How can dispersal benefit wolf populations?

Dispersal is beneficial to wolves-it is a way of mixing genes in the wolf population, of reducing inbreeding and sharing traits over broad geographical ranges (Steinhart, 1995). Inbreeding is a threat to packs because it leads to the loss of genetic variability needed for immunity to disease, and also leads to inbreeding depression from reduced fertility, and from increasing the possibility of gene mutations and deformity (Steinhart, 1995). Extra-pair copulations are important in populations where opportunities for dispersal are limited, which results in many kin in the same pack (Sillero-Zubiri, 1994).

Ensuring some diversity among a wolf pack also aids in the avoidance of disease. An isolated pack would be much more vulnerable to disease, leading to the termination of the entire pack. Rabies, for example, is a viral disease affecting the nervous system, causing altered behavior, paralysis, and death in most mammals. It can be easily transmitted between animals through a bite wound, by ingestion of infected material, or by inhalation of contaminated air (Chapman, 1978). Because members of wolf packs are socially close, if one member of a pack becomes rabid, most if not all pack members will be exposed and the pack risks decimation. In northeast Alaska, a rabid wolf was killed after behaving dangerously mad and out of control, and approximately 4 weeks later 6 dead wolves were found in the same area, all rabies-positive (Chapman, 1978).

This is evidence of how an entire pack can decimate itself and it supports the importance of dispersal between packs. It is critical for the success of reintroduction that wolf packs are not isolated. Dispersal between reintroduced packs and present native packs is important to increase genetic variability, reduce the risk of inbreeding, and avoid the threat of disease.

return to Social Structure & Dispersal

return home