Sometimes, whilst cycling or walking along a pathway, usually near a waterway, an unusual noise will grab your attention.
Looking up, the realisation that hundreds of cute little faces emerging from tightly wrapped wings that appear to tuck them in, as we snuggle into our doonas – are watching every move you make. One gets a sense that the chatter could well be about the intruder !! . . .
Their likeness to a dog’s face, with their big eyes and cute little ears, immediately draws you in. Remarkably, they are the only mammals capable of sustained flight – an amazing achievement when one considers that some species can reach up on 1 kg in weight, with a wingspan of up to 1 metre !!!
Their large eyes are highly adapted for day and night vision and tuned into recognising colours at night – essential in their search for food and for navigation. They do not echolocate and therefore rely on their sight to navigate – via rivers, landmarks, and so forth.
Flying Foxes are vital to the pollination and seed dispersal of many Australian plants including native hardwoods and rainforests. Many rainforest trees have evolved to produce pale-coloured fruit on their outer branches, thereby making them more visible to the Flying Foxes at night. Many seeds have adapted to not germinate unless they are some distance from the parent tree. As Flying Foxes forage for food, they will often carry the fruit for some distance, eat and spit out the seeds – other times they will eat it on the spot, swallow the seeds and pass them in their faeces at a later time and at whatever location they may find themselves. It is estimated that a single Flying Fox can disperse up to 60,000 seeds in just one night !!!
Evenings – thousands take flight in search for Food …
Flying Foxes rest by day and feed by night.
To rest, they set up camps – whether they be temporary or permanent – and roost by hanging upside down, folding their wings around or beside them, often beside a creek or watercourse in tall, reasonably dense vegetation areas such as gullies, lowland rainforests, coastal stringybark forests and mangrove forests. Interestingly, the anatomy of a Flying Fox is very similar to ours – the possibility that they are related to primates has not yet been ruled out . . . Anatomical modifications such as the relocation of the hip socket, and, the acetabulum of the hip upward and rearward – enables the Flying Fox to hanging from a branches for hours on end. This, coupled with the large claws on their feet, and a tendon-ratchet system that ‘locks on’ – allows them to hang without straining their muscles. Their hands are structurally the same as ours, however their digits are proportionally longer. They do not have a tail, and claws are present on their first and second digits.
Camps are also vital for their young. Flying Foxes face many challenges and their replenishment rate is slow. Males take some 30 months to reach sexual maturity – a ripe old age considering the average life span in the wild is just four years . . . Top this with high rates of infant mortality and that only one infant is born to a female during a 1 year period. Flying-foxes are placental mammals, giving birth to live young. The baby clings to the mother’s belly for the first 3 weeks until it becomes too heavy to carry. At 3 weeks of age, the young are left at a crèche in the centre of the camp during the night, whilst the mothers fly out to feed. Mothers return just before dawn and recognise their young, by their smell.
Around dusk each evening, adults and adolescents leave the camp to search for food. The timing of departure appears to be influenced by availability of food. Should food be short supply or a long distance away, they will leave before sundown. When food is plentiful or nearby, or when there is a full moon, they will leave well after dark. They prefer blossom, nectar, fruit and occasionally leaves of native plants, particularly eucalypts, tea-trees, grevilleas, figs and lilly pillys.
Flying-foxes are very vocal. They use their voices to communicate about feeding and camp sites with more than 30 different calls being recorded from the Grey-Headed Flying Fox. The various calls are associated with specific behaviours such as mating, finding their young in the camp, territorial disputes over food . . .
Flying Foxes are nomadic mammals, found throughout tropical and sub-tropical Asia, Australia, and the islands of the Indian and western Pacific Oceans. Their movement patterns are determined by variations in climate. availability of food, flowering and fruiting patterns, and availability of camp sites.
The preconceptions that Flying Foxes carry disease is quite disproportionate. A very small number of Flying Foxes may carry the ‘lyssavirus’, a virus that is likened to the ‘rabies’ virus and potentially fatal to humans, however, this virus is transmitted only via saliva and must be transmitted via a bite or scratch from an infected animal. People will not be exposed to the lyssavirus when the Flying Foxes are flying overhead, whilst they are roosting or feeding in garden trees, or even from touching their droppings.
Mankind is the greatest threat to the Flying Fox, as deforestation continues – their traditional camps are destroyed and their food sources depleted. Farmers actively shoot and poison them – culling the Flying Foxes who are forced to resort to cultivated crops when their traditional foods have destroyed. Obstacles such as power lines and barb wire fences claim many, many lives . . . Since the arrival of the European some 200 years ago, the decline in numbers of Flying Foxes is so great that some species are now classified as vulnerable.
