November 12, 2009
Croatia’s Griffon Vultures Return To The Wild
After being rescued, the last of eight griffon vultures was fitted with a satellite transmitter before being sent off into the wild last month from the northern Croatian island of Cres.
Though the vulture seemed hesitant to leave its place of safety for a long migration, its instincts finally kicked in and it took off in search of food, reported AFP.
However, this is the first time that the birds have been sent off with satellite transmitters, tracking data on their location, altitude, speed and course that they can stay on for years.
Only two of the birds were fitted with this technology, while others are marked with less expensive rings and wing-tags for identification and monitoring, which helped to identify one of the Croatian birds that was found in Chad, in central Africa.
"When I saw them flying for the first time, I was fascinated," said Goran Susic, a 51-year-old ornithologist who runs the sanctuary.
At the start of the project, Cres only housed about 20 pairs of culture griffons. But there are now around 70 pairs, which is more than half the species total number of pairs in Croatia where they inhabit the four northern islands.
The birds still face many risks, including the decline of sheep farming, since the scavengers primarily subsist on sheep carcasses.
Other risks sneaking up on them is the devastation of their habitats through urbanization, tourists disturbing their nests, and the accidental poisoning they suffer as farmers try to poison wild boar.
The Croatian griffon vultures are the only ones which have nests as low as 33 feet above sea level, often kept in cliffs so high that the young can easily fall into the ocean.
The birds are quite sizeable, having a wingspan of eight to nine feet, making the first shelter at Beli too small for them to inhabit.
"They were kept in rather poor conditions, in an overcrowded cage where they could not fly until they reached a sufficient weight to be released. Although we were saving them, it was a kind of torture," Susic recalled.
In May, a shelter 20 times larger was opened whereby the public can visit and observe the birds from a special viewing room.
The shelter has also worked to make the birds' reintroduction into the wild less traumatizing.
"Before we transported them in boxes or bags to the top of the island where they were kept in small cages overnight prior to be released," Susic said. "It was an enormous stress that we wanted to diminish."
In order to make their release less stressful, this year the eight birds were separated the night before their departure in a part of the sanctuary.
For now, four birds are going to stay in Beli, as for various reasons they cannot survive in the wild. Eleven are being cared for until their scheduled release in 2010, by when they should have learned to eat, fly and behave in a group.
Until they reach the age of five, the birds of prey fly across Europe and parts of Asia at a height of 19,800 to 23,100 feet and speeds up to 100 miles per hour. At that point, the survivors return to nest on Cres, where a pair, which mates for life, has one young about every two years.
Griffon vultures may have a poor sense of smell, but they more than make up for it with their keen vision. They are able to communicate through wing signals at a distance of up to six miles.
"Maybe their troubles are just beginning as they go back in the wild," said Angela Flemming-Pedersen, a Swiss visitor to the sanctuary.
Spain is the only European country where griffon vultures are not endangered, and is home to 18,000 pairs, or 95 percent of the species in Europe.
There are currently programs in place to reintroduce the birds of prey in many countries where they are extinct, including Bosnia, Bulgaria, France, Israel and Italy.