Population and Genetic Modeling Methods for Assessing Species Viability and Evaluating Conservation Strategies
The ability of populations to sustain themselves in the face of global change, habitat fragmentation and loss, invasive species, and other threats depends on population processes that occur over large scales. As a result, conservation efforts increasingly target larger spatial scales. Landscape-based demographic models have rarely been applied at ecoregional scales. Estimating population growth at this scale requires models to consider large-scale processes that are poorly understood. For example, dispersal between population sources and population sinks are regarded as important drivers of populations; however, we still lack complete understanding of these dynamics in regional populations. Furthermore, integration of fine scale habitat data across large spatial extents results in populations with spatial structures beyond the computational limits of many population modeling programs. Therefore, an approach that can address important processes while avoiding these constraints is needed so that populations can be effectively modeled at ecoregional scales.
Assessing Bird Species Viability at Landscape and Ecoregional Scales
We are developing approaches to extending landscape-scale demographic models to an ecoregional scale for conservation planning. Implicit in this approach is our belief that models such as those developed here are useful for conservation even when based on imprecise parameters or assumptions about processes because they synthesize current knowledge in a transparent way, can be used to quantify uncertainty, and are required to assess variability at meaningful scales. One project is focused on three priority species of breeding songbirds (wood thrushes [Hylocichla mustelina], prairie warblers [Dendroica discolor}, and worm-eating warblers [Helmitheros vermivorum]) in the Central Hardwoods Bird Conservation Region. We selected these three species because of their priority in regional conservation efforts and because they represent a variation in suitable habitats and life history strategies.
Another project we are working on is developing viability models for endangered golden-cheeked warblers on Balcones Canyonlands Preserve and at the U.S. Army Fort Hood, Texas. We are working with cooperators to collect relevant demographic data and parameterize spatially explicit demographic meta-population models.
Bat Populations and White-nose Syndrome
Northern Research Station (NRS) scientists are helping unravel the mysteries of white-nose syndrome (WNS), a fungal disease devastating bat populations in eastern North America. Bats are a vital component of many ecosystems, eating billions of insects, including forest and crop pests. Many bat species may be extirpated due to the rapid spread of cold-loving fungus (Geomyces destructans), previously unknown to science. Several bat species at risk from WNS are federally designated endangered species, including the Indiana bat (Myotis sodalis), gray bat (Myotis grisescens), and Virginia big-eared bat (Corynorhinus townsendii virginianus). Our research includes evaluating the genetic viability of Indiana bat and gray bat as this disease moves west. Using DNA microsatellites, population characteristics and structure are being evaluated towards a goal of optimizing conservation efforts for these species.
Bird Species Viability at Ecoregional Scales
We extended landscape-based population models to ecoregional scales for three species of concern in the Central Hardwoods Bird Conservation Region and compared model projections against long-term trend data from the North American Breeding Bird Survey. We used a spatially-explicit demographic model and structured the regional population into ecological subsections on the basis of habitat, landscape patterns, and demographic rates to assess species viability. Our model projections were within 2% of the Breeding Bird Survey trends over the last 40 years for each species. Wood thrush populations remained relatively stable over the simulation and worm-eating warbler abundance increased throughout most of the time period until reaching carrying capacity. In contrast, the prairie warbler population steadily declined by 0.59% annually. The combination of habitat and demographic modeling allowed us to create models that address processes driving these populations at all scales, which is critical to understanding how regional populations respond to landscape processes such as habitat loss and fragmentation. Therefore, because it is spatially explicit and directly addresses population growth and viability, this approach provides a valuable foundation to planning conservation strategies, offering the ability to identify the most salient risks to viability and explore ways to address them.
Genetic Structure of Bat Populations
We developed new polymorphic nuclear microsatellite markers for Indiana bats and also tested them on gray bats, eastern small-footed myotis (M. leibii), little brown bats (M. lucifugus), and northern long-eard myotis (M. septentrionalis). These polymorphic microsatellite markers provide a valuable tool for investigating the population genetics of these species and will provide important genetic data useful for the conservation and recovery of the endangered Indiana bat.
Bonnot, T. W.; Thompson, F. R. III; Millspaugh, J. J.. 2011. Extension of landscape-based population viability models to ecoregional scales for conservation planning. Biological Conservation 144: 2041-2053.
Larson, M. A.; Thompson, F. R. III; Millspaugh, J. J. ; Dijak, W. D.; Shifley, S. R.. 2004. Linking population viability, habitat suitability, and landscape simulation models for conservation planning. Ecological Modeling 180: 103-118.
Millspaugh, J. J.; Thompson, F. R. III (eds.) 2009. Models for planning wildlife conservation in large landscapes. Burlington, MA. Academic Press. 688 p.
Reidy, J. L.; Thompson, F. R. III; Peak, R. G.. 2009. Factors affecting golden-cheeked warbler nest survival in urban and rural landscapes. Journal of Wildlife Management 73:407-413.
Thompson, F. R., III. 2009. Bridging the gap between habitat-modeling research and bird conservation with dynamic landscape and population models. In: Rich,T. D.; Arizmendi, C. ; Demarest, D.; Thompson, C. (eds.). Tundra to Tropics connecting birds, habitats and people. Proceedings of the Fourth International Partners in Flight Conference. 13-16 February 2008, McAllen, TX: Partners in Flight.
Trujillo, R.; Amelon, S. 2009. Development of microsatellite markers in Myotis sodalist and cross-species amplification in M. gricescens, M. leibii, M. lucifugus, and M. septentrionalis. Conservation Genetics 10:1965-1968.
- Sybill Amelon, Research Wildlife Biologist, US Forest Service- Northern Research Station
- Frank R. Thompson III, Research Wildlife Biologist, US Forest Service- Northern Research Station
- Thomas W. Bonnot, Department of Fisheries and Wildlife Sciences, University of Missouri, Columbia, MO
- Joshua J. Millspaugh, Department of Fisheries and Wildlife Sciences, University of Missouri, Columbia, MO
- Jennifer Reidy, Department of Fisheries and Wildlife Sciences, University of Missouri, Columbia, MO
- Lori Eggert, Division of Biological Sciences, University of Missouri, Columbia, MO
- Lisa O’Donnell, Balcones Canyonlands Preserve, City of Austin, TX
- Rebecca Peak, U. S. Army, Fort Hood, TX
- Todd Jones-Farrand, U.S. Fish and Wildlife Service, Columbia MO
Last Modified: 01/24/2012