Race Is On to Save Foxes From Eagles’ Clutches
A life-and-death struggle has intensified on the Channel Islands off Ventura County as scientists hurry to intercept hungry eagles poised to gobble the few remaining island foxes in a feeding binge.
Spring is in the air, and golden eagles preparing to nest on the islands are launching voracious airstrikes against prey, including feral pigs and rodents, which also are multiplying as grass grows. Trouble is, the big raptors zap too many tiny island foxes, the unofficial mascot of the islands.
In an attempt to tweak the food chain, researchers have doubled their efforts this year to remove golden eagles, which are not native to the islands, and capture many of the remaining foxes before the avian predators find them. The drama plays out on San Miguel, Santa Rosa and Santa Cruz islands, which are part of Channel Islands National Park.
If all goes well, the eagles could be evicted by summer, and foxes paired with mates in captivity could begin breeding their way back from the precipice of extinction.
“We are full bore on eagle removal,” said Tim Coonan, biologist for Channel Islands National Park. “This spring is critical to success. This spring will determine if the species can survive on the islands or not.”
Last May, a team of experts concluded that foxes inhabiting the park islands were in immediate peril of extinction due to predation, heartworms and damage to their native habitat. They embarked on a radical solution reserved for critical species such as condors and bighorn sheep--rounding up surviving animals in pens to begin captive breeding.
Fox populations on the northern Channel Islands have declined 90% in five years, making them one of the most threatened canine species in North America. Only 15 foxes remain on San Miguel Island, a stronghold for 450 of the animals not long ago. Related subspecies of fox on other Southern California islands are faring better, but recent surveys show their numbers are mysteriously declining too.
The recovery effort came under sharp criticism from environmentalists and some scientists late last year. No attempts were made to save foxes on Santa Rosa or Santa Cruz islands, and money to capture and relocate eagles to Northern California was running out.
An infusion of $266,000 in federal funds this year, however, has reinvigorated the fox-protection effort. Pens are being built to hold foxes removed from the wild on Santa Rosa Island. And more eagle trappers are being deployed. Using bunnies for bait, they are taking advantage of the eagles’ surging appetite and nabbing them with nets as they hunt.
About 15 golden eagles have made the northern islands their home, filling a niche left after bald eagles succumbed to DDT poisoning 30 years ago. A bounding population of wild pigs, left behind by farmers who once tilled the islands, sustains the birds. Five eagles, including three last month, have been removed so far, and Coonan said the goal is to catch the rest by June. The work is being done by the Predatory Bird Research Group at UC Santa Cruz.
“These additional monies are helping us achieve our goals that weren’t being met before,” UCLA biologist Gary Roemer said. “This is a very important year for the fox recovery program.”
Meanwhile, scientists are giving more than a dozen foxes caged on San Miguel Island every opportunity to mate. They watch them around the clock with video cameras, but otherwise are hoping the four males and 10 females will do what comes naturally.
“If they breed now, there will be litters by April, and we might be able to release animals this fall if we lick the eagle problem,” Coonan said.
