葡京官网

Wild outlook for captive condors

作者:梅梨筒    发布时间:2019-02-28 08:02:02    

By Rosie Mestel ARTIFICIAL caves with a view of nothing but mountains, trees and sky are the latest ploy in the fight to save the California condor from extinction. Young condors hatched at the Los Angeles Zoo and the San Diego Wild Animal Park will spend the next few months in cages crafted to look like caves – the type of home that their ancestors would have sought in the days when condors flew free. There are now 104 California condors left in the world, a healthy increase from the late 1980s, when the number had fallen to just 27. Conservation biologists are working hard to re-establish the condor in the wilds of California, but have experienced a number of setbacks. In the past few years, one bird died after drinking antifreeze, several others died after colliding with power lines, and instead of shying away from people, the surviving young birds have exhibited a worrying interest in human activities. The “caves” are part of several strategies designed to equip condors for life in the wild. Created out of concrete, chicken wire and foam, the caves are in a remote location and look out upon mountains, streams and sky. This is in stark contrast to the Los Angeles Zoo where birds are reared in plywood and steel cages, to the accompaniment of planes, radios, car horns and people. Later this month, four young chicks will take up residence in the caves. Several months later, they will be moved to a larger holding pen where they will be taught to exercise their flight muscles before release to the wild. In these pens, the birds will learn to avoid power lines with the aid of fake cables that give nasty but harmless jolts of electricity if the birds touch them. The four birds have another advantage over earlier hatchlings: they were reared by their mothers. Until now, eggs have been taken away as soon as they were laid and the young reared by keepers masquerading as adult condors. The eggs were removed largely to encourage the females to lay more, but also in case the mothers in the breeding programme were unable to care for their chicks properly. The hope is that chicks raised by their mothers will be better equipped to cope in the wild and less likely to fly into trouble. “We figure the more we can replicate the natural situation, the better off we are,” says Marc Weitzel,

 

Copyright © 网站地图