As Swift mentioned, we did have plans on doing six videos for the Channel Island Fox species but after a lot of research, we decided to just do one and focus on two very important details.
As we posted back in Part 6, these six species are the descendants of the gray fox, getting a unique chance to evolve perfectly to fit in their island habitats. Each island fox is notably smaller than nearly all of the other mainland foxes, perhaps coming closest to the swift fox by comparison, but weighing between two and six pounds.
For centuries, the various island foxes shared their home with bald eagles and the ecosystem was perfectly balanced. However, as bald eagle populations dwindled due to DDT poisoning, these birds soon vanished from the islands, eventually being replaced by golden eagles. Being a non-native predator to these islands, the golden eagles preyed upon these small foxes, which caused their populations to crash.
The largest decline took place in the mid-1990s, causing each species to end up on the critically endangered species list. In fact, things became so bad that at one point, San Miguel Island only had fifteen individual foxes left. Drastic measure had to be taken.
A massive recovery project was launched. Captive breeding and release initiatives for these foxes were seeing major success along with the humane removal and relocating of the invasive golden eagles (and some reintroduction of the once native bald eagles). Today, these six fox species have made an amazing come back and are now only listed as “of mild concern” on the species list. It’s incredible how quickly these programs worked in saving these foxes.
And it’s a good thing too, for as Swift pointed out in the video, each of these fox species are keystone species. A keystone species is an animal that is so important to its ecosystem and food web that if it were ever removed, the local environment and even the physical landscape itself can be devastated. In this case, deer mice populations had begun to rise and plant life was being lost at an alarming rate. If things had continued along that way, the mice would have destroyed the local vegetation, which in turn would have led to massive erosion problems and a loss of food for other local herbivores.
This type of keystone species loss has already been seen in Yellowstone with the loss of the wolves. Everything in the park was negatively impacted but it took scientists and biologists a long time to put the puzzle pieces together. Between an explosion in elk populations (which lead to a loss in tree and other plant life) and in the coyote population (which lead to a loss in smaller animals as prey items), the park’s ecosystem was falling apart. Even the riverbanks and mountains were suffering terrible erosion problems as a result. And it all changed with the reintroduction of the wolves. Everything balanced out properly: populations of the animals returned to normal, the plant life returned and even the riverbanks began to take their old shape again.
It really is amazing how these animals, especially these tiny foxes, can be so hugely important.