Grey-headed flying fox

Grey-headed flying fox with wings outstretched

The Grey-headed Flying Fox ( Pteropus poliocephalus ) is a living in eastern Australia kind of flying foxes from the group of authentics bats.

Features

The Grey-headed flying fox is one of the largest bat species that occur in Australia. It has a wingspan often includes a meter, in some cases up to 1.5 meters. His body is dark gray, the head is light gray. What is striking is his red-brown shoulders. The wing membranes are black. Like all bats he has no tail. Claws sit on the first and second fingers. The species is the only one among the bats, in which the coat reaching to the ankles, with other species, it only goes up to the knees.

The body length is 23-29 centimeters, average these bats are 25 inches long. Its weight is 600 to 1000 grams, some specimens can reach more than 1 kilogram. Your arm has a length of 13.8 to 18 centimeters.

The head is similar in this subgroup of bats in the form of a fox or the dog, which has led to the English common name of Flying Fox and the German name flying fox. You are not oriented by echolocation by ultrasound, but are dependent upon flight on their big eyes. Therefore, the characteristic of other Fledertiergruppen hearing organs missing.

Dissemination

Grey-headed flying foxes are common along the east coast of Australia between Bundaberg in Queensland through New South Wales to Melbourne in the state of Victoria. They inhabit a relatively narrow coastal strip up to the western slopes of the Australian Cordillera ranges in the north of New South Wales, in the south it is somewhat narrower and includes only the area east of the mountains.

The area of ​​distribution has decreased in recent times especially in the north, earlier it was enough to Rockhampton in Central Queensland. The cause of climate change and the associated encroachment of the Black flying fox is considered in the distribution area of the Grey-headed flying fox. It is believed that the habitat in which the gray-headed flying fox occurs, has increased in the south, but lacking accurate data. Anyway, included the populations of flying fox in the 1930s still several million individuals, today there are only a maximum of 400,000. Alone between 1989 and 2001 took the stock off by 30 percent.

Way of life

At dusk they leave their resting places - Camps called - and go in search of food. They can in one night up to 50 kilometers to cover to reach seasonal or only in certain areas occurring food sources. Their diet consists of nectar, pollen and fruit of different plants, such as eucalypts, banksias and Myrtenheiden. They follow the people in the suburbs, where they also feed on plantation crops, such as mangoes, figs and grapes. They are therefore persecuted as pests in these areas. Unpopularity they are close to the settlements also because of the strong odor in the vicinity of the camps, spread the especially the males. Their ecological importance is the dissemination of pollen and seeds of the plants they visit.

The females give birth to only one offspring per year, which comes after a six-month gestation period in October or November to the world. In the first three weeks the cub in the evening flights is supported. In the following two months the boys stay on the roosting trees, because they are not yet capable of flight and are suckled by their mothers. Only at the age of about three months, they also leave the camps, but they are weaned until six months and then feed on their own.

Endangering

The decrease in inventories was mainly due to the clearing of coastal forests in favor of settlements and agricultural land. From the deforestation also many food plants of the Grey-headed flying fox are affected. Especially in the winter they will lead to food shortages, especially in the offspring. Disturbance of beds by the people and the persecution of bats in the vicinity of settlements added. Risk by power lines and fences, where injury to the animals.

Between 1994 and 2002, died at 19 days when the daytime temperature rose to about 42 ° C, approximately 24,500 Grey-headed flying foxes to overheating ( hyperthermia). On January 12, 2002 in the Australian summer, alone, there were 1361 animals. 92 orphaned and dehydrated pups could be collected and cared for. The number of days on which there is extreme heat in South Australia has increased over the past decade. With the higher average temperatures in is also associated with the spread of the black flying fox which has penetrated 500 km far into the habitat of the Grey-headed flying fox since 1990. The area of the black flying fox in northern Australia is limited by the frost, which prevails on some winter days in the south and is of this type bad bear. The milder winters caused by global warming, however, have shifted this frost line. This results in diminishing resources another food competition for the Grey-headed flying fox.

The type was therefore 'at risk' on in 2008 on the IUCN Red List of " safely " ( " least concern ") (" vulnerable" ) upgraded.