Project Description

Black flying fox (Pteropus alecto)

A widespread largely coastal flying fox that occurred across northern Australia but only south of the Queensland border until about the late 1990s. They gradually extended their range as far south as Sydney in 2006, increasing their susceptibility to heat stress events. Individual Black flying foxes have been reported in Melbourne and Adelaide, but no camps.

Black flying foxes are a little bit different.

They are the only Australian flying fox with variable birthing times. In the Northern Territory pups are born January to March, but further south on the east coast they are mostly born in October/November. A small proportion are also born outside these peak birthing months. They seem to be able to get pregnant again, more or less immediately, if they lose a pup. This variability in birthing times is virtually unknown in the other three mainland Australian flying fox species.

In the Extreme mobility study Black flying foxes were noted to be less mobile than the other two flying fox species studied, the Little Reds and the Grey-headeds. In Hendra virus studies they also appear to be more associated with spillover events than these two species.

Another unusual feature of Black flying foxes is reports of them roosting in limestone tower at Chillagoe, and in a water-worn limestone tunnel at Tunnel Creek National Park (Dimalurru) in Western Australia. In both instances it is most likely to escape the heat.

Black flying fox records from Atlas of Living Australia

Black flying fox records from Atlas of Living Australia

Black flying foxes in a limestone cave at Tunnel Creek

(photo above) Black flying foxes at Dimalurru , (photo right) Black flying fox mother with pup, note the typical reddish brown mantle on the back of the pup.

Mother and pup Black flying fox

The main threats faced by Black flying foxes include:

In January 2014, an estimated 46,000 Black flying foxes died in 52 camps during an extreme heat stress event in south-east Queensland. This is by far the largest heat stress event in recent Australian history.

PTEROPUS ALECTO

DESCRIPTION

A large black flying fox with a reddish brown mantle on the back of the neck. Sometimes white-tipped hairs not he belly and faint red-brown eye rings.

DISTRIBUTION & HABITAT

Black flying foxes are the least mobile of the 3 Australian flying fox species studied in the Extreme mobility paper, the average of those collared travelling 1427–1887 km a year. The estimated daily turnover rate of individuals was 11.9 ± 1.3%. They roost in a wide range of habitats often hanging higher than the Grey-headed flying foxes in their shared camps but also as low as 2 metres in mangroves in northern Australia.

DIET

The  primary food source in Australia is the flowers of Eucalyptus, Banksia, Melaleuca species, plus rainforest and exotic fruits.

MATING SEASON

As discussed earlier they are the only Australian flying fox with variable birthing times (see introductory text above). For those on the eastern Australian coast, mating occurs in the early part of the year with conception peaking March to April. As with the other Australian flying fox species, the males put on a lot of weight at this time of year and defend their territory. They try to leave their branch/es only for short periods to feed. Males mark their territory with secretions from their scapular glands.

BIRTHING SEASON

The variability in birthing times means the Northern Territory pups are born January to March, but on the east coast mostly  in October/November. Bat carers report that Black flying fox pups are increasingly coming into care being born out of season.

LIFE HISTORY OF THE PUP UP TO JUVENILE AGE

When the pup is born it cannot maintain its own body temperature and must remain on mum all the time, hanging on as she flies out at night to feed. The claws bed into her fur and the mouth is firmly on the nipple. By about 6 weeks of age the pup is too heavy to fly with and it is left in a creche in the roost with other pups. Here they become very active at night doing a lot of flapping and eventually short flights by 12 weeks of age. We have had mothers caught on barbed wire fences with pups up to 250 gms so it’s not that they can’t fly with the bigger pups, but it is hard work. Until now they have been completely dependent on their mother’s milk. As they gain strength for longer flights they learn to feed on suit and nectar, until they are fully weaned at 5-6 months age. They tend to hang with their own age group before fully joining the adult like of the camp in their third year.

POPULATION

The wide distribution of Black flying foxes in Australia means there is no reliable means of estimating population, but a decrease of population in NSW has been reported.

CONSERVATION

See internal links Flying Fox Conservation

MORE INFORMATION

Churchill, Sue (2008) Australian Bats. Out of print, soon to be superseded by an expanded digital version
Hall, Les & Richards, Greg (2000) Flying Foxes, Fruit and Blossom Bats of Australia
IUCN Red List
Extreme mobility paper