Population Dynamics of Tule Elk at Point Reyes National Seahore, California
Howell JA, Brooks GC, Semenoff-Irving M. 2000. Population Dynamics of Tule Elk at Point Reyes National Seahore, California. USGS- Western Ecological Research Center
The presence of locally abundant wildlife raises 4uestions among wildlife managers about natural regulation and ecological consequences of over population. The purpose of our study was to establish precise information about population size, structure, and productivity to examine the role of natural regulation in a closed tule elk (Cervus elaphus nannodes) population at Point Reyes National Seashore. We estimated an exponential growth rate of 0.19 with an adjusted R2 = 0.98, 20 years after the elk were introduced. We estimated survivorship for adult cows of nearly 0.95. Calf survivorship from birth through the rut ending in October-November was 0.85. Male calves exhibited higher mortality than female calves, while cow mortality we observed was associated with the calving season. We measured a 42% increase in cow calf density form 0333 ha to 1.043 ha in 1996 to 1998. We observed a density correlated reduction in the rate of increase and in the cow:calf ratios prior to high precipitation El Niflo years, 1993, 1996 and 1997, precipitation> 1023 mm yea(’. Given the high population growth rate and model evaluation of management scenarios, park managers will need to use a suite of approaches to maintain the elk population at levels at or near the closed range carrying capacity.
- Type
- Published Report
- Authors
- Howell, Judd; Brooks, George; Semenoff-Irving, Marcia
- Date of Issue
- 2000-08-20
- Publisher
- USGS- Western Ecological Research Center
- Units
- PORE
- Keywords
- Cervus elaphus nannodes, Point Reyes National Seashore, Population Dynamics, Tule elk, Wildlife Management