Caclulation of size of home range [Calcul de la taille du domaine vital].

Résumé

The differing degree of intensity of use of the home range is a biologically significant aspect, and should not be neglected while attempting to determine absolute size. Theseveral methods which have been used in calculating size of home rnge are reviewed. Each method depends upon the assumption that an animal will be trapped throughout at least the biologically important portions of its home range. An experimental examination of this assumption is highly desirable. Trapping results may be stated in terms of the distribution of the points of capture about a center of activity, and a method of locating the center of activity is outlined.The probaility of capture by a single trap at various points throughout the home range might be a useful index to the trap-frequenting activity of an animal. However, usual trapping data relate to an animal within an entire set of traps, where traps in one part of the home range may interfere with captures in another part. The phenomenon of the trap-rvealed home range area increasing rapidl for the forst few captures and apparently "leveling off" with further captures has previuosly been explained solely on the assumption that the animal has reached the absolute limits of its home range. However, a similar tendency might result from the mechanics of trapping, and therefore observation of this phenomenon is not in itself proof that such absolute limits have been revealed. The relationship between true home range and trap-revealed range is especially in need of experimental analysis.