Frequent occurrence of partial albinism in lesser Japanese moles (Mogera imaizumii) on Kinkazan Island, Miyagi Prefecture, northeastern Japan

Forty lesser Japanese moles (Mogera imaizumii) were trapped on Kinkazan Island, which is a small island (959 ha) located 1 km off Honshu in northern Japan. Of these, 36 moles (90%) showed some degree of partial albinism of the fur, ranging from only small tufts of cream-colored hairs on their basal forefoot to multiple large interconnected patches spread around the whole body. Most tufts, spots and patches were cream-colored, but some tufts and spots on the lower abdomen were light brown. This coloration is attributable to staining by a secretion from skin glands that are distributed ventrally, with a higher density in the lower abdomen. The high frequency of partial albinism may be attributable to a lack of predators in this insular ecosystem or to low genetic diversity in the population, although it is difficult to know which of these two is more important.