A recent study reveals that the efforts to reintroduce Galapagos giant tortoises to their native Española Island have been a success. These tortoises, a critically endangered species had been over-hunted and displaced by invasive species in the 1960s. The researchers revealed that there were only 15 lumbering giants that remained alive. Therefore, the scientists captured all of those survivors in order to keep them safe and to try to breed them.
The tortoises did indeed breed over the years, but meanwhile, a massive feral goat eradication campaign was undertaken by the Galapagos National Park Service. In the late 19th century, goats first invaded the island and those ravenous animals quickly ate up much of the native vegetation. With the goat problem tamed, researchers could progressively begin to reintroduce the tortoises.
Now, the goats are gone, and around 1,000 tortoises live on the island. Researchers told that they are successfully breeding on their own. The authors of the new assessment stated, “It’s a rare example of how biologists and managers can collaborate to recover a species from the brink of extinction.”
However, the restoration job is far from finished. Much of the island is still covered in shrubby, woody underbrush that took over after the hungry goats were extirpated, researcher revealed. Those types of hostile pioneer plants prevent other species, such as the native arboreal prickly pear cactus, from growing.
Although, tortoises need cactus as a major part of their diet. So until the island’s flora can be restored to something resembling pre-goat times, the tortoise population will probably upland at about the levels it’s at now. The researchers said, “Population restoration is one thing, but an ecological restoration is going to take a lot longer.”