Description: The cave myotis is the largest myotis in Kansas. It can be distinguished from other bats in Kansas by: 1) drab brown dorsal color with the bases of the hairs dark, 2) underparts paler than the back, 3) ears short and pointed, and when laid forward they reach or extend only slightly beyond the nostrils, and 4) large size.
Size: Adults may attain the following dimensions: total length 99-111 mm; hind foot 11-13 mm; ear 15-16 mm; weight 9.7-15.5 grams.
Range and Habitat: The cave myotis is found in south-central and southwestern Kansas. As its name implies, it prefers to roost in caves, but when these are not available will use mines and buildings. In winter, large colonies of males and females hibernate together in cool caves with stable temperatures. The changing winter temperatures in southern Kansas may cause the cave myotis to move from one cave to another, but they are permanent residents of the gypsum caves in that region. Such movements have been determined by recovering bats with aluminum bands that have been placed on the forearm of their wings for identification. In summer, females move to warmer caves for rearing young.
Reproduction: Copulation takes place in October, but fertilization of ovulated eggs in the females reaches its height in April when the breeding females leave hibernation. After a gestation period of 60-70 days, females produce a single young in late June or early July which is maintained in a nursing cluster. At three weeks the young fly about the cave for short distances, and after six weeks they are weaned. By late August and early September the young are approximately the same size as adults.
Habits: One of the characteristics of the cave myotis is the clustering of many individuals on ceilings and walls of caves. Sometimes these clusters number more than a thousand, and many times in two or three layers of individuals. This behavior permits some regulation of temperatures within the cluster, and is especially beneficial for the young. In Kansas this bat hibernates or most of the winter, but may, on occasion, become active for short periods, especially if the cave does not have a low, stable temperature. During the period of summer activity they leave the cave to forage, usually a few minutes after sunset. They return to the cave later, but may forage again just before dawn.
Food: The cave myotis eats insects which are captured by echolocation. They are able to determine the size and form of insects, and distinguish objects such as limbs and leaves of trees. Foraging requires highly developed maneuverable flight and high metabolic energy, but the cave myotis, like other bats, has resolved the intricate flight and energy demands. Light wings and long slender fingers connected by a thin membrane of skin makes bats remarkably well-adapted to flight. These bats are opportunistic and feed on a wide variety of insects including beetles, moths, and true bugs. Ordinarily the chitinous hard parts of insects are not eaten.
Remarks: Males and females have an equal sex ratio and may live up to 10 or 15 years. The cave myotis is sometimes preyed upon by hawks, owls, raccoons, and other predators. It is believed that the long life of this bat is associated with the low rate of predation and periodic reduction of its metabolic rate. Identification bands, which require federal and state permits, have the address of the U. S. Fish and Wildlife Service. When a bat is found with such a band, this agency should be notified so that the bat's movement may by plotted.