A Double-Observer Method for Reducing Bias in Faecal Pellet Surveys of Forest Ungulates
Jenkins KJ and Manly BF. 2008. A Double-Observer Method for Reducing Bias in Faecal Pellet Surveys of Forest Ungulates. Journal of Applied Ecology. 45(5):1339-1348
From the Summary: "1. Faecal surveys are used widely to study variations in abundance and distribution of forest-dwelling mammals when direct enumeration is not feasible. The utility of faecal indices of abundance is limited, however, by observational bias and variation in faecal disappearnce rates that obscure their relationship to population size. We developed methods to reduce variability in faecal surveys and improve reliabiligy of faaecal indices. 2. We used double-observer transect sampling to estimate observational bias of faecal surveys of Roosevelt elk Cervus elaphus roosevelti and Columbian black-tailed deer Odocoileus hemionus columbianus in Olympic National Park, Washington, USA. We also modelled differences in counts of faecal groups obtained from paired cleared and uncleared transect segments as a means to adjust standing crop faecal counts for a standard accumulation interval and to reduce bias resulting from variable decay rates."
- Type
- Journal Article
- Authors
- Jenkins, K; Manly, B
- Units
- OLYM
- Keywords
- Columbia black-tailed deer (Odocoileus hemionus columbianus), dung counts, Modelling, Observer bias, Roosevelt Elk (Cervus elaphus roosevelti)