European Free-tailed Bat
Morphological description Life history Distribution Habitat Roost sites and roosting patterns Emergence and flight pattern Foraging behaviour Echolocation calls Status and protection
East Asian bats are sometimes considered as a distict species, Tadarida insignis (Yoshiyuki 1989), although the T. teniotis species group is poorly understood and in need of systematic revision (Smith & Xie 2009).
· Dorsal fur is black-grey. Ventral fur is grey or white-grey.
· Juveniles are greyer than adults.
· A relatively large species of Tadarida. Forearm length of bats captured in Yunnan ranged from 60.2-64.7mm (n = 6).
· Ears long and broad and project forwards beyond eyes and face. Base of ears touches at front.
· Wings very narrow and long.
· A free tail extends beyond the tail membrane for one-third to half of its length.
· A smooth pad is present on the sole of the foot, and also occurs at the base of the thumb.
· Weights of bats captured in Yunnan during early September ranged from 30.5-38.5g (n = 6).
· Little known.
Widespread: found also in southern Europe. Recorded also from Afghanistan, north east India, north east Thailand, north Ryukya Islands, Korea, Japan and North Africa (Corbet & Hill 1992). The Chinese distribution is shown by dots on the map (as given by Zhang et al. (1997).
· In Portugal fed preferentially over forested areas and used alluvial plains and valleys of a mountainous area, but not the mountain ridges (Marques et al. 2004).
· Found in caves in Yunnan. Roost contained bats of both sexes. Roosts in crevices cliff faces in Europe, also in buildings (Arlettaz 1990; Schober & Grimmberger 1989). Can use torpor at low temperatures (Arlettaz et al. 2000).
· Narrow wings and a high wing loading and aspect ratio mean that this species flies rapidly and is not very manoeuvrable. In Portugal leaves roost about one hour after sunset, and had only one foraging bout lasting up to 6 hours. Forages high above the canopy. May fly at over 50 km/h (Marques et al. 2004).
· In Portugal flies to a feeding site averaging 100 ha which may be shared with other bats. Colony range was over 30 km in radius, but most feeding sites were 5 km from the roost (Marques et al. 2004). In Europe feeds on tympanate insects such as moths and lacewings (Rydell & Arlettaz 1994).
. This species emits long (ca. 20 ms) signals of limited bandwidth that are audible to unaided ears, with frequencies between 18-10 kHz in Europe. Russo & Jones (2002) recorded a mean start frequency of 17 kHz, and end frequency of 12.1 kHz, and a frequency of most energy at 13 kHz. Pulse duration averaged 16.6 ms and pulse interval was 622 ms. these data were from Italian bats. Spectrogram below based on a figure in Russo & Jones (2002) (gap betwen pulses not to scale).
· There is no estimation of population size for China.
· European free-tailed bats are widespread and probably not endangered on a global scale. Listed at LR/lc, assessed by the Red List of Threatened Species (IUCN, 2006) and not protected by the Law of the People's Republic of China on the Protection of Wildlife in 1989.
· Caves should be protected as their habitats.