North Dakota's
Federally Listed Endangered, Threatened, and Candidate Species – 1995
Small-footed Myotis (Myotis ciliolabrum)
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- Status: Former Candidate (Note: As of February 28, 1996, this species is no longer listed as a Candidate species. However, it remains a species of management concern.)
- Historical Status:
- Unknown.
- Present Status:
- This species occurs throughout much
of the western United States, from southern Canada to northern Mexico.
- Habitat:
- The small-footed myotis is closely associated with rocky habitats throughout much of its distribution. On the Northern Plains it occurs most frequently in areas with dissected breaks and badlands, ridges, cliffs, or major outcroppings prevalent in western North Dakota, South Dakota, and Nebraska.
- Life History:
- In winter, the small-footed myotis is
known to hibernate in caves and mines. When hibernating, individuals seldom hang in the open, but rather secrete themselves in cracks and crevices, sometimes singly and sometimes in small groups. In summer, day roosts have been found in buildings, behind bark of pine trees, in rocky or eroded crevices and cracks, under rocks on the ground, and even in holes in banks and hillsides and in abandoned swallow nests. Night roosts in summer are typically in caves or mines, beneath rock ledges, and in man-made structures. Females give birth to a single offspring in July in the Northern Plains. Females and their young usually roost alone by day, although occasional small maternity colonies have been reported. The small-footed myotis is insectivorous. Their diet includes moths, flies, ants, and flying beetles, which are captured while in flight.
- Aid to identification:
- One of the smallest members
of the genus Myotis in the Plains states, the small-footed myotis has tiny feet, usually measuring about 1/4-3/8" (6-8 mm). The fur on this bat is light tan to golden brown above and buff to nearly white below. They also have dark ears and a black facial mask that aids in identification. Total length 2 3/4-3 1/4 (71-82 mm); tail 1 1/4-1 1/2" (30-38 mm); hindfoot 1/4-3/8" (6-8 mm); forearm l 1/4-1 1/2" (30-36 mm); weight 1/4 oz. (6-9 g).
- Reasons for decline:
- Present and threatened
destruction of habitat may be the most important factor concerning the existence of this bat. They are extremely vulnerable to mine closures, and the effects of disturbance from recreation at these sites. Just walking into a maternity colony may cause the female to drop her young. Frequent disturbance may cause the entire colony to abandon the roost. Pesticides and other environmental contaminants destroy their prey base. Bats are also known for loading of pesticides in their fat reserves.
- Recommendations:
- Notify a natural resources
agency on any suspected small-footed myotis sightings.
- Comments:
- The tolerance of this species for cold,
relatively dry places for hibernation is unusual for so small of a bat, thus it is one of the few bats known to hibernate in caves and mines in the West.
- References:
- Mammals of the Northern Great Plains by
J.K. Jones Jr et. al., 1983.
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