Reintroduction - A Delicate Dance
And the presence of golden eagles was a huge controversy, as far as fox releases went. Some biologists wanted us to wait until all eagles had been removed from the islands before reintroducing foxes. Perhaps, in an ideal world...but we were not in an ideal world. The captive breeding pens were full, and at that point, in 2003-2004, there was no guarantee every last golden eagle would be removed. Releasing foxes back into such an environment was definitely a risk.
Reintroduction began in 2003 on Santa Rosa (left) and in 2004 on San Miguel (above).
We began reintroduction on Santa Rosa in 2003 and on San Miguel in 2004. The latter release was fascinating to me. We released 10 foxes, as male-female pairs, in several areas of the island; all had radiocollars and we tracked their whereabouts. They were released into what I saw as ideal conditions: an island devoid of other foxes, no one else’s territory to run into, plenty of food for everyone. And the most amazing thing to me was that they found each other. By the following spring there were four mated pairs among this group, and they all had pups, which we observed on cameras we set near island fox dens. We were off and running.
Radiotelemetry told us we had mated pairs after our first year of releases on San Miguel.
Those mated pairs produced pups, which showed up on trail cameras.
We released foxes on all three northern islands over the next several years, and incurred some predation mortality before the last eagle was removed in 2006. But by this time the newly released foxes were recovering themselves. They were surviving, and breeding at a higher rate than they were in captivity, so much so that it made perfect sense to release all foxes and let them do their thing in the wild. Accordingly, by 2008 we had released all remaining foxes to the wild, and shuttered the captive breeding facilities, which today are like ghost towns on the islands. The ever-present wind blows island fog through the deteriorating pens, and, like ghost towns, it’s hard to believe they were ever inhabited. But for a decade the captive pens not only safeguarded the remaining island foxes, but formed the nucleus, the warp-core, of recovery. Had captive breeding not worked, this would be a different tale to tell, one of irretrievable loss.
But this is a success story, one in the “W” column. It only took 10 years of captive breeding to kick-start island fox recovery. After that, the foxes took over. It’s all in the numbers. In 1999-2000 there were only 15 foxes left on San Miguel, 15 on Santa Rosa, and less than 100 on Santa Cruz. Fast-forward to 2013: over 500 on Miguel, over 700 on Rosa and 1100 on Santa Cruz. Over 250 foxes were released to the wild on the northern islands from 2003-2008.
