Die Körpergrösse des Rehes als Bioindikator

Abstract

If young roe deer get enough food in their first 8 months of life, they grow rapidly. Life weights range from below 10 kg to above 23 kg for roe deer kids in November. Under field conditions at Stammham (Bavaria) young roe deer grow as fast as farm animals until August, but slowlier from the time of September. There is nearly no growth from December until the end of May under range conditions, but about 4 kg of penned animals artificially fed, and even more of the young of penned females. — Retarded young animals do not catch up, even when kept in good feeding conditions.

So, mean body size of a population of roe deer is triggered by feeding conditions in the range, mainly from autumn to early spring. — A population of large body size is only possible, if the animals have had enough food of good quality. So they could not have damaged the vegetation. Body size of roe deer may be regarded as an indicator for a population (density), that makes not too much damage on young forest plantations.

A bone length is a better controle of body size than weights are, which differ in the same animal according to the season of the year. Adult roe bucks in W-Germany weigh (mean values in parenthesis) from 12 to 25 kg (about 15 kg) without viscera and organs of the body cavity (“Kg”), depending upon range conditions and density. Maximal length of the skull ranges from 180 to 220 mm (187 mm); skull bones of the trophy from 133 to 170 (145 mm); jaw bone from 141 to 172 mm (150 mm). These measures are highly correlated to each other and to body weight.

If skull length (mm) in relation to body weight $\sqrt[3]{{KG}}$ is regarded with allometric methods, the allometric exponent for one population (103 adult bucks, a = 0,651) is nearly equal to that of five different populations (n = 116, a = 0,673). That’s why skull length (or jaw bone length) is believed to be an indicator for the body sizes of roe deer populations in a very large area.

Range-related, the relative roe deer density in W-Germany must become smaller in many localities. It should be somewhere below carning capacity — for the benefit of the forests and of the deer. — It is believed to be possible to reach mean body sizes of adult (over 24 months old) roe bucks of 200 mm skull length (18–19 kg “Kg”) nearly everywhere in Germany by reducing population densities and/or making range conditions more favorable.

Regarding the body size of a roe deer population, management may become independent of the “knowledge” of population density. — Maybe hunters become interested in this project, for trophy quality grows with body size overproportionally.

Die grundlegenden Gedanken zu diesem Vortrag wurden gemeinsam mit Dr. D. Eisfeld, Inst.f.Tierphysiol., München, entwickelt.