73.

Hoary Wattled Bat

Chalinolobus nigrogriseus

French: Chalinolobe cendré / German: Schwarzgraue Lappenfledermaus / Spanish: Calinolobo cenizo

Other common names: Eastern Wattled Bat, Hoary Bat, Pied Bat; Blackish-gray Bat (nigrogriseus), Frosted Bat (rogersi)

Taxonomy. Scotophilus nigrogriseus Gould, 1852,

vicinity of Moreton Bay, Queensland, Australia.

Two subspecies are recognized.

Subspecies and Distribution.

C.n.wnigrogriseusGould,1352-SENewGuinea(includingFergussoninD’EntrecasteauxIs)andNEAustralia,fromCapeYorktotheClarenceRiverinNENewSouthWales(includingFraserandStradbrokeIs).

C. n. rogersi Thomas, 1909 — N Australia in NE Western Australia, N Northern Territory, and NW Queensland, including Tiwi and Groote Eylandt Is.

Descriptive notes. Head-body 39-6-58-2 mm,tail 26-43 mm, ear 7-5-13 mm, hindfoot 6-9-8-9 mm, forearm 31-6-39-4 mm; weight 4-2-10 g. Dorsal pelage is dark gray to black, and ventral pelage is grayish brown; fur is frosted with white tips both dorsally and ventrally, giving a hoary appearance, although some individuals lack white frosting, and Western Australian populations have more frosting than Queensland populations; there is some lighter grayish, light brown, or white hair on the ventral margins of the membranes, and light hairs that extend onto the venter of the wing and uropatagium, rarely having a distinctly white Vsshaped band similar to the Little Pied Bat ( C. picatus). Membranes and ears are black, and some parts of the face and the arms are dark pinkish brown to black. Ears are short and broad with ribbing on inner surface and small fleshy lobes on lower margin close to lips extending under eyes; tragus is pointed inward, rounded, and stubby. There is a fleshy lobe at the corner of the mouth thatis very poorly developed compared to other congeners. Uropatagium extends to end oftail. Skull has well-developed supraorbital swellings; braincase is large and has a low sagittal crest; much contrast between interorbital and intertemporal widths; rostrum is low and swollen. No posterior cusp on I% I? is about one-third height of I* above cingulum; I’ has a notch (unlike the Little Pied Bat); there is a weakly to well-developed anterointernal cusp on P* P? is minute, or even missing in some cases; lower molars are myotodont.

Habitat. A variety of habitats, including monsoon forests, tall open forests, open woodlands, dry sclerophyll forests ( Eucalyptus camaldulensis, Myrtaceae), riparian woodlands, littoral rainforest, deciduous vine thickets, coastal scrub, sand dunes, spinifex-covered hills, grasslands, and floodplains. Commonest in lowlands, from sea level up to 300 m.

Food and Feeding. Hoary Wattled Bats forage close to water and in swampy areas, and have been seen foraging along the forest edge, above the canopy, and close to rivers and creeks in forest, generally avoiding dense vegetation away from water. They catch prey both aerially and by gleaning off the ground and foliage. They are moderately fast fliers, reaching speeds up to 34 km /h; they frequently change direction quickly to catch evasive prey, which they can detect 3-5 m away. They have a varied insectivorous diet, but prefer beetles, ants, and moths; also recorded are spiders, mantises, earwigs, crickets, grasshoppers, cockroaches, cicadas, bugs, flies, and lacewings.

Breeding. Pregnant females have been recorded in July, August, October, and late November. Twins (rarely single young) are born during October and November and lactating females have been observed from October through January.

Activity patterns. Hoary Wattled Bats leave their roosts to forage early in the evening (often before other bats have emerged), and have been observed foraging at twilight, often emerging in large numbers at the same time. They roost in hollows in trees and in roofs of buildings, occasionally also in rock crevices. Call shape is FM/QCF with a characteristic frequency greater than 36 kHz (36-1-40-8 kHz).

Movements, Home range and Social organization. The Hoary Wattled Bat roosts in colonies of up to several hundred individuals. In New Guinea, a maternity colony was reported with several hundred females and their young in the roof of a building in November. In this maternity colony, bats clustered in groups of 10-40, some solitary, but no males were present.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Hoary Wattled Bat is widespread and common throughout its range, and does not seem to face any major threats. Roost disturbance and loss may be locally significant.

Bibliography. Bonaccorso (1998), Churchill (2008), Flannery (1995a, 1995b), Hutson, Schlitter, Csorba, Thomson & McKenzie (2008), Kutt et al. (2008), McKenzie, Fontanini et al. (1995), Milledge et al. (1992), Milne (2002), Ryan (1966), Van Deusen & Koopman (1971), Vestjens & Hall (1977).