The use of distance sampling and mark‐resight to estimate the local density of wildlife populations

Abstract

AbstractWe used distance sampling (line transects) and mark‐resight to estimate habitat and local area (area size, range: 3.9–44.5 ha) population density of ungulates. The distance sampling study was performed on fallow deer (Dama dama), roe deer (Capreolus capreolus) and wild boar (Sus scrofa) in a mediterranean forest. The mark‐resight study was performed on a roe deer population in a hilly area of the Apennines. The first study allowed us to estimate the animal density into four different habitats (deciduous oak wood, evergreen oak wood, maquis and open areas with domestic‐pine woods). The between habitat differences of population density are large for the three species: fallow deer are more abundant in the open areas (22.22 heads/km2, c.i. 12.42–39.74), roe deer in the deciduous oak wood (14.50 heads/km2, c.i. 7.01–30.10) and wild boar in both the open areas (11.29 heads/km2, c.i. 4.86–26.20) and evergreen oak wood (10.42 heads/km2, c.i. 6.78–16.02). The roe deer population in the Apennines is characterized by large between‐zone variations of population density (range: 1997: 13.25–131.31, 1998: 29.06–78.01, 1999: 10.67–88.58). Moreover, trends of local zones may be quite different with respect to the average trend of a wider study area, suggesting a well‐defined short‐scale spatial structure for this population. We conclude that both survey methods may be very useful in population assessment, but they need intense field effort and careful statistical design. Care needs to be taken to satisfy the assumptions of the statistical models. Copyright © 2002 John Wiley & Sons, Ltd.