Abstract
We examined seasonal changes in coat color in the Japanese marten, Martes melampus, in the southern Kyushu District. Color changes were seen in April and in November both in the field and in the laboratory. The head color of captive male turned white in the laboratory when the room temperature was dropped from 28°C to 16°C and the duration of daytime was reduced from 11.5 hr to 10.5 hr. Head color turned black when the temperature was elevated from 18°C to 25°C and the duration of daytime was elongated from 12.5 hr to 13.5 hr. Color changes in spring and in autumn proceeded respectively in opposite directions. Winter color became reduced in degree from high latitudes to low latitudes, and the coloration of the rostrum or fringes of the eyes remained black year-round in Kyushu.