Natural predators are pythons, sea eagles, kites, crows, owls, dingoes, domestic dogs, foxes, and in the northern regions, crocodiles are known to wait, submerged, to snatch a Flying Fox as it swoops to drink. They have also been seen to use their tail to dislodge the Flying Foxes whilst they are roost in mangroves . . .
Classification of Flying Foxes:
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There are four species native to mainland Australia:
→ Grey-Headed Flying Fox
(Pteropus poliocephalus)
The Grey-Headed Flying Fox is prolific within 150 km of the sea, on the eastern coast of Australia – all the way from the Hervey Bay region in Queensland, to Melbourne in Victoria. They can be found in various habitats such as coastal rainforests, woodlands, wetlands, and swamps; and, tend to migrate to where their food supply is more abundant, but always returning to their ‘home’ camps.
They roost in the branches of large trees and are very social. Flying Foxes have very small leg muscles to keep their bodies as light as possible to be able to fly. Their small legs are unable to support their weight, therefore they have adapted to roost or rest by hanging upside down.
Their camps can house up to several thousand – especially during mating season. The Grey-Headed Flying Fox exhibits a sophisticated array of vocalisations, comprising of a series of squeaks and squeals. Some 30 different calls have been identified. Their camps are usually found in gullies close to a watercourse, which they return to the same camp year after year . . .
They rest by day, and feed by night.
They can fly up to 50 km to find food. Their diet consists of fruits, pollen, nectar, and bark. Their favourite is eucalyptus blossom: gummifera, muellerana, globoidea and botryoides. One of their favourite fruits is fig, and they are know to eat the leaves of the poplar and grey mangrove. They are vital for the seed dispersal and pollination of many plant species and if it were not for the Grey-Headed Flying Fox, these plants could not spread further afield. Reducing numbers of these animals could well have a huge negative impacts on the regeneration of Australia’s forests.
The Grey-Headed Flying Fox is the largest of the bat species in Australia. Their bodies and heads are grey in colour, but it is the beautiful neck collar of reddish-brown fur that makes them distinctive, as well as the fact that their fur extends all the way to their ankles. Their wingspan can be up to 1 m, weighing in at between 600 g to 1 kg. They generally live between 2 to 5 years in the wild, however, in captivity this can extend up to 15 years !!
They generally mate between the months of April to May and give birth to a single baby between October and November. The gestation period is some 6 months and the young are weaned at between 5 and 6 months of age. Interestingly, during the nursing period, males and females form monogamous mating-pairs. The males do not directly care for the young, however, they are there to defend and protect should trouble arise. The mothers carry their young for the first 4 to 5 weeks of life, even whilst foraging for food. For the next 3 months or so of an infant’s life, they are left at camp whilst the mother searches for food. Grey-Headed Flying Foxes must achieve at least 90% of their adult wingspan and 70% of their adult body mass, before they can sustain flight and hence are not weaned until the milestone is reached.
They achieve sexual maturity at approximately 1½ years of age.
Once again, the main threat to the Grey-Headed Flying Fox is man. Destruction of their habitat through deforestation, loss of food sources, shooting by farmers, power lines are just some of the obstacles caused by humans that threaten this species. The numbers are declining so rapidly that they are listed as vulnerable in some areas of Australia, however, in others they do not even rate a mention, possibly so that the farmers can continue culling the ‘nuisance’ ??? . . .
→ Spectacled Flying Fox
(Pteropus conspicillatus)
The unusual common name has been applied due to the yellow-green to light brown rings around the eyes of the Spectacled Flying Fox, which literally resembles spectacles !!! Their territory is the most restrictive of all the flying foxes in Australia, being in a small region in north-east Queensland, above latitude 19º S – possible due to the fact that they absorb heat from their surroundings ? . . . Outside Australia they are found in the Halmahera Islands, New Guinea, and some adjacent islands. The Spectacled Flying Fox is found in both primary and secondary growth tropical rainforests – roosting in dead trees or trees stripped of their foliage. They have been recorded as living for up to 17 years in captivity.
Females are somewhat smaller that their male counterparts, weighing in at approximately 510 – 665 g. Males weigh between 950 g – 1 kg.
The Spectacled Flying Fox rests or roosts by day and feed by night.
