and since the last review new analysis approaches and information needs have created a need to reassess the design, scope of inference, and analysis of the survey to...

We are working closely with multiple partners to provide updated information, model potential outcomes, and identify key uncertainties relevant to amphibian and reptile species proposed for listing in the northeast US. We also provide timely science to partners to assist in recovery of listed species, which may involve field research, data analysis, or decision support.

This project is an effort to create spatially and temporally explicit models for waterfowl distribution across the United States for use in avian influenza transmission risk modeling.

The Challenge: The primary dune along barrier island beaches protects leeward vegetation from tidal fluctuation, salt spray and storm surge. However, storm surges like those experienced during Hurricane Sandy can obliterate the primary dune, transporting sand inland and burying existing vegetation. The dune rebuilds naturally as recovering vegetation traps wind-blown and waterborne sand. The rate...

It is (relatively) easy to construct complex hierarchical models for analysis of the North American Breeding Bird Survey (BBS), but deciding which model best describes population change is difficult. We are developing methods for model selection for BBS and other important survey data sets, and using them to refine our estimates of population change from this important survey.

Designing and analyzing large-scale animal surveys is an important focus of our research. Although we conduct research into analysis methods for many surveys, the primary focus of this project is to conduct analyses and develop web-based summaries of data from the North American Breeding Bird Survey (BBS).

The Challenge: Research goals of this project are to develop models, statistical methods, sampling strategies and tools for inference about animal population status from survey data. Survey data are always subject to a number of observation processes that induce bias and error. In particular, inferences are based on spatial sampling – we can only ever sample a subset of locations where species...

The Challenge: For decades, capture-recapture methods have been the cornerstone of ecological statistics as applied to population biology. While capture-recapture has become the standard sampling and analytical framework for the study of population processes (Williams, Nichols & Conroy 2002) it has advanced independent of and remained unconnected to the spatial structure of the population or the...

The Challenge: Wildlife science and management are guided by data, and it is unquestionably the case that the greatest success occurs when good data are analyzed by good statistical methods.

The Challenge: Much of wildlife research consists of the description of variation in data. Some of the variation results from spatial and temporal change in populations, while some results from biologically irrelevant sampling variation induced by the process of data collection. Distinguishing relevant from irrelevant variation is the first task of statistical analysis, but the job does not end...