A Sightability Model for Bighorn Sheep in Canyon Habitats

Evaluation of an unmanned aircraft system for detecting surrogate caribou targets in Labrador

“…During aerial surveys, it is very difficult to see wildlife in forested areas because of direct canopy cover, and the obscuring effect of shadows. To address these issues, researchers have developed sightability models to account for visibility bias (Bodie et al 1995;Pearse et al 2008;Rice et al 2009;) and have also resorted to technological solutions, e.g. thermal infrared sensing (Dunn et al 2002;Potvin and Breton 2005).…”

Restoration of bighorn sheep metapopulations in and near 15 national parks: Conservation of severely fragmented species; Volume II, Synopsis of research findings

“…The National Park Service requires more accurate census techniques for bighorn sheep. Based upon input received from park units during the planning stage in 1991 and 1992 the Idaho sightability model (Unsworth et al 1994, Bodie et al 1995 was selected for development in Badlands and Canyonlands National Parks. These parks needed a technique that could detect a 15%-20% decline in numbers ofbighorn sheep in a source population.…”

“…The authors stress that these census estimates are provisional only. The work conducted to date suggests that sighting conditions vary between Badlands and Canyonlands study sites, and in turn, both of these study sites differ in sighting conditions from the Owyhee Canyon area of Idaho where the bighorn model was originally developed (Bodie et al 1995). The authors recommend that model development continue until a minimum of 80 data points have been gathered for each study area.…”

Determining factors affecting carcass removal and searching efficiency during the post-construction monitoring of wind farms.

“…Such variable-weighted models have not yet been applied to wind farm environmental assessments, however they have been used in other studies to predict visibility bias and sightability of elk and big horn sheep (Sightability models -Samuel et al 1987;Steinhorst et al 1989;Unsworth et 21 al. 1990;Otten et al 1993;Bodie et al 1995;Anderson et al 1998;Noyes et al 2000).…”

“…It is extremely important, therefore, to understand to what degree each variable affects searcher efficiency. Even though these correction factors have not been used yet in wind farm assessment, studies have been conducted in other areas which create variable-weighted models in order to predict realistic numbers of importance (Samuel et al 1987;Steinhorst et al 1989;Unsworth et al 1990;Otten et al 1993;Bodie et al 1995;Anderson et al 1998;Noyes et al 2000).…”