Minimale Stichprobengröße für Berechnungen von Kernel-basierten ­Aktionsräumen beim Dreizehenspecht (Picoides tridactylus)

Abstract

Summary Minimum sample size for kernel based home‐range calculation in the Three‐toed Woodpecker (Picoides tridactylus) We developed a statistical model to determine the minimum sample size for kernel‐based home‐ranges in the Three‐toed Woodpecker (Picoides tridactylus). Between April and August 1998, 842 biologically independent observations of eight radio‐tracked Three‐toed Woodpeckers were made in Berchtesgaden National Park. Processing the resultant data with the telemetry‐software Ranges V, we calculated individual home‐ranges based on 95 % utilisation distribution for three biological periods (pre‐nesting, nesting, post‐nesting). We ascertained the minimum sample size for the kernel estimation developing a statistical trend model. The results showed that in the case of the Three‐toed Woodpecker home‐range estimations by the adaptive kernel method can be considered reliable presupposing a minimum sample size of 30 independent observations distributed evenly throughout a given period.