The estimation of wildlife ungulate abundance using sample area surveys: an application to Maremma Regional Park

Sample surveys for estimating the abundance of wildlife ungulate populations are considered in a design-based approach. On the basis of previous theoretical results, a two-stage sampling is proposed. In the first stage, some spatial units are selected using Lahiri-Midzuno sampling, while in the second stage, the animal abundance in the selected units is estimated by means of plot sampling performed on the faecal accumulation within the units. The statistical properties of the resulting ratio estimator of abundance are outlined. An application of the proposed method for estimating fallow-deer and roe-deer abundance in Maremma Regional Park is described.