Fifteen foxes. That was the count on San Miguel Island at the end of the 1990s, on an island that had carried about 450 of them, a population so small that biologists could have known every animal by name and very nearly did. In 2024, field crews trapping and collaring across the same windswept ground tallied roughly 322, according to the Island Fox Status Update 2025 compiled by Friends of the Island Fox from the May 2025 island fox working group meeting. Between those two numbers sit two deeds with hard counts attached: 44 golden eagles captured and relocated off the northern Channel Islands, and 226 captive-bred foxes released back into the wild.
The U.S. Department of the Interior called the result the fastest successful recovery of any mammal listed under the Endangered Species Act when it removed three island fox subspecies from the list in August 2016. San Miguel’s fox was one of them.
An island of fifteen
The island fox is a small animal working a small world. Descended from mainland gray foxes that reached the Channel Islands thousands of years ago, it shrank to about the size of a house cat, one distinct subspecies per island, six islands off the coast of Southern California. San Miguel, the westernmost of the northern group, is barely 14 square miles of fog, dune, and coreopsis, which means its entire fox population has always been a rounding error by continental standards. Four hundred fifty animals was a healthy island. Fifteen was something else.
The crash did not stop at San Miguel. Interior’s accounting of the collapse lists Santa Rosa falling from 1,780 foxes to 15, and Santa Cruz falling from more than 1,400 to 55. Three islands, three populations reduced to remnants within a few years of each other, which is the signature of a shared cause rather than local bad luck.
The cause traced back through a chain that started with a pesticide. Bald eagles, which nested on the islands and fed largely on fish and carrion, were wiped out by DDT contamination in the mid twentieth century. Their absence opened the door for golden eagles, which hunt mammals, and which found on the northern islands an ample supply of feral pigs, piglets in particular, that could support a resident raptor population. Foxes, small and diurnal and evolved without any aerial predator worth fearing, became easy supplementary prey. On Santa Catalina, a separate blow arrived in the form of canine distemper, which tore through that island’s foxes at the end of the 1990s.
Forty-four eagles out, 226 foxes back
The response had to work on several problems at once, because removing one link in the chain without addressing the others would simply have reset the trap. Between 1999 and 2006, according to Interior, 44 golden eagles were live-captured and relocated off the islands to the mainland, an operation that required netting large raptors over rugged terrain and moving them far enough to discourage return. Between 2002 and 2006, 61 bald eagles were released to reoccupy the territory the golden eagles had used, restoring a nesting raptor that does not hunt foxes. On Santa Cruz, more than 5,000 feral pigs were removed in 2005 and 2006, closing off the food supply that had made the islands worth a golden eagle’s time in the first place.
Meanwhile, the foxes themselves went into captive breeding pens on the islands. Interior’s tally is 226 foxes returned to the wild from those programs across the affected islands, animals bred from founders pulled in when wild populations were too small to survive predation. Vaccination against canine distemper, a direct answer to the Catalina outbreak, became standard practice and remains part of annual health checks today. None of this was quick, and none of it was hands off. Recovery here meant a decade of trapping, transporting, penning, releasing, and counting.
By 2016 the arithmetic had turned. The San Miguel, Santa Rosa, and Santa Cruz subspecies were delisted as recovered, and the Santa Catalina fox was downlisted from endangered to threatened.
What 322 counts, and what it does not
The 2024 numbers compiled by Friends of the Island Fox show San Miguel at roughly 322 foxes, down from about 525 the year before. That drop is not a relapse. Small islands run their populations up against food and space, and fox density on San Miguel has swung above and below its long-term carrying capacity more than once since recovery, with counts settling back after peak years. Neighboring Santa Cruz, much larger, supported 3,086 foxes in the same monitoring season, which gives a sense of how differently these islands scale.
The picture is not uniform across the archipelago. San Clemente Island, home to its own subspecies, showed a third consecutive year of decline in 2024, with reduced adult survival and only seven pups documented. Biologists have not identified the cause, and the working group has it under investigation. That is the honest state of the file: an open question on one island, not a settled answer.
Delisting also does not mean the monitoring stops. Foxes on every island are still trapped, weighed, vaccinated, and counted each year, because a species confined to a few square miles of land can lose a population faster than anyone can respond without that data. Ear mites, distemper exposure, and novel pathogens all stay on the watch list.
But the San Miguel number holds. Fifteen animals at the low point, 44 golden eagles relocated, 226 captive-bred foxes returned, and roughly 322 foxes counted on the island in 2024.