• Andrew Gray/Wikimedia
    9 of 12

    Isthmohyla rivularis frog

    Isthmohyla rivularis, which doesn’t have a non-Latin name, is the rarest species of tree frog in the world. The frogs are natives to rainforests in Panama and Costa Rica, but due to habitat loss, they were thought to have gone extinct in the 1980s. They kept that status for 20 years, and then in 2007, one of the tiny frogs was found by University of Manchester researcher Andrew Gray. In 2008, a female was found in Monteverde Cloud Forest Preserve in Costa Rica. Discovering specimens of both sexes of the species gave hope of fostering a recovery effort. And this year, there was more good news for isthmohyla rivularis. More of the frogs were discovered, although this time in an environment in which they were not previously recorded to exist, at a higher altitude than normal near Costa Rica’s Barva volcano. Scientists believe global warming may have contributed to the frogs relocation.