74.

Gould’s Wattled Bat

Chalinolobus gouldii

French: Chalinolobe de Gould / German: Gould-Lappenfledermaus / Spanish: Calinolobo de Gould

Taxonomy. Sotophilus gouldii J. E. Gray, 1841,

Launceston, Tasmania, Australia.

Chalinolobus gouldii previously included C. neocaledonicus, but they are now considered separate species, based on morphological data; however, further investigation at the genetic level is needed to confirm this. The Norfolk Island population probably represented a distinct subspecies, if not species. A race venatoris has sometimes been recognized in northern Australia, but its validity is uncertain. Treated as monotypic, pending further studies.

Distribution. Most of mainland Australia, with the exception of Cape York and Nullarbor Plain; also Koolan, Tiwi, Kangaroo, King, and Tasmania Is, and old records from Norfolk I. There is also a record of a female captured in November 2010 from Lord Howe I, although this was probably a vagrant.

Descriptive notes. Head-body 46-75 mm,tail 40-50 mm, ear 7-2-13-3 mm, forearm 37-48 mm; weight 8-18 g. Gould’s Wattled Batis strikingly colored and largest species of wattled bat, being larger in the south than in the north. Muzzle is short with well-developed nasal glands on either side, and face is short and flat. Fur is fine, long, and velvety; dorsal pelage grades from dark blackish brown on head and shoulders to brown along the back, becoming much lighter near uropatagium, where fur extends onto part of the membrane, often slightly reddish near head and yellowish toward uropatagium; ventral pelage generally slightly lighter overall, and shows similar gradation, becoming lightest toward wings and uropatagium; bats tend to be darker, more blackish in northern part of range, becoming lighter and more prominently brown in south. Membranes are dark brown, almost purplish, and ears, face, and digits are likewise dark brown. Ears are short and broad, with ribbing on the inner surface and with small fleshy lobes on lower margin close to lips; tragus is pointed inward, rounded, and stubby. Fleshy lobe at corner of mouth is well developed and extends onto lower lip. Uropatagium extends to tip oftail. Skull has large braincase; rostrum is broad and low; sagittal crest very weakly developed. P? is very small; lower molars are myotodont.

Habitat. Nearly every habitat type—from rainforests, eucalypt forests, woodlands, alpine regions, grasslands, deserts, agricultural regions, and urban areas—throughout Australia, at elevations from sea level to at least 1500 m.

Food and Feeding. Gould’s Wattled Bat is a maneuverable flier that is faster than most vespertilionids at up to 36 km /h. It often flies on a fixed horizontal plane with abrupt zigzags, and will frequently roll to bank near vertically during horizontal turns. When foraging,it flies just below or within the lower level of the canopy and along forest edges and creek lines. It usually forages 5-10 km from its day roost, occasionally up to 15 km away. It feeds aerially. Diet insectivorous but varies greatly from region to region, mainly consisting of true bugs and moths, but ants (winged and wingless), cockroaches, stoneflies, katydids, field crickets, cicadas, beetles, flies, and caterpillars have all been reported in the numerous fecal and stomach samples studied.

Breeding. There is one breeding season per year, with copulation occurring in May to June but sometimes as late as August. There are peaks in testicular enlargementin February in Western Australia and Victoria. Females store sperm in their uterine lining over winter, delaying ovulation and fertilization until the end of winter. A vaginal plug is also created after copulation. Gestation lasts ¢.3 months. Litter size is usually two (one in each uterine horn) but occasionally only one. Reproductive and parturition timing change by latitude, births being later in southern regions: births occur in late September in north, but in October in central regions, and in late November in south. Young reach adult size and are volant and independent by c.5 weeks. In western Victoria, females can breed in theirfirst year but do not breed every year, with only 70-80% of females breeding in any one year.

Activity patterns. Gould’s Wattled Bats are nocturnal, and often leave their day roosts early (c.20 minutes) after sunset, when there is still a good amount of ambientlight, making them vulnerable to predation. They are the first bats to begin foraging in some regions, such as South Australia. During colder parts of year, in cooler and more southerly portions of the range, they hibernate. They will spontaneously arouse from hibernation at temperatures of 5-25°C to forage; males may also arouse to mate with hibernating females. They also enter torpor during the day, which reduces energy and evaporative water loss. Day roosts are most commonly found in tree hollows and the hollow limbs of mature living trees, particularly in river red gums ( Eucalyptus camaldulensis, Myrtaceae) and cypress pines (Callistris sp., Cupressaceae); they have also been noted in buildings and tree stumps, among leaves,in a roll of canvas, and strangely in the exhaust pipe of a tractor. Call shape is a steep FM/QCF sweep. In south-western Australia, the following call parameters were recorded: average maximum frequency 106-1 kHz, minimum frequency 29-6 kHz, peak frequency 41-3 kHz, and call duration 2-7 milliseconds.

Movements, Home range and Social organization. Gould’s Wattled Bats have been reported sharing tree-hollow roosts with several other bat species and feather-tailed gliders (Acrobates sp.). Males and females roost separately during breeding; females roost in colonies generally of 8—40 bats but of as many as 80 in buildings; males usually roost solitarily. Outside breeding season, mixed colonies can form, and up to 200 individuals have been reported, although malesstill tend to roost solitarily. They usually change roosts often, generally daily and within 300 m of other roosts. Day roosts will be reused often from year to year, and one tree hollow was reported to be occupied for at least six years. Young seem to remain at the maternity roost for less than a year, and females appear to be more loyal to specific roosts than males.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Gould’s Wattled Bat is very widespread and common throughout its range, with no major threats currently identified. Not recently recorded on Norfolk Island, where probably extinct.

Bibliography. Churchill (2008), Chruszcz & Barclay (2002a), Dixon & Huxley (1989), Dixon & Lumsden (2008), Eldridge et al. (2017), Flannery (1995a), Godinho et al. (2015), Hosken & Withers (1997), Kitchener (1975), Lumsden & McKenzie (2008), Lumsden et al. (2002a), O'Neill & Taylor (1986, 1989), Reinhold, Herr et al. (2001), Tidemann (1986), Vestjens & Hall (1977), Young (1980).