THE EFFECTS OF HABITAT FRAGMENTATION ON DEMOGRAPHY AND ON THE LOSS OFGENETIC-VARIATION IN THE RED SQUIRREL

A major problem in conservation biology is the extent to which the los s of genetic variability in isolated populations reduces their chance of survival. We present data in which the loss of genetic diversity in small and isolated populations can be directly related to population dynamics. Genetic similarity in red squirrels is inversely correlated with population size. The loss of genetic variation and the lower popu lation densities in isolated populations are both the result of reduce d immigration. Our data suggest that population processes rather than genetic problems are the real threat to small squirrel populations.