104 
PROCEEDINGS OF THE CALIFORNIA ACADEMY OF SCIENCES 
Series 4, Volume 65, Supplement I 
(Ammerman et al., 2016). The eastern small-footed myotis retained the name M. leibii and the 
western small-footed myotis was justifiably designated with the name combination of Myotis cili¬ 
olabrum. Van Zyll de Jong (1984) also recognized two subspecies of the western small-footed 
myotis, M. ciliolabrum ciliolabrum and M. ciliolabrum melanorhinus, based on earlier usage (Mer- 
riam, 1886) of the subspecific names as specific epithets (then placed within the genus Vespertilio ). 
The nomenclature for M. ciliolabrum thus has been widely recognized for over 30 years (for 
example, Holloway and Barclay, 2001). A possible mistake in the interpretation of van Zyll de 
Jong’s (1984) paper (which clearly listed the subspecies as M. ciliolabrum ciliolabrum and M. cil¬ 
iolabrum melanorhinus) split Myotis ciliolabrum into two species-level names: M. melanorhinus 
west of the Rocky Mountains and M. ciliolabrum east of the Rocky Mountains (Simmons, 2005), 
but with no biological or nomenclatural justification for this division. For Myotis ciliolabrum, Sim¬ 
mons (2005) states “Formerly included in leibii (for which Hall [1981] used the name subulatus), 
but see van Zyll de Jong (1984). Does not include melanorhinus’, see van Zyll de Jong (1984). 
Reviewed by Holloway and Barclay (2001), but note that they included melanorhinus as a sub¬ 
species of ciliolabrum .” However, van Zyll de Jong (1984) gives M. ciliolabrum melanorhinus and 
M. ciliolabrum ciliolabrum as subspecific names and does not raise them to the species level, con¬ 
trary to S imm ons’ (2005) interpretation. Bradley et al. (2014) do not include the name M. 
melanorhinus in their list of North American mammals. To our knowledge the nomenclature used 
by Holloway and Barclay (2001) is correct, and for this report we only consider the name M. cili¬ 
olabrum as valid for the species. Although there is no biological or nomenclatural basis in the pub¬ 
lished literature for the distinction and consequent elevation of the name M. melanorhinus, this new 
usage has appeared in a field guide (Kays and Wilson, 2009) and elsewhere. The field guide also 
gives the Continental Divide as demarcation of the two seemingly incorrectly designated species, 
but in many areas the Continental Divide extends down to habitats that are well used by this bat 
and does not constitute a continuous biological barrier. Holloway and Barclay (2001) provide a full 
taxonomic synonymy of past scientific names applied to the western small-footed myotis. 
The generic name originates with Greek words meaning “mouse” and “ear”. The specific 
epithet stems from Latin words meaning “eyelash” and “lip”. Other common names include west¬ 
ern small-footed bat, hairy-lipped bat, small-footed bat, black-nosed bat, Say’s bat, and La Grulla 
brown bat. 
Habitats and Relative Abundance.— In much of its range, the western small-footed 
myotis seems most abundant in forest and woodland habitat, although it is also found in lower-ele¬ 
vation habitats including the high plains in the Texas panhandle and rocky eroded terrain and bad¬ 
land cliffs in northeastern Colorado (Cary, 1911; Armstrong et al., 2011; Ammerman et al., 2012a). 
Potential exists for this species to be under-represented in capture samples from some regions due 
to difficulty distinguishing it from the California myotis. The California myotis is often presumed 
to be more abundant than the western small-footed bat in areas where they both occur, possibly 
resulting in reporting bias if western small-footed bats are not carefully identified and are erro¬ 
neously assumed to be the more common species. 
Pacific Northwest and Northern Rocky Mountains: Oregon, Washington, and British 
Columbia : Western small-footed myotis were of lower abundance in surveys over streams and 
ponds in Douglas fir-western hemlock forests across the western Cascade Mountains in southern 
Washington and the Oregon Coast Range, ranking seventh among 12 species (five bats among 241 
individuals); they were more abundant among bats captured in the eastern Cascades, ranking first 
among 49 individuals of five species with 18 captured (Thomas, 1988). They ranked ninth in rela¬ 
tive abundance (six bats sampled among 413 individuals of 11 species) of individuals collected for 
stomach contents analysis in arid scrubland and forest habitats of eastern Oregon (Whitaker et al., 
