Myotis ciliolabrum
(Merriam, 1886)

mI-O-tis sil-E-O-lA-brum

An adult Western Small-footed Myotis.

The Western Small-footed Myotis is the smallest Myotis in Kansas, and it is both rare and local in occurrence. It can be distinguished from other bats in Kansas by its small size, yellowish-brown dorsal fur, pale buff to whitish ventral fur, dark brown to blackish wing membranes, and black face mask and ears.

The western small-footed myotis occurs in western North America from southern Canada in the north to central Mexico in the south. In Kansas, this species has been found only in Cheyenne, Gove, Logan, and Trego counties, all in the west.
Fossils identified as this species were reported from a late Pleistocene cave deposit in Wyoming.

(, Museum Voucher) (, Observation) (, Literature Record)
Open icons are questionable records; Click on a marker to view details.
  • Occurrence Summary:  
  • 42 Total Records 
  • 42 Museum Vouchers 
  • 0 Other Observations 
Some county occurrences indicated below may be too imprecise to map above.
County Breakdown: County Name (# occurrences):
Cheyenne (1); Gove (16); Logan (15); Trego (10);

Natural History:
The natural history of the western small-footed myotis is poorly known. It seems to be a highly specialized "saxicolous" species, which means it roosts almost exclusively in rock crevices, caves, and tunnels, although occasional individuals are found in abandoned swallow nests, under loose pine bark, under bridges, or in abandoned buildings. In Kansas, it roosts are in bluffs and badlands associated with the Niobrara Formation and in canyon walls consisting of compacted Pleistocene loess. Many roost sites have been found by paleontologists searching for fossils. In Kansas and elsewhere, most localities of record for this species are in desert, badland, or semiarid habitats. The species is thought to be migratory (all records from Kansas are for the period May through September), but where they go is not known. Researchers in other states have reported individuals hibernating in cracks, crevices, and caves near their summer roosts. These bats are slow, highly maneuverable fliers as they seek flying insects. Not much else is known about this species.
Adults may attain the following dimensions: total length 80-99 mm; length of tail 37-49 mm; length of hind foot 6-9 mm; length of ear 12-16 mm; weight 3.3-5.9 g. Longevity in this species evidently has not been documented.
The diet of the western small-footed myotis is poorly known. Moths, beetles, flies, and caddisflies have been found in the guts of the few specimens thus far studied. All these prey presumably are taken on the wing relatively close to the ground.
Predation on this species has not been documented.
Because of its rarity, little is known about reproduction in this species. It generally gives birth to a single young, although one apparent case of twins has been reported. Young are born in June or July. Females with young generally roost alone by day, although a few small maternity colonies have been found.

Occurrence Activity:
Studies conducted in other states suggest that this bat species is declining. To prevent this from happening in Kansas, this bat should be added to the list of SINC species.
The nomenclatural history of this species is complex, the names Myotis subulatus and Myotis leibii having been applied to this bat in the past. The subspecific name for populations that occur in Kansas is Myotis ciliolabrum ciliolabrum.

1886 Merriam, C. H. Description of a new species of bat from the western United States. Proc. Biol. Soc. Washington, 4:1-4. ():
1952 Cockrum, E. L. Mammals of Kansas. Univ. Kansas Publ. Mus. Nat. Hist. 7:1-303. ():
1967 Jones, J. K. Jr., E. D. Fleharty, and P. B. Dunnigan The distributional status of bats in Kansas. Univ. Kansas Mus. Nat. Hist. Misc. Publ., 46:1-33. ():
1977 Robbins, L. W., M. D. Engstrom, R. B. Wilhelm, and J. R. Choate Ecogeographic status of Myotis leibii in Kansas. Mammalia, 41:365-367. ():
1983 Jones, J. K., Jr., D. M. Armstrong, R. S. Hoffmann, and C. Jones University of Nebraska Press, Lincoln, NE. 1-379pp.
1994 Fitzgerald, J. F., C. A. Meaney, and D. M. Armstrong University Press of Colorado, Niwot, CO. 1-467pp.
1999 Wilson, D. E., and S. Ruff Smithsonian Institution Press, Washsington, DC. 1-750pp.
2000 Sparks, D. W., and J. R. Choate Distribution, natural history, conservation status, and biogeography of bats in Kansas Pages 173-228 in Reflections of a Naturalist: Papers Honoring Professor Eugene D. Fleharty Fort Hays State University, Hays, KS. pp.
2001 Holloway, G. L., and R. M. R. Barclay Myotis ciliolabrum Mammalian Species 670():1-5
2008 Timm, R. M., G. R. Pisani, J. R. Choate, N. A. Slade, G. A. Kaufman, and D. W. Kaufman http://www.ku.edu/~mammals, . pp.
Account Last Updated:
8/21/2018 7:54:47 PM

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