Geology ReportsSearch

Geology topics

William E. Van Pelt

Publications and source records attributed to William E. Van Pelt.

3 recordsLinked to original sources

Assessing range-wide habitat suitability for the Lesser Prairie-Chicken

Population declines of many wildlife species have been linked to habitat loss incurred through land-use change. Incorporation of conservation planning into development planning may mitigate these impacts. The threatened Lesser Prairie-Chicken ( Tympanuchus pallidicinctus ) is experiencing loss of native habitat and high levels of energy development across its multijurisdictional range. Our goal was to explore relationships of the species occurrence with landscape characteristics and anthropogenic effects influencing its distribution through evaluation of habitat suitability associated with one particular habitat usage, lekking. Lekking has been relatively well-surveyed, though not consistently, in all jurisdictions. All five states in which Lesser Prairie-Chickens occur cooperated in development of a Maxent habitat suitability model. We created two models, one with state as a factor and one without state. When state was included it was the most important predictor, followed by percent of land cover consisting of known or suspected used vegetation classes within a 5000 m area around a lek. Without state, land cover was the most important predictor of relative habitat suitability for leks. Among the anthropogenic predictors, landscape condition, a measure of human impact integrated across several factors, was most important, ranking third in importance without state. These results quantify the relative suitability of the landscape within the current occupied range of Lesser Prairie-Chickens. These models, combined with other landscape information, form the basis of a habitat assessment tool that can be used to guide siting of development projects and targeting of areas for conservation.

Colorado, Kansas, New Mexico, Oklahoma, Texas

The innate immune response may be important for surviving plague in wild Gunnison's prairie dogs

Prairie dogs (Cynomys spp.) are highly susceptible to Yersinia pestis, with ≥99% mortality reported from multiple studies of plague epizootics. A colony of Gunnison's prairie dogs (Cynomys gunnisoni) in the Aubrey Valley (AV) of northern Arizona appears to have survived several regional epizootics of plague, whereas nearby colonies have been severely affected by Y. pestis. To examine potential mechanisms accounting for survival in the AV colony, we conducted a laboratory Y. pestis challenge experiment on 60 wild-caught prairie dogs from AV and from a nearby, large colony with frequent past outbreaks of plague, Espee (n = 30 per colony). Test animals were challenged subcutaneously with the fully virulent Y. pestis strain CO92 at three doses: 50, 5,000, and 50,000 colony-forming units (cfu); this range is lethal in black-tailed prairie dogs (Cynomys ludovicianus). Contrary to our expectations, only 40% of the animals died. Although mortality trended higher in the Espee colony (50%) compared with AV (30%), the differences among infectious doses were not statistically significant. Only 39% of the survivors developed moderate to high antibody levels to Y. pestis, indicating that mechanisms other than humoral immunity are important in resistance to plague. The ratio of neutrophils to lymphocytes was not correlated with plague survival in this study. However, several immune proteins with roles in innate immunity (VCAM-1, CXCL-1, and vWF) were upregulated during plague infection and warrant further inquiry into their role for protection against this disease. These results suggest plague resistance exists in wild populations of the Gunnison's prairie dog and provide important directions for future studies.

Arizona

Population differences in host immune factors may influence survival of Gunnison's prairie dogs ( Cynomys Gunnisoni ) during plague outbreaks

Over the past 40 yr, epizootics of plague ( Yersinia pestis ) in northern Arizona have reduced populations of the Gunnison’s prairie dog ( Cynomys gunnisoni ), with the exception of a large population found in the Aubrey Valley (AV). To examine potential mechanisms accounting for their survival, we collected prairie dog serum samples in 2005–2006 from AV and a neighboring population near Seligman (SE), Arizona. We quantified gene expression at 58 diverse immune proteins using a multiplexed enzyme-linked immunosorbent assay panel. We found a subset of proteins important in coagulation and inflammation (tissue factor [TF], calbindin [Cal], and thrombopoietin [TPO]) and T-cell responses (CD40L and CD40) that were present in AV at levels two to eight times greater than SE. These results suggest that AV and SE animals might differ in their ability to mount an immune response.

Arizona