Genetics, environment, and subspecies differences: the case of Polites sabuleti (Lepidoptera: Hesperiidae)

Circumstantial evidence is presented that suggests the Mourning Cloak undergoes regular seasonal up- and downslope movements in northern California. The species breeds at low elevations in spring and then disappears until autumn; its disappearance coincides with the appearance of fresh individuals in the Sierra Nevada alongside obvious hibernators.