A New Life Table and Population Models for the Desert Tortoise (Gopherus agassizii) in the Eastern Mojave Desert, California
Berry KH, Weinstein MN, White GC, Turner FB. 1994. A New Life Table and Population Models for the Desert Tortoise (Gopherus agassizii) in the Eastern Mojave Desert, California. Bulletin of the Ecological Society of America. 75(2):15
Using data spanning 13 years (1977-1990), we developed new growth and survivorship models and a new life table for tortoise populations in the eastern Mojave Desert. Growth was examined for males and females using 1467 pairs of records. Key determinants of growth rate were size and sex of tortoises and general availability of food and water. Survival rates, measured by the SURVIV program, varied considerably from year to year, e.g., 26.2-92.3% for 1-yr old tortoises. The new life table predicted that the initial cohort would fail to replace itself and the population is likely to decline at a rate of 2.9%/yr. Rainfall and food availability profoundly affect survival rates of juveniles and thereby success of the cohort.
- Type
- Journal Article
- Authors
- Berry, Kristin; Weinstein, Michael; White, Gary; Turner, Frederick
- Units
- MOJA
- Keywords
- Animal Studies