O’SHEA, CRYAN & BOGAN: UNITED STATES BAT SPECIES OF CONCERN 
169 
were colonies of other species of Myotis. Disturbance and banding studies also have been associ¬ 
ated with large declines in populations at hibemacula in northwestern Texas (Tinkle and Patterson, 
1965). 
A hibernating colony averaging over 1,500 of these bats at Torgac Cave on the Roswell 
Resource Area of the Bureau of Land Management in New Mexico responded favorably to sea¬ 
sonal closures against people and bat-friendly gates (Jagnow, 1998). Protection of colony sites at 
abandoned mines through utilization of gates or other bat-compatible closure methods has been 
undertaken by the National Park Service at Big Bend National Park, Guadalupe Mountains Nation¬ 
al Park, and near the Fort Bowie National Historic Site (Burghardt, 2000). One colony site on the 
Fort Huachuca Military Reservation in Arizona that was previously abandoned by this species 
increased to over 8,000 bats following installation of protective fencing and a security system 
(Buecher and Buecher, 2002). Despite such accounts, it also has been suggested that in some areas 
very large colonies of cave myotis may not readily accept gating of mines (Brown, 2013). In an 
analysis of the effects of bat gates on multiple species, Tobin (2016) concluded that cave myotis 
continued using gated mines over the long-term, tolerated various non-culvert gate designs, and 
that the landscape location and structural complexity of a mine were better predictors than gate 
characteristics of whether this species would continue using a site after gating. Evidence also indi¬ 
cated that colonies of cave myotis respond more negatively to culvert gates than other mine-roost- 
ing species of concern that have been studied (Tobin, 2016). 
Mann et al. (2002) investigated the potential impact of guided public tours on a maternity 
colony of cave myotis at Kartchner Caverns State Park in Arizona. They quantified behavior of bats 
indicative of disturbance (vocalizations, activity levels in clusters, landings and fallings) in relation 
to experimental tour group size, presence of talking, and four levels of light intensity and color. 
Talking and higher intensity white light produced more disturbance than no talking or lights, with 
red light and dim white lights having intermediate impacts. Bats also showed greater disturbance 
when tour groups were closer, and disturbance levels increased as the maternity season progressed. 
Mann et al. (2002) recommended that no tours be allowed during the maternity season, that efforts 
be made to minimize disturbance during other times, and that use of the cave by this species be 
carefully monitored. 
Notes and Comments.— Kunz (1974) estimated that the population of cave myotis in 
Kansas alone consumed 16 tons of insects in a single year. These bats tend to emerge early, well 
before dark, in large numbers but at a slow rate. Females have been observed to retrieve fallen 
infants from below roosts (Kunz, 1973). 
Myotis volans — Long-legged myotis (Family Vespertilionidae) 
Conservation Status. — National and International Designations: U.S. Fish and Wildlife 
Service (1994, 1996a,b): Species of Concern (inactive, former Category 2 candidate for listing 
under the U.S. Endangered Species Act). U.S. Forest Service (2005a,b): Sensitive Species. Bureau 
of Land Management (2009a, 2011b, 2015b): Sensitive Species (Idaho, Montana, Nevada, North 
Dakota, South Dakota state offices). International Union for the Conservation of Nature (2017): 
Least Concern. NatureServe (2017): Global Ranking G4 - Apparently Secure. 
State Designations: Alaska Department of Fish and Game (2005, 2015): Species of Greatest 
Conservation Need. California Department of Fish and Wildlife (2015b, 2017): Special Animals 
List, Species of Special Concern. Nebraska Game and Parks Commission (2011): At-Risk Species 
Tier II. North Dakota Game and Fish (Hagen et al., 2005; Dyke et al., 2015): Species of Conser¬ 
vation Priority Level III. Oregon Department of Fish and Wildlife (2005, 2008): Sensitive Species, 
Vulnerable. Texas Parks and Wildlife (2012): Species of Greatest Conservation Need. Washington 
Department of Fish and Wildlife (2015a): Species of Concern. Wyoming Game and Fish Depart- 
