Daniel P. Reinhart D.J. Mattson 1996 <p><span>We investigated occupied squirrel middens and squirrel sightings and vocalizations as indicators of red squirrel (Tamiasciurus hudsonicus) abundance in the high-elevation whitebark pine (Pinus albicaulis) zone. Data were collected 1984-1989 from line transects located on 2 study sites in the Yellowstone ecosystem. We evaluated the performance of each measure on the basis of precision and biological considerations. We concluded that, of the 3 measures, active middens were the best indicator of red squirrel abundance. We also observed that the density of active middens dropped by 48%-66% between 1987 and 1989, following a severe drought and extensive wildfires that burned one of the study sites during 1988.</span></p> application/pdf en Monte L. Bean Life Science Museum, Brigham Young University Indicators of red squirrel (Tamiasciurus hudonicus) abundance in the whitebark pine zone article