The San Miguel and Santa Cruz subspecies are suffering from high predation rates by golden eagles. Historically, golden eagles did not occur on the Channel Islands. Because bald eagles are highly territorial with respect to other eagles, their extirpation due to DDT and other factors opened up a niche for golden eagle colonization. Golden eagles have also benefitted by the introduction of exotic pigs to the islands. While bald eagles primarily prey on fish and are thus not a threat to the island fox, golden eagles prey extensively on land mammals, including feral pigs and island foxes.
Efforts are underway to restore bald eagles, relocate golden eagles, and remove feral pigs.
If completed, these efforts will greatly reduce predation pressure on the island fox. The Santa Catalina subspecies' catastrophic decline appears to be linked to canine distemper. This disease was likely contracted from domestic dogs despite regulations designed to prohibit or limit dogs on many of the islands. All island fox populations are impacted by the past degradation of native habitats by introduced livestock and game species.