Santa Cruz Island And Wild Pig Eradication From Helicopters

Success with mixed results.
 
In April 2005 the Los Angeles Times published an article by Gregory Griggs on the removal of wild pigs on Santa Cruz Island off the coast of California. The boar had to be removed in order to ensure the survival of the Santa Cruz Island Fox, a cat sized fox.
On the behest of the National Park Service under its director Tim Setnicka, an avid proponent of wild pig eradication, traps, helicopter based snipers and finally ground based hunters with dogs were employed together with sterilized Judas pigs that lead the expert hunters to the last and smartest boar. In 411days 5036 wild boar were 'removed' from the island. Though helicopter based shooters eliminated the majority of wild pigs, the biggest, smartest and most cunning boar fell victim only to expert hunters and their dogs.

At the start of the eradication the entire 98 square miles of the island were divided into five fenced eradication zones. Wild pig eradication followed a carefully orchestrated plan. It began with trapping (16% of dispatches in 1660 trap-nights), then proceeded to aerial shooting from helicopters (77% of dispatches in 13,822 km of flight path) and ended with the use of ground based hunters with dogs and sterilized Judas pigs leading the hunters to their quarry (5% of dispatches in 1111 hunter-days)(according to http://www.sciencedirect.com/science/article/pii/S0006320709004935.) Only about 10 percent of the last 102 pigs (about 20 per fenced zone) had to be found and killed with the help of telemetered traitor pigs. After normal hunting stopped radio-collared boar assisted in removing 43 percent of the very last survivors.
Helicopters were useless in finding and destroying them. These few last survivors would have been enough to repopulate the island slowly.


The entire operation was vehemently opposed by animal rights activists, the group In Defense of Animals and other interested parties.  It eventually lead to a law suit.


In order to win support for the eradication program the Park Service and the Nature Conservancy, which owns 75 per cent of the island, had to establish an enemy. They found it in the wild pigs by accusing the animal of attracting Golden Eagles to the island. The eagles preyed on piglets and foxes alike. But they made a convenient excuse for the eradication program.


The plan was to remove the boar  first, then eliminate the eagles and thus restore harmony and ecological balance to the island.
Forty-four pairs of eagles were removed. At least one pair eluded capture successfully. Bald Eagles had to be introduced to get the last and most resilient of Golden Eagles off the island. I could not find any indication in literature anywhere that even one pig survived.


Though island foxes and some plant life affected by foraging boar regained strength, other unintended animal beneficiaries of the mass eradication surfaced.
Bald eagles may be one of them. They began to prey on island foxes on a neighboring island. Wild turkey are another. They started to proliferate as soon as the boar were gone.  Moreover, the endemic skunk population has increased considerably in numbers due to reduced competition.

Looking at scientific literature and research papers it appears more and more that the ideal of restoring an environment to its 'pristine' state before Europeans changed its nature through their activities is not achievable without trade-off. At least not in the idealistic way the Nature Conservancy and some members of the National Park Service envision it.

Controversial as it was, at least the elimination of wild pigs from Santa Cruz Island was not called 'hunting' wild pigs from helicopters. Unlike in Texas where the self-interest of wealthy ranchers to shift the cost of removal of their boar to the public, helicopter owners and paying guests has created "wild pig hunts from helicopters" by Vertex.
PJJ