Habitat: Primary and secondary growth tropical rainforests, gallery forests, mangroves or paperbark forests

Australian distribution: Wet Tropics from Cooktown to Ingham, and in smaller numbers from Coastal Queensland from Tully to the tip of Cape York 

Conservation status: Endangered - originally listed as vulnerable under National Environmental Law (Environment Protection and Biodiversity Conservation Act 1999) in 2002, a major heatwave in 2019 wiped out one third of the Australian population, and resulted in this species being listed as endangered. 

Main threats: 

  • Environmental threats: cyclones, tick paralysis, competition, temperature-related stresses and diseases such as cleft palate syndrome
  • Human threats: habitat loss, grazing and urban development, man-made obstacles (barbed wire fences and powerlines) and human harassment

Predators: Carpet python, white-breasted sea eagle and occasionally crocodiles

About 

Spectacled flying-foxes (Pteropus conspicillatus) are large fruit bats, famous for the straw-coloured fur around their eyes and across the back of their neck and shoulders, which gives them their name.

This species is sexually dimorphic in size. The females can weigh 510-665g, while the males weigh 950-100g. Their forearm length is 157-181mm and their head-to-body length is 220-240mm.

Little is known about the life span of spectacled flying-foxes in the wild, but they can live in captivity for 17 years.

Did you know? Electric grids were used by fruit-growers to kill feeding flying-foxes in Far North Queensland. It was a major threat to the species in the early 21st century, until a series of court cases by conservationists set a legal precedent and resulted in electric grids being banned in Queensland.

Diet

Spectacled flying-foxes are specialist fruit-eaters that feed mostly on rainforest fruits. They also appear to favour nectar and pollen of eucalypt blossoms.

They provide pollination and disperse seeds to at least 26 species of rainforest canopy trees. Salt is also an important part of their diet, obtained by skimming over the surface of salt water to drink or chewing mangrove leaves. This is a risky manoeuvre in FNQ waterways which are often home to estuarine crocodiles. 

Behaviours 

P. conspicillatus forages only at night, leaving roosting sites to congregate on fruiting trees. They are territorial and aggressive with rich food resources. Those who arrive early in the evening, called 'residents', will establish feeding territories, and quickly force out individuals who arrive later as 'raiders'. This 'raiders vs. residents' model of nocturnal territorial behaviour causes the long-distance dispersal of fruits.

Mating is common in the early part of the year, with conception peaking from March to May. During breeding, the males put on a lot of weight and defend their territory. They mark their territory with secretions from their scapular glands, and an oily red secretion is usually clearly seen around the neck. 

Following a 7-month gestation period, mothers give birth upside down - usually to one baby - between October and December. If the female does bear a baby, males and females form a monogamous bond. If not, the males are polygynous.

Soon after mating, the colonies break into smaller groups close to food resources for winter, but return to larger colonies in spring ready for birthing.

When the pup is born it cannot maintain its body temperature and must remain on the mother all the time, hanging on as she flies out at night to feed. By about 6 weeks of age, the pup is too heavy to fly with the mother and is left in a creche in the roost with other pups. From here, they become very active at night, eventually taking short flights by 12 weeks of age. 

They are fully dependent on their mother’s milk until they gain strength for longer flights to feed on fruit and nectar. They are fully weaned at 5-6 months of age.

Having a connected rainforest is crucial to the long-term survival of this species. You can help protect spectacled flying-fox habitat in the Daintree. Find out how.

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  • Mark Bihag
    published this page in Canopy Library 2024-04-02 12:03:44 +1100