Fraggle catching food tossed into the air by Gary

This month’s Bird of the Month is FRAGGLE our WHITE-BELLIED SEA-EAGLE

The White-bellied sea-eagle is also known as the White-bellied Fish-eagle, the White-breasted Fish-eagle or Fish-hawk. These birds belong to the family Accipitridae and the species name is Haliaeetus leucogaster. A large female can weigh up to 8.5lbs (3.9Kg) and have a wingspan of around 6.5ft (2m). As can be seen from the photograph, they have areas of white feathering, which is a common feature of those birds that have a large amount of fish in their diet. Amongst several theories for this feature is the possibility that the white patches break up the silhouette of the bird when viewed from below and that the fish may then feel safe enough to swim near the surface. Unlike other eagles, these birds do not have feathering on their legs, so they can possibly be classed as giant kites rather than eagles. This also makes it possible to confuse them with the smaller Osprey. The bare legs and feet are heavily scaled as armour, and the soles are covered in tiny spikes to aid in holding slippery prey. Sea-eagles flap their wings slowly and soar or glide with their wings held in a shallow V. They call with a loud goose-like honking, and this is a familiar sound here at the Conservancy.

The distribution of White-bellied Sea-eagles is along the coastlines of India and east through south-east Asia, southern China and down through Indonesia, the Philippines and New Guinea to Australia. They are also found in tidal estuaries, rivers and lakes in these regions.

Fraggle in flight - front view

As suggested by the name, their diet consists mainly of aquatic vertebrates, including reptiles, fish, birds and mammals. They also take crustaceans and will scavenge carrion on the shorelines and human waste from rubbish tips. Amongst the reptiles taken are venomous sea-snakes and turtles. Birds such as gulls, terns, young herons, cormorants, and roosting fruit bats are preyed upon along with mammals like rodents, wallabies and occasionally domesticated species. When catching their prey they usually do so with a backward slash of the talons of one foot. Over water they will scoop the victim from close to the surface rather than plunging as an Osprey would do. Naturally they have outstanding eye to talon co-ordination; this is vital when catching sea-snakes.

Sea-eagles will mate for life, and build huge stick nests, which they may use for several years. Pairs will display to each other with a good deal of calling and aerial displaying, including talon-grappling and cartwheeling. The clutch is normally two eggs, which incubate for 35-42 days.

Fraggle was hatched in Singapore in 1983 and came to the Conservancy in 1989 as a gift from Jurong Bird Park in Singapore. In return for us helping to train one of their staff in the art of demonstrating birds of prey, they kindly gave us a pair of these magnificent Sea-eagles. We had high hopes for the very handsome Fraggle and his partner Gypsy, but unfortunately she hated him and tried to kill him on a couple of occasions.

Fraggle in flight showing the large areas of white.

There being no marriage guidance in the world of Sea-eagles, we had to separate them and Gypsy now lives a happy but solitary life in a corner of the park, while Fraggle gets all the glory when demonstrating his flying skills in our Valley of the Eagles display. He is probably the most reliable and consistent member of our flying team and can always be relied on to give his marvellous performance even in the foulest weather conditions when most sensible birds take shelter. He can be seen making wonderful stoops to catch food thrown up to him which he then takes to pick over very carefully on a favourite perch, just as he would do in the wild. Despite being such a good-natured and competent performer, Fraggle does have a couple of faults. The first is that he will not bathe in the still water of his bath; he will only bathe in running water. This means that about once every ten days or so, he will appear for his demonstration, completely ignore his handler, and continue to fly away from the audience down into the local river valley. There he will bathe himself and then go and sit in a favourite tree to dry off, before returning an hour or so later, usually in the middle of the next flying display where he frightens the other birds. Fraggle is also very shy and will only display if he is released out of sight of the audience. Once in the air he has confidence in the crowd below, so long as they are all seated in the viewing arena. However, on public holidays when there may be upwards of 750 people watching the displays, some members of the audience are required to sit on the grass to one side of the arena. When Fraggle looks down on this sight, he seems to think that these people have escaped from the ‘human aviary’ below, and he takes fright and flies off into the valley. There he will sit until the park closes and the crowd have gone home. This is not the best of habits for a performer in the entertainment business! Despite these minor flaws, Fraggle is one of the most popular birds with both staff and visitors and will hopefully be one of the leading stars of the Valley of the Eagles display for many years to come.