O’SHEA, CRYAN & BOGAN: UNITED STATES BAT SPECIES OF CONCERN 
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live oak hillsides, xeric scrubland, and near riparian vegetation as well as in ponderosa pine habi¬ 
tats of the Sierra Nevada in California (for example, Vaughan, 1959; Pierson and Rainey, 1998c). 
Acoustic surveys in mountain ranges in California suggest that these bats shift seasonal distribu¬ 
tions down drainages to lower elevations in winter (Pierson and Rainey, 1998c). 
Despite being a fast-flying bat with relatively low maneuverability, this species is not usually 
captured over water during extensive mist-netting surveys of bat faunas within its known range, 
indicating a patchy distribution (for example, Cockrum et al., 1996; Pierson et al., 1996b). How¬ 
ever, it was the fourth most common species (83 among 1,052 bats of 15 species) taken over water 
at one site in Big Bend National Park in Texas during 1967-1971, where it was captured at only 
three sites out of 32 netting locations; all three sites were in river floodplain and shrub desert habi¬ 
tats below 1,220 meters elevation (Easterla, 1973). In a subsequent study during 1996-1998, it 
ranked sixth in abundance at Big Bend National Park overall (88 among 1,978 bats of 17 species), 
where it was taken at only three sites, all in lowland habitats on the river flood plain (Higginboth¬ 
am and Ammerman, 2002). The greater bonneted bat ranked sixth of 17 species (18 individuals 
among 390 bats) captured in mist nets at 19 sites in the Sierra Nevada mountain range of Califor¬ 
nia during 1993-1999 (Pierson et al., 2001). 
Eight lactating females were captured over water in meadows in ponderosa pine and Douglas 
fir forests at elevations of 2,400-2,650 meters on the Kaibab Plateau of northern Arizona in 1995; 
ten other individuals were also captured in the same habitat over the next two years, ranking fifth 
in relative abundance out of 96 captures of nine species (Siders et al., 1999; Melissa S. Siders, 
Bureau of Land Management, written commun., 2017). They ranked fifteenth in abundance among 
17 species of bats (three captured of 1,171 total bats netted) taken over water mostly in ponderosa 
pine and pinon-juniper habitats of the Arizona Strip in northwestern Arizona (Herder, 1998). 
Foraging and Dietary Analysis. — This bat has a wing morphology adapted for rapid, 
long-distance flight, especially in open areas. The short velvet-like pelage may be an adaptation to 
reduce drag during flight. It is apparently the fastest flying of the U.S. molossid bats (Vaughan, 
1966). Flight behavior of the greater bonneted bat was reported by Vaughan (1959). They typical¬ 
ly emerge late into evening darkness, uttering loud, shrill calls and smacking sounds prior to and 
upon emergence. Bats often emerge singly at irregular intervals over periods of up to two hours. 
Steep dives of some 3 to 6 meters may be made before individuals pull upward and engage in level 
flight. Bats in flight make single-note high-pitched chirps every two to three seconds. They may 
fly at great heights. Vaughan (1959) observed bats flying to heights of 300 meters before being lost 
from view, and based on faintness of cries suggested that elevations as high as 900 meters above 
ground were obtained, although in other instances they were observed flying 30 to 60 meters above 
ground and water. They may fly great distances, and observations in southern California support 
the idea that weather in coastal regions may influence bats to forage in the interior over the Mojave 
Desert on any given night (Vaughan, 1959). Bats sometimes return to colony sites and make repeat¬ 
ed dives at the entrance during the middle of the night. Much remains to be learned about the feed¬ 
ing ecology of this species, but in some areas this species appears to favor feeding over open areas, 
meadows, and reservoirs (Pierson and Rainey, 1998c; Siders et al., 1999). 
Morphological specializations of the head and limited information on food habits suggest that 
this species feeds primarily on moths (Freeman, 1979). However, items reported from analysis of 
43 fecal pellets and stomach contents of four bats from Arizona were primarily small (eight mil¬ 
limeters in length) insects, mostly hymenopterans but also including beetles, moths, and dragon¬ 
flies (Ross, 1961). The large number of small-bodied insects reported from western Arizona is con¬ 
sistent with Vaughan’s (1959) hypothesis that in southern California these bats will feed on small, 
light insects carried high aloft by warm updrafts. Nonetheless, further analysis of gastrointestinal 
