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My skillset and diverse background in ecology, conservation, and geography have allowed me to work in ecological systems all over the world.

 

Currently, my research focuses on the following subjects and ecological systems:

Photo credits: (1) western pond turtle - Adam G. Clause, (2) jaguar - James Godwin , (3) yellow-tailed woolly monkey - Kevin Schafer, (4) piping plover - Fran Baer, (5) red-cockaded woodpecker - Michelle Jusino, (6) golden-headed lion tamarin - Leonardo Oliveira, (7) tiger - Andrew Kulin.

Forecasting the effects of sea-level rise on piping plover habitat

This work is in the early stages of development. I will be working closely with my advisors (E. Robert Thieler, Nathaniel Plant, and Sarah Karpanty) at the US Geological Survey and Virginia Tech as well as collaborators form the USGS, the US Fish adn Wildlife Service, and the North Atlantic Landscape Conservation Cooperative. We will be studying the impacts of sea-level rise and changes in the frequency and intensity of coastal storms on piping plover (Charadrius melodus) habitat availability using a set of linked Bayesian networks.

Population viability and conservation in spatiotemporally dynamic landscapes

Much of what is known about the importance of habitat configuration for metapopulation persistence has come from studies of species inhabiting relatively stable or static landscapes. However, many landscapes are dynamic, reflecting situations in which both habitat patches and the connections among them are transient. In such systems, temporary windows of habitat availability and connectivity are critical for gene flow and persistence for resident species. Anthropogenic changes that disrupt the frequency or duration of these windows (e.g., droughts induced by climate change, damming of rivers) will have major impacts on species in dynamic landscapes. I will explore the impacts of anthropogenic change on dynamic landscapes and the species they support, with a specific focus on empirical systems. The first system of investigation will be the piping plover (Charadrius melodus). In collaboration with Drs. Daniel Catlin, James Fraser (Department of Fish and Wildlife Conservation, Virginia Tech) and their colleagues, I will determine past, current and optimal rates of habitat turnover in the Missouri River for this species using remote sensing, connectivity, and demographic modeling. I will also predict likely future rates of habitat turnover (given climate change and the damming of the river) and the implications for this change on piping plover populations. This information, which is of interest for both theoretical and practical applications, will be used to inform conservation management for this species and its habitat. Funding proposals for this work are currently in development.

Development of applied landscape-population tools for the conservation of endangered species

As a postdoctoral researcher, I worked with Dr. Jeffrey Walters (Department of Biological Sciences, Virginia Tech) and others on the creation of user-friendly modeling tools for use on military installations in the United States. I developed a state-and-transition model of longleaf pine (Pinus palustris) ecosystem dynamics and linked this model to an existing demographic model for red-cockaded woodpeckers (RCWs; Picoides borealis). The intention is that installation land managers will use this combined tool to evaluate the impacts of proposed landcover changes (e.g., range construction) and climate change on RCW populations, allowing for scientifically informed decision-making and landuse planning. I will continue to work with Dr. Walters on the development and application of these tools.

 

In addition, modeling platforms that can simulate the dynamics of social species are lacking, despite the fact that social behavior can be a major driver of population trends (Zeigler and Walters in review*). Such tools are particularly important for evaluating the potential impacts of threats and management actions within an adaptive management program for endangered species – especially because small, sensitive populations of endangered species make experimentation in the field impossible. I plan to continue to work with Dr. Walters to generalize the existing RCW demographic model, which is spatially explicit and incorporates social behavior in simulations, so that it can be applied to other social species. We have submitted a funding proposal for this work to the Department of Defense’s Legacy Program.

 

Finally, I have collaborated since 2004 with a group of leading experts in the field of conservation biology (e.g., Drs. Robert Lacy, Resit Akçakaya) on the development of metamodels for conservation (Lacy et al. in revision*). We define metamodels as a suite of stand-alone, disciplinary-specific models that can be linked to simulate highly complex processes in real systems. In a metamodel, the outputs of one model might act as inputs into others, and a centralized program (MetaModelManager) facilitates the passing of information between models. These tools can be used to evaluate a variety of hypotheses (e.g., the mechanisms by which threats operate on a population) - information that can be used to effectively manage endangered species. I will continue to work within this collaborative network in the conceptualization, development, and application of metamodels for conservation, which is partially funded by a National Science Foundation Research Collaboration Network grant.

Golden-headed lion tamarin conservation in a human-modified landscape

As part of my dissertation research, I created a landscape conservation plan for the endangered golden-headed lion tamarin (GHLT; Leontopithecus chrysomelas) in Bahia State, Brazil. As part of this research, I located habitat patches that could support viable populations of GHLTs and highlighted areas of potential connectivity. I plan to expand upon this research by investigating habitat and movement-related concerns for the species in collaboration with other GHLT researchers in the field (e.g., Drs. Becky Raboy, University of Toronto; Kristel De Vleeschouwer, Centre for Research and Conservation-Royal Zoological Society of Antwerp; and Leonardo Oliveira, Universidade Federal do Rio de Janeiro). Of particular interest are two questions:  (1) How does landscape connectivity compare with patterns of genetic differentiation for the species and (2) What is the future viability of the species given the loss of habitat (specifically, cabruca agroforests)? In addition, I hope to update past applied research as new information on GHLT survival, dispersal parameters, and habitat availability becomes available. This information will be critical in managing and recovering this endangered primate. The approaches used in this avenue of research could also easily be applied to other species and landscapes as opportunities arise.

Current Research

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