Caribou Monitoring of the Mentasta Herd in Wrangell-St. Elias National Park and Preserve, Alaska.
Putera J, Jenkins K, Reid M. Caribou Monitoring of the Mentasta Herd in Wrangell-St. Elias National Park and Preserve, Alaska.. 1988. National Park Service
The CAKN has adopted a holistic view of network ecosystems and will track the major physical drivers of ecosystem change. Caribou are an important component of the ecosystem. Together with moose, sheep, and smaller prey they help support a diverse mix of predators and scavengers including wolves, brown bears, black bears, golden eagles, foxes, coyotes, and wolverines. All are important to the functioning of a natural ecosystem that includes humans. Caribou herd size estimates are generally derived from fixed-wing or helicopter aerial surveys, either by directly counting animals that are observed or by photographing post-calving aggregations. The photocensus approach is most effective for the larger caribou herds that form dense aggregations during late June and early-July. Generally, population estimates derived from either type of aerial survey are minimum counts, commonly inflated by a subjective estimate of the number of caribou that were missed during the survey. For the two herds in Wrangell-St. Elias (WRST) National Park and Preserve estimates in the past 5 years have been primarily derived from aerial surveys using the sightability-model approach to account for individuals missed during the surveys and to estimate the number of caribou outside the survey area based on detection and distribution of radiocollared animals during the surveys. These approaches provide objective estimates of herd size with measures of precision and will continue to be used in WRST. Additionally, for small caribou herds like those to be monitored in WRST, calf recruitment is an important determinant of population trend and will be assessed annually by determining calf:cow ratios during fall composition surveys. These fall surveys also provide estimates of adult sex ratios, important for guiding harvest management decisions. Adult female survival is also an important vital rate contributing to herd trends and will be estimated by regular monitoring of radiocollared individuals. The measurable objectives are to determine population size and trend of the Mentasta and Chisana caribou herds, estimate calf recruitment and adult sex ratios for these herds, estimate annual adult female survival, document seasonal distribution of caribou from these herds throughout the year, obtain estimates of exposure for selected diseases from serological analyses, and assess trends in mass and body size of adult females. Caribou surveys are conducted aerially with small, tandem fixed wing and or rotary aircraft. Mentasta caribou herd size is estimated by combining results from a June postcalving survey and a September sex and age composition count while Chisana caribou herd estimates are obtained in October. Radiocollaring generally occurs in the fall in association with composition counts. Radiotracking flights will occur seasonally thoughout the year.
- Type
- Project
- Authors
- Putera, Judy; Jenkins, Kurt; Reid, Mason
- Publisher
- National Park Service
- Units
- CAKN , WRST
- Keywords
- Abundance, Alaska, barren-ground caribou, Body Condition, Body mass, calf, Caribou, Distribution, Mentasta herd, Mortality, Nelchina herd, Population, Range, Rangifer tarandus, Survival, Wildlife
- Subjects
- Ecological Framework: Biological Integrity | Focal Species or Communities | Mammals