15 August 2005
CSG Scientists call for urgent action to save the endangered Island Fox
Press release: 27 November 2003
We wish to express grave concern about current approaches to the management of the Island Fox Urocyon littoralis, a Critically Endangered species endemic to the California Channel Islands. Three island-endemic subspecies (all candidates for listing under the U.S. Endangered Species Act), restricted entirely to the Channel Islands National Park and land owned by The Nature Conservancy, face an imminent risk of extinction if management is limited to the techniques currently available.
Island foxes suffered catastrophic declines in the northern Channel Islands, such that two subspecies are now extinct in the wild and a third, that on Santa Cruz Island, has a wild population that declined from ~ 1500 (1994) to 133 (1999) to perhaps as few as 65 this year (2003). These population crashes were the result of predation by golden eagles, which colonized the islands naturally in the 1990s. Eagles have foraged preferentially on foxes but are not sustained by them; substantial scientific evidence suggests that introduced feral pigs, deer and elk sustain the breeding eagle population.
As insurance against total extinction, the National Park Service (in partnership with The Nature Conservancy on Santa Cruz Island) established captive breeding facilities for all three subspecies. Breeding success has been low. Nevertheless, all three facilities were at capacity, and foxes were therefore recently released into the wild on Santa Rosa and Santa Cruz. These releases occurred despite continuing eagle presence on both islands, and continued eagle predation on wild foxes on Santa Cruz.
Thus far, conservation efforts for the remaining wild foxes have involved removing golden eagles by various non-lethal means. The skill and dedication of the staff involved are to be praised; in total 31 eagles have been live-captured and translocated to distant locales. However, despite months or years of effort, a small number of golden eagles (possibly as few as 4 birds) have evaded capture and remain on the islands. Eagle predation is still the major cause of fox mortality on Santa Cruz (35 of 40 radio-collared foxes found dead were killed by eagles), where the only wild population continues to decline. There is very little prospect of recovery of any of the three northern subspecies while the golden eagle population remains.
The next few months will see the start of a program to eradicate feral pigs from Santa Cruz Island. We support the need to remove the pigs: this is important to restore native vegetation. However, we caution that this operation could have devastating consequences in the short term. Eagles denied pigs as prey may well switch to more intense predation on foxes, including those recently released from captivity that likely are more naïve than their wild counterparts. Moreover, the presence of pig carcasses – an inevitable consequence of pig control – can be expected to draw eagles away from established bait sites and further reduce the efficiency of live capture.
Given these concerns we advise, in the strongest terms, that permission be sought to remove golden eagles from the northern Channel Islands by lethal means. Because lengthy administrative processes would be required to approve such permission, the need to pursue this option must be seen as urgent. Lethal control could be targeted at particular animals that have repeatedly evaded capture, or used under ‘emergency’ conditions should fox mortality rise in the course of pig removal. We fully appreciate concerns about killing a protected species that is emblematic of the wild places that conservationists seek to protect. However, we also recognize that, unless golden eagles are removed completely from the northern Channel Islands in the very near future, the prospects for recovery of the three northern subspecies are close to zero. We view this dilemma with the deepest regret, but can see no alternative to extreme action, due to the circumstances that have undoubtedly been brought about by earlier human activities.
More details on these recommendations, and data supporting them, are given in the enclosed paper.
Signed on behalf of the IUCN/SSC Canid Specialist Group:
David W. Macdonald, Chair Claudio Sillero, Deputy ChairTodd Fuller & Rurik List, North & Central America Regional SectionGary W. Roemer, Rosie Woodroffe, Robert Wayne, Cheri Asa & Linda Munson, Island Fox Working GroupScott Creel, Ecology & Research Working Group
For additional information contact the IUCN/SSC Canid Specialist Group, canids@zoo.ox.ac.uk, Tel. 00 44 1865 281264/427543
We wish to express grave concern about current approaches to the management of the Island Fox Urocyon littoralis, a Critically Endangered species endemic to the California Channel Islands. Three island-endemic subspecies (all candidates for listing under the U.S. Endangered Species Act), restricted entirely to the Channel Islands National Park and land owned by The Nature Conservancy, face an imminent risk of extinction if management is limited to the techniques currently available.
Island foxes suffered catastrophic declines in the northern Channel Islands, such that two subspecies are now extinct in the wild and a third, that on Santa Cruz Island, has a wild population that declined from ~ 1500 (1994) to 133 (1999) to perhaps as few as 65 this year (2003). These population crashes were the result of predation by golden eagles, which colonized the islands naturally in the 1990s. Eagles have foraged preferentially on foxes but are not sustained by them; substantial scientific evidence suggests that introduced feral pigs, deer and elk sustain the breeding eagle population.
As insurance against total extinction, the National Park Service (in partnership with The Nature Conservancy on Santa Cruz Island) established captive breeding facilities for all three subspecies. Breeding success has been low. Nevertheless, all three facilities were at capacity, and foxes were therefore recently released into the wild on Santa Rosa and Santa Cruz. These releases occurred despite continuing eagle presence on both islands, and continued eagle predation on wild foxes on Santa Cruz.
Thus far, conservation efforts for the remaining wild foxes have involved removing golden eagles by various non-lethal means. The skill and dedication of the staff involved are to be praised; in total 31 eagles have been live-captured and translocated to distant locales. However, despite months or years of effort, a small number of golden eagles (possibly as few as 4 birds) have evaded capture and remain on the islands. Eagle predation is still the major cause of fox mortality on Santa Cruz (35 of 40 radio-collared foxes found dead were killed by eagles), where the only wild population continues to decline. There is very little prospect of recovery of any of the three northern subspecies while the golden eagle population remains.
The next few months will see the start of a program to eradicate feral pigs from Santa Cruz Island. We support the need to remove the pigs: this is important to restore native vegetation. However, we caution that this operation could have devastating consequences in the short term. Eagles denied pigs as prey may well switch to more intense predation on foxes, including those recently released from captivity that likely are more naïve than their wild counterparts. Moreover, the presence of pig carcasses – an inevitable consequence of pig control – can be expected to draw eagles away from established bait sites and further reduce the efficiency of live capture.
Given these concerns we advise, in the strongest terms, that permission be sought to remove golden eagles from the northern Channel Islands by lethal means. Because lengthy administrative processes would be required to approve such permission, the need to pursue this option must be seen as urgent. Lethal control could be targeted at particular animals that have repeatedly evaded capture, or used under ‘emergency’ conditions should fox mortality rise in the course of pig removal. We fully appreciate concerns about killing a protected species that is emblematic of the wild places that conservationists seek to protect. However, we also recognize that, unless golden eagles are removed completely from the northern Channel Islands in the very near future, the prospects for recovery of the three northern subspecies are close to zero. We view this dilemma with the deepest regret, but can see no alternative to extreme action, due to the circumstances that have undoubtedly been brought about by earlier human activities.
More details on these recommendations, and data supporting them, are given in the enclosed paper.
Signed on behalf of the IUCN/SSC Canid Specialist Group:
David W. Macdonald, Chair Claudio Sillero, Deputy ChairTodd Fuller & Rurik List, North & Central America Regional SectionGary W. Roemer, Rosie Woodroffe, Robert Wayne, Cheri Asa & Linda Munson, Island Fox Working GroupScott Creel, Ecology & Research Working Group
For additional information contact the IUCN/SSC Canid Specialist Group, canids@zoo.ox.ac.uk, Tel. 00 44 1865 281264/427543