Colonies of the northern most regions will migrate southward during the wet season when food is scarce. 90% of their diet consists of light coloured fruits of forest trees and palms. The Spectacled Flying Foxes locate their food visually and therefore are attracted by light coloured fruits that stand out again the dark forest canopies in the night time. Their eating habits are very much ‘first in, first served’ whereby late arrivals are forced to find other fruit trees. Fruits eaten by the Spectacled Flying Fox include citrus, mango, Northern Bloomwood, Apple Box, and, they are often regular visitors to orchards . . . They are an important disperser of rainforest plants, many of which have adapted to attracting the flying fox by having light-colored fruits – they are an integral part of the rainforest ecosystem. The Spectacled Flying Fox has been record as drinking both fresh and sea water whilst skimming over the surface – a hazardous pursuit as crocodiles at the ready, will snap them up for dinner !!
Females reach sexual maturity at two years of age. Mating occurs between March and May with a gestation period of some 7 months. During this period the males and females separate. Females will migrate to their traditional camps to give birth. The males follow soon after to prepare and protect the females and newborns, remaining monogamous throughout this period. Babies are weaned at approximately 4 months of age.
Predators include the crocodile, carpet python, white-breasted sea-eagle, paralysis tick, and, of course, humans. They are eaten by humans and have been considered as an economic food source.
They are listed as vulnerable, however, their numbers are healthy within their limited territory.
→ Little Red Flying Fox
(Pteropus scapulatus)
The Little Red Flying Fox is the smallest of Australia’s native Flying Foxes, and are primarily found along the eastern and northern coastal areas – though they have been sighted in the arid landscapes of inland Australia as well. They have the largest distribution, often congregating in ‘camps sites’ near water bodies. They are known to ‘hang-out’ in many different habitats, such as swamps, mangroves, and bamboo stands. Little Red Flying Foxes do not echolocate, they communicate via vocalisation, tactile and smell.
Little Red Flying Foxes – on their Evening Quest for Food
Little Red Flying Foxes are essential pollinators, like bees, and critical to the health and reproduction of flowering tree species in Australia.
The feed at night and rest by day.
Eucalypts appear to be a favorite, as they tend to follow the trees’ flowering cycle over great distances, and, further into the Australian interior than any other bat species. They migrate seasonally from rainforests to arid or coastal areas, roosting wherever their favourite flowers, fruits and nectars are in season.
The average wingspan of a male can vary from 0.9 to 1.2 m, reaching weights of up to 550 g. Their life span is, as yet, undetermined. Little Red Flying Foxes congregate in huge camps (100,000’s can congregate in one camp !!!), especially during the 2 month mating season and also, for the lactation period, after giving birth, of some 5 months. Lactating females feed their young until they are close to adult size, which means that the mothers must provide all the calcium that is required to grow the baby’s skeleton. Sadly, this is often to the detriment of the mother who is at risk of osteoporosis from the lack of calcium – resulting in brittle bones – should a bone break, they will be unable to fly and are therefore highly likely to die of starvation . . .
The main threat to the Little Red Flying Fox is humans, who, have not only chopped down the trees and thus the flowers and fruits on which they depend, but also hunt and poison them because the Flying Fox will feed in orchards, when their other food sources are not available . . .
The Little Red Flying Fox is considered common, but is legally protected in Australia. Though their habitats are disappearing and they are culled by farmers, they are not yet considered endangered, threatened, or vulnerable . . .
→ Black Flying Fox
(Pteropus alecto)
The Australian Black Flying Fox is generally found on coastal perimeters up to 250 km inland, up to the latitude of 29º S – primarily in the Northern Territory. They mainly frequent rainforest, eucalyptus open forest, and savanna woodland, roosting in bamboo, rainforests, and mangrove forests. They are identified by their black body and head. Some may display brown ring around their eyes and often have a reddish collar on the back of the neck. Their legs have fur to their knees and are hairless below the knee. They generally weigh around 670 g. Their longevity is speculative, however estimated at at least 7 years of age in order to maintain a stable population.
Contrary to the fixed months of birth of the other species, the Black Flying Fox appears to give birth in times of high food availability. Information about this species is relatively sparse, however, it appears the young are completely dependent for up to 4 weeks, after which they are left at camp whilst the mothers forage for food. At 2 – 3 months of age, babies begin to fly – they are weaned at approximately 5 months of age. It appears the males do not take a parental role . . .
Females mature more quickly than males, reaching sexual maturity at around 2 – 3 years of age.
The Black Flying Fox roosts by day and feeds by night.
They feed on fruits, pollens, and nectar of some 23 rainforest species, depending upon the time of year. During the dry season, they forage mainly in Eucalyptus open forest – during the build-up season, in the Melaleuca open forest – during the wet season, in rainforest. Their eating habits would suggest that the Black Flying Fox plays an important role in connecting isolated fragments of rainforest by transporting seeds and pollen between their feeding sites.
Little is known about predators to the Black Flying Fox, however, habitat clearing and culling by farmers would have to rate the highest. They are currenly not listed on any endangered or threatened species registers.
