Myotis yumanensis
(H. Allen, 1864)

mI-O-tis yU-man-en-sis

An adult Yuma Myotis.

This is a medium-sized, small-eared, pale grayish to yellowish bat, its dark membranes contrasting fairly strongly with the fur. Among Kansas species of Myotis, only the Small-footed Myotis are as pale in color. The small-footed myotis is more yellowish, less grayish and it is smaller than the Yuma myotis. Total length is 86-88 mm; length of forearm, 34-38 mm; and wingspan, about 235 mm. Weight ranges from 3 to 5 g.

Known only from eight specimens taken on 27 and 28 August 2008 in the vicinity of Bear Creek north of Saunders in Stanton County. Another specimen was captured by KDWP in Morton County in 2019 and tentatively identified as a Yuma Myotis. Wing punches were obtained, but no voucher specimen was collected. See "Remarks" below for details.

(, Museum Voucher) (, Observation) (, Literature Record)
Open icons are questionable records; Click on a marker to view details.
  • Occurrence Summary:  
  • 8 Total Records 
  • 7 Museum Vouchers 
  • 1 Other Observations 
Some county occurrences indicated below may be too imprecise to map above.
County Breakdown: County Name (# occurrences):
Stanton (8);

Natural History:
This is a species of dry shrubby country. Typical habitat is in pinon-juniper woodland and riparian woodland in semi desert valleys. The animals roost in caves, crevices or abandoned buildings and other structures. They forage over water, along streams, over springs, among riparian or shoreline vegetation. In Colorado the Yuma Myotis apparently does not hibernate, however its winter haunts are unknown. They arrive in Colorado about April, and they become scarce in September.
Food consists mostly of moths, flies and beetles, but also includes leafhoppers, caddisflies, lacewings and craneflies. The animals forage near water and take many aquatic insects. They are efficient feeders and can fill their stomachs in 15 to 20 minutes. They forage in early evening, usually along the main channel of a stream.
In Colorado, where they are more widespread, breeding has not been studied much, however lactating females have been captured and a nursery colony was discovered in 1990 in the Colorado National Monument. Elsewhere, the animals are known to form nursery colonies of upwards of several thousand individuals in caves or attics. Apparently all adult females in a population breed. A single young is born late in the spring or early in the summer. Small breeding colonies have been discovered in the southeastern part of Colorado, but not elsewhere in Colorado. Males are solitary as the young are reared.

Occurrence Activity:
A few bats tentatively identified as this species were collected in Stanton County. Tissues were sent to Texas Tech University for DNA analysis to check the identification. If the bats represent Myotis yumanensis, this account will be expanded and fleshed out. Mitochondrial DNA sequences also were analyzed at Fort Hays State University by one of the authors (LP) in 2021 and compared with sequences available in GenBank. Preliminary results have shown that these individuals likely are Myotis velifer. Another individual was captured by KDWP in Morton County in 2019. Analysis of wing punches showed similar results. We will await the collection of more data, further sequencing, and publication of results before making a confirmation. This species will remain as "questionable" in Kansas until such time.

1959 Hall, E. R., and K. R. Kelson Ronald Press, New York. 2 volumespp.
Account Last Updated:
9/2/2021 10:39:52 AM

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