Giant tortoises FTW

February 12, 2014 • 3:10 pm

What better way to conclude Darwin Day than with some pictures of giant tortoises—not from the Galápagos, mind you, but an independently evolved case of island gigantism on Aldrabra in the Indian Ocean. The pictures come from biologist and reader Dennis Hansen from the Institute of Evolutionary Biology and Environmental Studies in Zurich. His explanation:

I’m currently stuck on Mahe Island, Seychelles, waiting for a nasty storm to clear so we can fly a tiny plane to Assumption & get over to Aldabra Atoll. It being Darwin Day, I thought I would share some non-avian wildlife photos with you, of giant Aldabra tortoises. Although not as morphologically diverse as their relatives on Galapagos, they nevertheless vary substantially in shell shape/size (even though the atoll last emerged from the sea only around 80,000 years ago, the most recent of many ‘versions’ of Aldabra). See attached for a selection of black & white photos (all done from digital colour images in Photoshop, using the Silver Efex Pro plugin from Nik Software). While I like giant tortoise photos in colour, I love the way black & white brings out the graphical qualities, and how it seems to underscore just how large they are.

If you like giant tortoises, art, islands, rewilding, or combinations thereof, you can also check out our art & science project.

Cheers & happy Darwin Day!

You can read more about this species (Aldabrachelys gigantea) here.





18 thoughts on “Giant tortoises FTW

  1. Extraordinary animals, and great photos! Thank you for sharing them with us. I have only ever seen them in zoos, seeing them in their natural habitat must be quite an experience.

    And as a fan of Sebastiao Salgado’s work, I fully agree and think that these pictures look particularly good in B&W. In fact, they wouldn’t look out of place in his latest “Génesis” project, especially the first two. Thank you.

    1. Wow, high praise indeed! Thank you for your kind words. I am a big fan of Salgado. I am getting very excited to soon be back on their atoll (fingers crossed).

  2. Very well done — great tonality, and the expressions and composition all. And the one with the crab is a great example of what Henri Cartier-Bresson called the “decisive moment.”



  3. Awww they are so cute! Look at their cute little faces! I want to scratch the tops of their heads.

    I love the title of this – where else would you see “FTW” next to “Giant tortoises?”.

    1. I patted a giant tortoise at Melbourne zoo a couple of weeks ago, amazing shell texture, very rough. I didn’t have the nerve to scratch its head though.

  4. I’ve seen giant tortoises on Alphonse Island, Seychelles. Here’s a photo of one eating fruit that had fallen from a tree.

    I watched a pair mating. The male was making very loud noises. Very loud!

    I wondered how they travelled between the islands. One of the fishing guides told me that they can swim and they’ve been seen in the ocean.

    While I’m at it, here’s a photo of a Giant Trevally I caught in the Seychelles. 🙂

    1. Cool, Stephen! Yes, they do like to eat their ‘fruit a day’, if they can find some. We’re currently studying their role as seed dispersers on Aldabra (together with the other frugivores there: dove, blue pigeon, bulbul, white-eye, gecko, fruitbat & others. One of the extremely few island ecosystems worldwide (if not the only one?) to have a more or less full set of frugivores still extant.

      We’re also studying the breeding bellows the males make — this is the only time giant tortoises make any sound, apart from hissing when pulling their heads in. …or at least the only sound that we can hear. Looking into the possibility of infrasound, too.

      Giant tortoises are very good ocean crossers – they can float for months. This is how they got to so many islands in the first place (now only to be found on Galapagos & Aldabra).

      1. I wonder what would persuade a giant tortoise to take to the sea, with no clue where he or she would end up. Maybe they get swept out while feeding near the surf? It seems really weird and remarkable to me that huge, ponderous reptiles could colonize remote islands.

        1. One explanation I can offer is this one: on Aldabra, the giants often feed at the edge of mangrove forests, hoovering up wilted leaves left behind by the receding tide, or crashing over small saplings to eat the leaves (much like elephants in Africa/Asia do with much larger trees).

          I have several times observed how they get so caught up in this that they don’t realise when the water comes rushing back in to the lagoon. Then they sometimes have to make their way back to the ‘mainland’by wading/bobbing through the rising tide.

          It is a small step from there to imagine it being caught in the tide & rushed back out to sea when the lagoon empties next time. Indeed, last year during a large reef-mapping exercise, the marine scientists encountered a female tortoise floating several hundred metres away from the coast on the outside of the atoll. Now imagine if she’d been with eggs & drifted off to a nearby (or far away!) island. Ta-daa! New tortoise population 🙂

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