Skip to main content

Ralph Grundel

thumbnail
We investigated fine-scale genetic patterns of the federally threatened Eastern Massasauga Rattlesnake (Sistrurus catenatus) on a relatively undisturbed island in northern Michigan, USA. This species often persists in habitat islands throughout much of its distribution due to extensive habitat loss and distance-limited dispersal. These data are from 102 individual Eastern Massasauga Rattlesnakes sampled at Bois Blanc Island, Michigan and genotyped at 15 microsatellite loci. Samples were collected as part of a study to examine functional connectivity for the Eastern Massasauga. We found that the entire island population exhibited weak genetic structuring with spatially segregated variation in effective migration...
thumbnail
This scenario planning decision support tool for the Kankakee River basin as a first case study/proof-of concept. Hydrology models, both surface water and groundwater, and ecology of the Kankakee River watershed will be combined to evaluate the effects of habitat restoration on water suppy ecosystem services, agricultural irrigation demands, urbanization, and waterfowl habitat, and sportsman and recreational user interests. Various scenarios for restoration identified with peer input were tested for the watershed. Each scenario results in different individual and aggregate values for ground water recharge, surface water storage, waterfowl habitat, sportsman and recreational use, and agricultural capacity. Some...
thumbnail
Insects with morphologically different life stages can face a time tradeoff between foraging and egg-laying behavior when larval and adult resources are spatially segregated. Understanding this tradeoff in the Karner blue butterfly (Lycaeides melissa samuelis) can inform resource management for this federally endangered species under changing resource distribution and availability. We collected data on adult butterfly densities, larval (wild blue lupine, Lupinus perennis) and adult (nectaring plants) resource densities, and adult resource use. We defined “resource use” as anytime a butterfly was found (resting, crawling, feeding, laying eggs, mating) on a resource. Data were collected in eight habitat patches (10...
thumbnail
Bee-Gap describes the ecology, life-history, and distribution of 3,925 bee species in the United States that have geographical data and verified taxonomy. The database was constructed by compiling information from a broad range of internet sources and peer-reviewed journal articles. The 10 traits included in the database are: native status (native versus exotic/introduced), state and territory presence/absence, adult habitat, nesting strategy, voltinism, sociality, host bee species (for parasitic bees only), foraging strategy (generalist vs specialist), known host plants, and tongue length.
thumbnail
The dataset consists of abundance information of butterfly species (61 species) collected at 25 sites in northwest Indiana in 1998 and 1999. Each site was surveyed 21 times. Auxiliary data on environmental conditions were collected to allow us to relate habitat differences among sites to differences in abundance and composition of the butterfly community.
View more...
ScienceBase brings together the best information it can find about USGS researchers and offices to show connections to publications, projects, and data. We are still working to improve this process and information is by no means complete. If you don't see everything you know is associated with you, a colleague, or your office, please be patient while we work to connect the dots. Feel free to contact sciencebase@usgs.gov.