Readers’ wildlife photographs

September 4, 2015 • 7:45 am

Karen Bartelt previously sent us some Galápagos photos, and here’s another batch. The first one shows the remarkable tameness of the animals, which of course was noted by Darwin. The reason is almost certainly because of the lack of predators on the archipelago, for animals like snakes and mammals (except for seals and sea lions) simply couldn’t get there. (Yes, there’s a hawk, but that’s just one predator.)

The tameness means that there’s a tradeoff to being watchful and skittish: doing so means you can’t forage or look for mates as diligently because you’re always watching for predators. Since that selection pressure doesn’t exist on the archipelago, the animals have evolved tameness. Now it’s possible that the tameness is learned rather than evolved, but that could be checked by rearing animals in the lab so they’re never exposed to the environment, and seeing if they remain extraordinarily tamer than controls, also hand-reared but from islands with predators. I’m not sure that that’s actually been done for animals like Galápagos finches, as it’s illegal to take them off the islands. If readers know of such experiments with animals from other oceanic islands, let me know.

Here are Karen’s notes:

Cactus ground finches (Geospiza scandens) in my husband’s hand at the home of Gil de Roy in Santa Cruz:
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Pale iguana (Conolophus pallidus), Santa Fe:

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A “regular” land iguana (Conolophus subcristatus), South Plaza:

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Large cactus ground finch (Geospiza conirostris), Espanola:

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Medium tree finch (Camarhynchus pauper), Floreana:

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Small Volcan Alcedo tortoise (Geochelone vandenburgi), near Urbina Bay:

IMG_3054IsaUB

Red-footed boobies (Sula sula websterii), Genovesa Island:

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6 thoughts on “Readers’ wildlife photographs”

  2. Excellent. I will never tire of Galapagos photos.
    I did not know about the pale iguana, and so learning something is extra great. Thank you.

  4. Now it’s possible that the tameness is learned rather than evolved, but that could be checked by rearing animals in the lab so they’re never exposed to the environment, and seeing if they remain extraordinarily tamer than controls, also hand-reared but from islands with predators.

    Tameness is definitely a learned trait in cats. Take a kitten from a feral cat’s litter and raise it in the home and it’ll be a typical housecat whilst its twin raised by its mother on the street won’t go near humans.

    b&

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