O’SHEA, CRYAN & BOGAN: UNITED STATES BAT SPECIES OF CONCERN 
213 
ing temperatures and rock collapse also have been reported. Cyclones have directly impacted 
Samoan flying foxes, particularly juveniles, but carcasses were not documented. Post-cyclone 
hunting and predation on Samoan flying foxes by domestic pigs also occurred but to an unmea¬ 
sured extent, and this is the only species of concern in which hunting by humans for food has 
occurred, regardless of storm effects. Red fruit bat populations on Puerto Rico declined after a 
major hurricane, but deaths were not witnessed. Minor direct mortality of red fruit bats due to wind 
turbines has been reported, as has minor mortality of eastern small-footed myotis and big free¬ 
tailed bats, and single deaths of cave myotis and long-legged myotis. 
Disease impacts on mortality of species of concern have not been well quantified. Deaths due 
to rabies have been documented in almost all species of concern in the states, but generally not on 
the scale of mass mortality. Deaths due to white-nose syndrome have been reported in eastern 
small-footed myotis and some counts of this species have declined, but the degree of impact has 
been more difficult to ascertain than in more common species. DNA of the fungus that causes 
white-nose syndrome has been reported on Rafinesque’s big-eared bats and southeastern myotis 
(with clinical disease only in the latter), but without quantifiable mortality. Other diseases and par¬ 
asites have been documented among the various species of concern, but not in association with 
mortality. Numerous anecdotal accounts exist describing cases of predation by a wide range of 
birds, mammals, and reptiles on species of concern but without demonstration of consistent major 
impacts. Results of examinations for the presence of environmental contaminants have only been 
conducted on a small number of species of concern for some metals (California leaf-nosed bats, 
cave myotis, eastern small-footed myotis, southeastern myotis, and Yuma myotis) and organochlo- 
rine pesticides (California leaf-nosed bats, cave myotis, long-eared myotis, eastern small-footed 
myotis, and long-legged myotis). Evidence for exposure to organophosphate insecticides was 
reported for cave myotis. Lethal poisoning by environmental contaminants has not been conclu¬ 
sively demonstrated in any species of concern other than deaths of long-eared myotis and western 
small-footed myotis due to entrapment in oil sludge pits. 
The most consistently reported source of mortality has been deaths from human vandalism and 
intentional killing, primarily on accessible populations of bats roosting in caves, abandoned mines, 
or buildings. Mortality of non-volant young bats that fall beneath roosts is also known in some 
species (especially in roosts over water), although adults will often retrieve fallen young. In the 
cases where attempts were made to quantify this, neonatal mortality estimates were generally low 
(one to five percent of young in Arizona and fringed myotis, but up to 12% in southeastern myotis). 
A mysterious mass mortality event of thousands of cave myotis was reported during the 1950s, but 
multiple mortality events of unknown etiology are otherwise rarely observed among the species of 
concern. 
Population Trend: Most of the information available on population trend in the species of 
concern is anecdotal, and likely influenced by the potential bias in the studying and reporting of 
findings concerning declines and losses. Furthermore, methods for assessing status through counts 
have historically been subject to logistical and analytical shortcomings. Nonetheless, much of this 
anecdotal evidence can be compelling. Indices and qualitative assessments have indicated declines 
due to storm events for Samoan flying foxes and red fruit bats. Information on recurrence of Mex¬ 
ican long-tongued bats at historic roosting sites in Arizona and New Mexico, and spotted bats and 
Allen’s big-eared bats at netting sites in New Mexico, did not indicate population change. Historic 
locations known for greater bonneted bats in California were revisited during the 1990s and mon¬ 
itored for the distinctive echolocation calls of this species. This survey confirmed their continued 
occurrence in several regions, absence at some, and added new records. However, few colonies 
were observed directly, and all colonies were small. 
