A Helicopter Quadrat Census for Mule Deer on Uncompahgre Plateau, Colorado
| Autor: | Roland C. Kufeld, David C. Bowden, James H. Olterman |
|---|---|
| Rok vydání: | 1980 |
| Předmět: |
education.field_of_study
Ecology biology Population Census Odocoileus Simple random sample biology.organism_classification Stratified sampling Altitude Geography General Earth and Planetary Sciences Physical geography Quadrat education Transect Ecology Evolution Behavior and Systematics Nature and Landscape Conservation General Environmental Science |
| Zdroj: | The Journal of Wildlife Management. 44:632 |
| ISSN: | 0022-541X |
| DOI: | 10.2307/3808010 |
| Popis: | Mule deer (Odocoileus hemionus) were censused by 2 observers in a helicopter during 3 consecutive winters on 193 0.6475-km2 quadrats distributed, in a stratified random sampling design, throughout 1,688 km2 of pinyon-juniper (Pinus edulis-Juniperus osteosperma) winter range on the Uncompahgre Plateau, in southwestern Colorado. Quadrats were plotted on maps and aerial photos, and the 4 corners were permanently marked on the ground. Estimates of total deer population and 90% confidence limits for the 3 years were 11,401 + 2,205, 17,884 + 4,042, and 17,085 ? 2,951, respectively. During the 2nd and 3rd years the sample was sufficient to permit estimation of the population within 22.6 and 17.3% of the mean number of deer per 2.59 km2, respectively, with 90% confidence. Stratified random sampling reduced variance of the mean number of deer seen per 2.59 km2 by 42, 21, and 37%, respectively, relative to simple random sampling during the 3 years of the census. Procedures for conducting a census of this type and methods for minimizing observer error are detailed. J. WILDL. MANAGE. 44(3):632-639 This study was initiated as a result of widespread concern among wildlife managers and the public that Colorado mule deer populations had suffered recent declines. These declines could not be documented, however, due to lack of deer census systems that had been implemented and tested on a large scale (Gill 1976, Wallmo et al. 1976). The need for such a census sytem was, therefore, clearly recognized. Mountainous terrain and relative inaccessibility of many areas in the West compound problems of censusing deer. A technique employing a helicopter to survey randomly located quadrats was selected for assessment of feasibility because it appeared to offer a reasonable solution to those problems. Numerous studies have evaluated aerial census systems for large ungulates. Many of these have involved counting African animals along transects (Goddard 1967, Bell et al. 1973, Norton-Griffiths 1973). Bergerud (1963) used the transect method to count caribou (Rangifer tarand s) in Newfoundland and Labrador, and Caughley et al. (1976) used it in Australia to count kangaroos (Megaleia rufa, Macropus giganteus and fuliginosus) and domestic sheep. The transect system is suited only to use in relatively flat terrain, however, because counting errors occur in mountainous terrain due to variations in altitude and banking the aircraft, which affect definition of the transect strip (Pennycuick 1969). Big game animals on quadrats can be censused using a helicopter in the steepest mountain |
| Databáze: | OpenAIRE |
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