For the second time in three months, a cadre of golden eagles on Santa Cruz Island has outfoxed a helicopter crew trying to capture them, leaving frustrated wildlife managers to fall back on more traditional trapping methods.
The helicopter, aided by 20 spotters on the ground, spent the week chasing the powerful birds across steep ridges, into canyons and along sheer sea cliffs. But whenever the helicopter closed in, the eagles slipped away, ducking for cover beneath trees and ledges. The effort -- intended to help the endangered island foxes -- was finally called off Thursday.
Compounding the problem was the discovery that there are seven golden eagles on the island rather than the three recorded in July.
"One eagle managed to give birth and the others probably came from the mainland," said Kate Faulkner, chief of resources management at Channel Islands National Park. "They are masterful fliers and can come across the channel with ease. They see other eagles circling above and think it's good feeding territory."
The birds are being removed from Santa Cruz, the largest of the Channel Islands, because they prey on the island fox. Many of the cat-sized foxes have been trapped and put in pens until the eagles are captured.
There are now 91 foxes living in captivity on Santa Cruz, Santa Rosa and San Miguel islands. The golden eagles nest on Santa Cruz but can roam to the other islands.
With the failure of helicopter trapping, park officials will return to bow nets, with which 22 golden eagles initially were caught starting in 1999 but which have since proved ineffective. The folding traps are baited with feral pig carcasses and buried. When hungry birds step into them, the traps snap shut.
Bow nets were abandoned after the last few birds, having watched others get gradually picked off, learned to avoid them.
Wildlife officials then borrowed a technique used in Wyoming. It involved chasing eagles with a helicopter until the birds tired and landed. The aircraft then hovers above, and a biologist perched in the door launches a net from what resembles a modified shotgun. Another crewman then leaps out and subdues the floundering animal.
But Santa Cruz Island, with plunging valleys and mountains rising to 4,000 feet, has proved more formidable than the open grasslands of Wyoming. Along with rugged terrain, foggy island weather has made helicopter netting almost impossible.
