At a Marine base, tortoises decline while ravens thrive

Mojave desert tortoise numbers are on the decline at Marine Corps Logistics Base Barstow. ©Laurie Pearson

At a Marine Corps base in the Mojave Desert, biologists were finding that as ravens (Corvus corax) were increasing, endangered Mojave desert tortoises (Gopherus agassizii) were declining. Historically, ravens had trouble surviving in the desert conditions of the Marine Corps Logistics Base Barstow, but expansions of highways and powerlines gave them places to nest, and human food trash helped them thrive. The birds also prey on tortoises — even health adult tortoises — and their eggs, exacerbating the species’ decline. “There is a direct correlation to an increase in raven population,” Cody Leslie, natural resource specialist for the base, told the Defense Visual Information Distribution Service. “When I say ‘direct correlation,’ I mean that as the tortoises are decreasing in population, the ravens have increased by as much as 1,500 percent. That’s a huge increase.” The base’s Environmental Division is working to protect the tortoises and decrease the raven population.

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