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PROCEEDINGS OF THE CALIFORNIA ACADEMY OF SCIENCES 
Series 4, Volume 65, Supplement I 
the Black Hills of South Dakota as reproductive. Two of six females (33%) netted in southwestern 
North Dakota were reproductive (Genoways and Jones, 1972). In the panhandle of Nebraska, seven 
of 11 adult females (64%) were reproductive during 2010-2011 (Geluso and Geluso, 2016). 
Remarkably, the proportion of reproductive females among the cumulative total females taken over 
water over all U.S. locations and years was identical to the Alberta study, at 56% (96 of 172 bats). 
Natality at a maternity roost in San Luis Obispo County, California, was approximately 84% (16 
non-volant young and 19 adult females captured, two unknown sex adults escaped; Koford and 
Koford, 1948). Tuttle and Heaney (1974) found nine of 10 females (90%) roosting primarily soli¬ 
tarily to be reproductive at Badlands National Park in South Dakota. 
We are unaware of any published literature with quantitative data concerning other demo¬ 
graphic aspects of female reproduction, such as age at first reproduction and inter-birth intervals. 
Survival: We are unaware of any published literature with quantitative data on survival for 
this species. 
Mortality Factors: Mortality factors impacting western small-footed myotis are poorly 
known. Rabies infections have been documented (for example, Bogan and Cryan, 2000). Deaths 
due to entrapment in oil sludge pits in northwestern Colorado have been reported (Finley et al., 
1983). White-nose syndrome has not been reported for this species. Hamm et al. (2017) discovered 
actinobacteria (including Streptomyces ) with anti-fungal properties on wings of these bats and pos¬ 
tulated that actinobacteria may have defensive properties against the fungus that causes white-nose 
syndrome as it moves into western North America. He lmint hs and ectoparasites have been 
described (as summarized by Sparks and Choate, 2000 and Whitaker and Wilson, 1974; see also 
Lausen, 2005; Heddergott and Steinbach, 2015) but no associated mortality has been observed. 
Population Trend: Annual counts of western small-footed myotis at two hibemacula in New 
Mexico and South Dakota were analyzed for trends over time, but none were detected (Ellison et 
al., 2003). Species dynamic distribution models were constructed using Bayesian hierarchical mod¬ 
eling techniques for 12 species of bats in Washington and Oregon based on an eight-year monitor¬ 
ing program; bat activity was sampled with mist nets and acoustic detectors, and the analysis 
accounted for detectability and annual turnover in bat occurrence (Rodhouse et al., 2015). Western 
small-footed myotis did not show a decline in occurrence probabilities with time (Rodhouse et al., 
2015). 
Population Genetics: Lausen (2007) analyzed mitochondrial and nuclear DNA of 486 west¬ 
ern small-footed myotis from prairies of Alberta to investigate genetic aspects of population struc¬ 
ture, relatedness, and dispersal. Populations in that study region were highly structured and showed 
limited dispersal. Although the study did not directly address genetic diversity concerns, no pres¬ 
ent-day loss-of-diversity issues seemed apparent in the reported findings. 
Management Practices and Concerns. — Protection of colony sites of this bat at aban¬ 
doned mines through utilization of bat-compatible closure methods has been undertaken by the 
National Park Service at Guadalupe Mountains National Park (Burghardt, 2000). Numbers of these 
bats in hibemacula have not responded negatively to seasonal closures and bat-friendly gates at 
Torgac Cave on Bureau of Land Management property in New Mexico (Jagnow, 1998), and at 
Jewel Cave National Monument in South Dakota (Choate and Anderson, 1997). In an analysis of 
the effects of bat gates on multiple species, Tobin (2016) concluded that California/westem small¬ 
footed myotis (M. californicus and M. ciliolabrum not differentiated) continued using gated mines 
over the long-term, tolerated various gate designs, and that the landscape location and stmctural 
complexity of a mine were better predictors than gate characteristics of whether this species would 
continue using a site after gating. 
