Islands make animals tamer

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When Charles Darwin visited the Galapagos Islands, he noted that many of its animal inhabitants were so unafraid of people that “a gun is here almost superfluous”. He swatted birds with his hat, pulled the tails of iguanas and sat on giant tortoises.

These antics fuelled his famous idea that animals become tame when they live on remote, predator-free islands. Now, William Cooper Jr of Indiana University–Purdue University in Fort Wayne has tested Darwin's hypothesis on 66 species of lizards from around the world and found that island dwellers tended to be more docile than their continental relatives — the strongest evidence yet for this classic idea. The results are published this week in Proceedings of the Royal Society B.

Several studies and unpublished reports have shown that particular species are more approachable on islands where there are fewer predators, or quicker to flee on islands that contain introduced hunters such as feral cats. But despite this largely anecdotal evidence for island tameness, “no one has ever established that it’s a general phenomenon in any group”, says Cooper. “We showed that for a large prey group — lizards — there really is a significant decline in wariness on islands.”

Taming of the few

“Island tameness is an old idea, but there have been few tests of it,” says Dan Blumstein, a behavioural biologist at the University of California, Los Angeles. “This is a needed paper that convincingly shows some of the drivers of island tameness in lizards.”

Written By: Ed Yong
continue to source article at nature.com

7 COMMENTS

  1. ” But despite this largely anecdotal evidence for island tameness, “no one has ever established that it’s a general phenomenon in any group”, says Cooper. “

    Huh?!?

    And I thought this was established science! Perhaps my admiration for Charles Robert Darwin advanced my belief ahead of the evidence!

    Of course with no predatory selective pressure the nonchalant organism could survive and successfully reproduce.

    • In reply to #2 by squeegee:

      Brings to mind the Dodo and the Moa …. walk right up and grab a drumstick folks! I wonder if the first peoples out of Africa encountered game with no fear of humans?

      Hi Squeegee. Jared Diamond’s ‘The Third Chimpanzee’ discusses this situation in detail with lots of specific examples around the planet over 50000 years…. Mac.

      • Many thanks for that info Cd, looking forward to reading it! In reply to #3 by CdnMacAtheist:

        In reply to #2 by squeegee:

        Brings to mind the Dodo and the Moa …. walk right up and grab a drumstick folks! I wonder if the first peoples out of Africa encountered game with no fear of humans?

        Hi Squeegee. Jared Diamond’s ‘The Third Chimpanzee’ discusses this situation in detail with lots of s…

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