Geology topics

Terry A. Vaughan

Publications and source records attributed to Terry A. Vaughan.

3 recordsLinked to original sources

USGS1980

Ecological observations on an East African bat community

The structure and ecology of bat faunas is a subject of interest to mammalogists (Findley, 1976; Wilson, 1973). Syntopic African bat communities, however, have received little study in comparison with neotropical faunas (cf. Fleming et al. , 1972; LaVal and Fitch, 1977; McNab, 1971). Verschuren (1957) presented natural history information and species accounts for a localized central African bat fauna. Foraging related characteristics of a Rhodesian community have also been analyzed (Fenton, 1975; Fenton et al. , 1977), but not on a seasonal basis. Other reports on African bat faunas are restricted to regional summaries (cf. Koopman, 1975 or Rosevear, 1965) and do not consider ecological aspects of a single localized community. The purpose of our study was to follow species composition, reproduction, and foraging related characteristics of an East African bat fauna over a full annual cycle.

Mammalia↗

USGS1977

Nocturnal and seasonal activities of the pallid bat, Antrozous pallidus

Nocturnal and seasonal activities of pallid bats ( Antrozous pallidus ) were observed in central Arizona. The pallid bat night is characterized by two roaming periods with an intervening period of night roosting. Foraging pallid bats have a characteristic style of flight well suited to the taking of relatively large, substrate-roving or slow flying prey. After the initial foraging period pallid bats locate one another through vocal communication and gather in night roosting clusters where they enter torpor. Durations and scheduling of nocturnal activities vary seasonally. Cool months are characterized by smaller colonies of bats, greater fidelity to certain colony sites, slower and later emergence, briefer foraging periods and longer periods of night roosting. Up to 75 percent of the time spent away from diurnal retreats is devoted to night roosting in the autumn. Young are born in June, and during most of the summer adult males do not seem to occur sympatrically with females and young. Females and young appear to forage together in July and August, when little fidelity is shown to roosting sites, large colonies exist, emergence is faster and earlier, and more time is spent in foraging than in cooler months. In mid-August a postbreeding dispersal occurs. These activities and behaviors are discussed in terms of the energetic demands on the bats and the socialization of young.

Journal of Mammalogy↗

USGS1976

Roosting ecology of the pallid bat, Antrozous pallidus

Daytime roosting behavior of pallid bats ( Antrozous pallidus ) was studied in central Arizona. Bats were present in the area from March or April until November and roosted in cliffs in colonies generally including 20 or more individuals. Pallid bats were highly selective in their choice of roost sites and minimized diurnal energy output by adaptive hypothermia and behavioral thermo-regulation. In spring and autumn the bats roosted in vertical crevices responsive to changes in ambient temperatures. Here temperatures remained low and the bats were torpid for much of the day, but when the crevices became heated in the late afternoon the bats were passively warmed prior to emergence. Deep, horizontal crevices were preferred in summer; cliffs function as massive heat sinks, and in summer crevice temperatures remained moderate and relatively stable. Throughout most of the day both the deep parts of the crevices and the body temperatures of the bats remained close to 30ºC; at this body temperature pallid bats have unexpectedly low metabolic rates (Trune, 1974). By adjusting their positions and closeness to other bats in the thermal gradient within the crevice, bats dissipate heat early in the day, maintain a low metabolic rate through most of the fat and elevate the body temperature prior to emergence in the evening. Of vital important to pallid bats in the summer are social behaviors that promote communal roosting at "traditional" crevices.

Journal of Mammalogy↗