The Current Status of the Island Fox


An affiliated group of management agencies, landowners, academics, and non-profits concerned with the conservation of the island fox has convened since 1999 to exchange information regarding the status and trend of the six island fox subspecies, and to work cooperatively on island fox conservations issues in such areas as captive breeding, wild population management, veterinary issues, and educational/outreach. In the most recent 2011 meeting of this group, the Island Fox Working Group, data was presented that indicated that 4 of the 6 island fox (Urocyon littoralis) subspecies were stable or increasing, with high survival, though island foxes still face potential threats from pathogens and predation.

Current Status on Santa Cruz Island
Endangered, but nearly recovered. Captive breeding ended in 2008 for the Santa Cruz Island Fox (Urocyon littoralis santacruzae) and all foxes were returned to the wild. Survival remains very high, and the populaiotn has increased steadily. Some areas now show less increase (fewer pups) as the population nears historic density.

Current Status on Santa Rosa Island
Endangered, but recovering. Captive breeding continued for the Santa Rosa Island fox (Urocyon littoralis santarosae) until 2008 when all foxes were returned to the wild.The annual survival rate climbed to 90% in 2007-2009, but the incidental arrival of three juvenile golden eagles in spring 2010 caused survival to dip in that year. Since then survival has climbed above 90% and the fox population continues to increase.

Current Status on San Miguel Island
Endangered, but nearly recovered. Captive breeding continued for the San Miguel Island fox (Urocyon littoralis littoralis) until 2007 and all foxes were returned to the wild. The population continues to increase by about 25% per year with a high annual fox survival rate, 90%. As of 2011 the population had reach pre-decline levels (close to 400 adults) and can be considered biologically recovered. As the population has reached known historical levels, biologists are watching to see how the population stabilizes. Monitoring foxes via radio telemetry collars has also provided early identification of predation or disease threats. Annual vaccination of 60 - 100 individual foxes is protecting a larger potential survivor group in the event of introduced rabies or distemper virus.

Future Prospects of Threats to the Species
The IUCN Red List of Endangered Species still lists the Island Fox as critically endangered as of a 2008 assessment. The US Fish and Wildlife Service will likely release a draft island fox recovery plan in 2012. Monitoring and mitigation of known threats (eagle predation and canine disease) will be a prominent recovery action in the plan. Island foxes may be vulnerable to impacts of future global climate change. Such impact could be direct, such as changes in acceptable temperature ranges, or indirect, such as impacts on floral or faunal food sources for the fox. Alternatively, global climate change may affect the distribution or virulence of pathogens, such as bacteria or parasites.


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