The North American bat that winters in Central America and the southwestern United States after summering farther north is the hoary bat.
The hoary bat (Lasiurus cinereus) is a long-distance migrant found across much of North America. In spring and summer, it ranges into northern parts of the United States and Canada, where it hunts flying insects, often over woodland edges, lakes and open spaces. As conditions change in autumn, many individuals move south to wintering areas in Central America and the southwestern United States.
Its name refers to the frosted or grayish-white tips on its dark fur, which give the coat a hoary appearance. Hoary bats usually roost alone in foliage rather than forming the large cave colonies associated with some other bats. Moths are an important part of their diet, and an individual can forage over substantial distances.
The species is sometimes confused with the little brown bat or silver-haired bat because all are widespread North American insect-eaters. Migration is the key clue here: the hoary bat is especially notable for its broad seasonal movements. Migration can also expose it to hazards, including collisions with tall structures and wind turbines.