Track: Ecology, Conservation, and Archaeology
Tortoise Landscapes - A Habitat Suitability Model for the Threatened Desert Tortoise
Gillian BowserMichael Rock , Brent Long
The desert tortoise, Gopherus agassizzi, is listed as threatened under the Endangered Species Act. Joshua Tree National Monument, an 800,000-acre park in the California desert, designed a GIS model using known tortoise locations and environmental parameters (measured both in the field and from digital data). The model creates a layer that represents tortoiseness - a grid of cells with values of tortoise preferences. This layer is then used to assign values (using coefficients from logistic regression) to a surface that represents areas of predicted tortoise preference. Field work was based on validating the model by comparing observed values (field data) to predicted values from the model. Management implications and uses are discussed.
Gillian Bowser
Joshua National Park
74485 National Park drive
29 Palms, CA 92277
USA
Telephone: 760-367-5562
Fax: 760-367-6392
E-mail: Gillian_Bowser@nps.gov