76.

Chocolate Wattled Bat

Chalinolobus morio

French: Chalinolobe chocolat / German: Narren-Lappenfledermaus / Spanish: Calinolobo chocolate

Other common names: Chocolate Bat, Chocolate Lobe-lipped Bat

Taxonomy. Scotophilus morio J. E. Gray, 1841,

Tasmania, Australia.

This species is monotypic.

Distribution. Mostly S & E Australia, with scattered populations in WC Western Australia, S Northern Territory, N South Australia, and C Queensland; also on Fraser, Kangaroo, Flinders, and Tasmania Is.

Descriptive notes. Head-body 40-61 mm, tail 39-3-49-5 mm, ear 7-7-9-8 mm, forearm 35-42 mm; weight 5-5-13 g. Head is steeply domed with very short muzzle, often with distinct ridge of fur across muzzle between eyes. Dorsal pelage is milk-chocolate brown, ventral only slightly paler. Membranes and ears are light brownish black to blackish, and face and arms are light pinkish black. Ears are short and broad, with ribbing on inner surface, but no small fleshy lobes on lower margin close to lips (typically well developed in congeners); tragus is short, broad, and strongly curved forward, with pointed tip. Wattle at corner of lip is moderately developed, with small lobe at corner of mouth and an easily seen semicircular secondary lobe along lower lip. Uropatagium extends to end oftail, and calcar extends to almost halfway between foot and tail on uropatagium, with large, rounded postcalcareal lobe near base of foot. Skull lacks a sagittal crest; very little contrast between interorbital and intertemporal widths; supraorbital swellings present. I? has a posterior cup; I* is 40-50% height of I? above cingulum; P* is minute, and may be absent; P* has an anterointernal cusp that ranges from minute to prominent; lower molars are myotodont. Karyotype is 2n = 44.

Habitat. Rainforest, wet and dry sclerophyll forest, woodland, mallee, shrubland, and other treeless regions (e.g. Nullarbor Plain), generally close to water. In inland regions, the distribution appears to follow rivers and streams that supply the bat with large trees for roosting; it prefers more continuous forests rather than those that are patchy or fragmented. Recorded from sea level up to 1570 m in Victoria.

Food and Feeding. Chocolate Wattled Bats forage in open areas between top of understory and canopy, sometimes flying low along foresttrails. They fly fast and direct with rapid wingbeats, and gliding attack maneuvers to catch evasive prey in flight. Maximum recorded speed is 28 km /h. They forage opportunistically and diet changes with prey availability during specific times of year and in different regions; main items are moths and beetles, but they also take termites, flies, bugs, ants, lacewings, and wasps.

Breeding. Spermatogenesis occurs in males during spring and summer, and sperm is stored in the epididymis through winter, when the testes regress. The species mates mainly in autumn, but also through winter as males arouse from hibernation to mate with hibernating females. Ovulation is delayed until spring, after the females emerge from hibernation, and 1-2 young are born after gestation of 4-5 months. Births occur later in southern parts of the range than in the north, typically in October in Queensland and November in southern portions of the range. In Tasmania, births are a month later than in other bats of the region, but weaning occurs at about the same time, indicating that the lactation period is shorter. Weaning generally takes place by early February when volantjuveniles begin to appear in the population.

Activity patterns. Chocolate Wattled Bats leave their roosts at dusk to forage through the night. They hibernate in a deep torpid state through the winter, and start hibernation about a month later than other bats in their environment. This may give the species an advantage because there is no competition for food resources at this time, although food does become scarcer. Males remain more active during winter than females, as they are also mating, but both males and females arouse from hibernation to forage. Roosts are typically found in tree hollows but also in houses, under the exfoliating bark of trees, in fairy martin ( Petrochelidon ariel) nests, in culverts, under bridges, and rarely in caves (particularly in south-western areas and the Nullarbor Plain). Calls have been recorded in south Western Australia with the following parameters: lowest frequency 50-4 kHz, highest frequency 125-8 kHz, peak frequency 63 kHz, and duration 3-4 milliseconds.

Movements, Home range and Social organization. The Chocolate Wattled Bat roosts sex-specifically, female colonies usually numbering 6-70 individuals but males generally roosting alone. Colonies of up to 400 individuals have been recorded in buildings and caves. Chocolate Wattled Bats regularly switch between a number of roosts, alternating them almost daily.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Chocolate Wattled Batis widespread and does not seem to face any major threats.

Bibliography. Churchill (2008), Fullard et al. (1991), Hosken & O'Shea (2001), Kitchener & Coster (1981), Lumsden, McKenzie & Reardon (2008), Lunney et al. (1985), O'Neill & Taylor (1986), Ryan (1966), Schulz (1998a), Tidemann & Flavel (1987), Turbill (2006a), Volleth & Tidemann (1989), Young (1979), Young etal. (2008).