Biology: a reader reports from Mauritius

July 1, 2011 • 6:07 am

Mauritius is a small volcanic island of about 2000 square kilometers, located 900 km east of Madagascar.   Because of its origin as an oceanic island that formed bereft of any life, it’s home to many rare and endemic species (some of which, like the dodo, are extinct).

When I asked readers to send photos of their biological research,  Dr. Dennis Hansen, who is based at the Institute of Evolutionary Biology and Environmental Studies of the University of Zurich, came though in spades.   He sent well over a dozen photos of his work on Mauritius, all of which were gorgeous. I’ll highlight some of them today and the rest tomorrow.  First, a map:

Then a view, described by Dennis thus:

 A morning view from the most famous mountain in Mauritius, Le Morne. It is like a miniature South American Tepuis; we went there by helicopter to study the national flower of Mauritius, whose last populations survives on the vertical cliffs of the mountain. Up there, looking across to the southwestern Black River Gorge mountains, one can almost forget that the island also houses a destructive human population of 1.3 million on a mere 1865 square kilometers. Almost.

The first involves one of the world’s rarest birds: the Echo parakeet (also called the “Mauritius parakeet”), Psittacula echo, found on the southwest part of the island. If you’ve read Last Chance to See, you’ll know about the extraordinary effort expended in saving this gorgeous bird. Once down to a mere 9 individuals, and about to become an ex-parakeet, captive breeding has brought the population back to about 290 individuals. It’s one of the great success stories of conservation.  Here are a couple of Dennis’s pictures; they are all of the same individual, named “Alpha” (note the band):

Some of these birds are so tame that they’ll do this:

Dennis described Alpha as “a sadly slightly too tame, hand-reared Echo parakeet. He hung around our field station in the rainforest & loved stealing my morning coffee.”  When I asked him if Alpha did this often, and if he really liked the coffee, Dennis replied, “Yes, Alpha the Echo had a beak for coffee. I never let him drink it on purpose, and tried to keep him off my cup (easier said than done). But just this once I thought I’d want a photo of him in flagrante delicto.”

There’s a good description of how work is going on this species at the Odyssey website.  Here are two photographs (by Genevieve and Chris Johnson, respectively) of a hand-reared Echo parakeet abandoned by its parents. Note the full crop in the first photo!

Here’s a chick being weighed.

The next species is endemic to the Seychelles, an archipelago whose location is on the map above. (By the way, both Mauritius and the Seychelles have endemic species of Drosophila in the D. melanogaster subgroup, D. mauritiana and D. sechellia respectively. I’ve spent years working on these species, and have published quite a bit on them, but, sadly, I’ve never had the privilege of visiting either island).

If you thought that the giant land tortoise was endemic only to the Galápagos, think again.  The Aldabra atoll (a series of island in the Seychelles) has its own (smaller) species of giant tortoise, Aldabrachelys (or Geochelone) gigantea.  And while there about 19,000 individuals in toto on the Galápagos, there are more than 150,000 individuals of the Aldabra species.   Some of them have been transplanted to Mauritius to replace its extinct endemic tortoise, and that’s where these photos come from.  First, a tortoise eating a fruit:

Look at those jaws!  Dennis reports that this, however, is a yawn:

And of course all of those tortoises have to come from somewhere.   Dennis describes the photo below:

Two giant Aldabra tortoises having fun at the La Vanille Tortoise Reserve in Mauritius (where we do a lot of our feeding experiments). You can’t spend more than 30 minutes around these behemoths before you hear/see it. Cracks me up every time.

Note the huge disparity in size between male and female (also seen in the video below):

Dennis also sent a link to a 26-second video of mating Aldabra tortoises (below). You’ll find it sad, touching, and hilarious.  I still wonder how insemination can really occur this way!

Tomorrow: gorgeous geckos that pollinate flowers.

Oh, and heeeere’s Dennis:

42 thoughts on “Biology: a reader reports from Mauritius

  1. Great photos – well done Dennis.

    About the Aldabran tortoise – Wikipedia says “In the 1960s, the British considered allowing the United States to use the island as home for a military air base. After an international protest by ecologists, however, the military plans were abandoned and the wildlife habitat instead received full protection”. I well remember that – after watching a TV programme I wrote to my MP about it (must have been 7 or 8), so it was the first awareness I had of human destructiveness of the natural world and an introduction to the importance of conservation. Glad they made it.

    1. Yes – the so-called ‘Aldabra Affair’ – the fight was spearheaded by David Stoddart, and made its way into Nature, Science etc. Instead, the powers that be decided to deport people from Diego Garcia, and build the naval/air base there. And thanks, on behalf of the tortoises there, that you did your part back then, too, Dominic!

  2. Cracks me up every time.

    Indeed, few things in nature are as intrinsically funny than tortoises doin’ it.
    Living in a box is all well and good until it’s time to hook up.

  3. Great photos. There was also an echo parakeet, now extinct, on Reunion; it was last recorded in 1732. There are a couple of nice books on the fauna of the Mascarene Islands (Reunion, Mauritius, Rodrigues): Cheke, A. and J. Hume. 2008. Lost Land of the Dodo: An Ecological History of Mauritius, Réunion & Rodrigues. Yale University Press, New Haven, Conn. and Diamond, A.W., ed. 1987. Studies of Mascarene Island Birds. Cambridge University Press, Cambridge. The former has numerous paintings of life reconstructions (based on skins, skeletons, and early descriptions) of the many recently extinct species of these islands (I wish they’d reduced them less in printing).

      1. The parakeets/parrots of the Western Indian Ocean islands are a fascinating topic. Most recently summarised & ‘sorted out’ by Julian Hume (Hume, J. P. 2007. Reappraisal of the parrots (Aves: Psittacidae) from the Mascarene Islands, with comments on their ecology, morphology, and affinities. Zootaxa 1513:1-76).
        I wish I had a time machine, so I could go see the raven-parrot – a huge (maybe the largest recent parrot species?) bird with a beak to match. Even if I’d probably spend the time hugging the giant skinks and the tortoises instead.

  4. human population of 1.3 million on a mere 1865 square kilometers.

    This sort of thing is why I was so astonished to find that there are just 6.2M people in all of Ireland (~4.7x the number of people on ~45x the land mass; I’d expected more like 20M there).

    1. Not surprising when you consider the history of the last 200 years. To simplify – Absentee British landlords and short tenancy agreements meant that anyone who improved his land had the rent hoiked when it was renewed. People responded as the poor always have – had lots of children. The staple became the potato that was about the only thing they relied on so when blight came disaster resulted. Large numbers were forced off the land – really their land – the only real option for many was exile to Australia or the US etc. Consequently a huge percentage have left over the years since. Of course it is now attractive for immigrants from East Europe etc. My mother’s mother’s mother’s mother’s mother was Irish – a Kennedy of some sort – and would have moved to London ca. 1810/20 ish. The UK population in contrast is 10 times that and went up 500,000 in the last year! Population pressure is something few people want to address – yet in a world of finite growth, how can we expect continued growth? Where does it end?

      1. I wish the politicians round here would address these issues,(Australia) it’s all very well looking at a map and thinking “We need more people” but it’s practically all desert. What are they all going to drink, or wash in?

        1. What about this statistic –
          “The UK has less available water per person than most other European countries. London is drier than Istanbul, and the South East of England has less water available per person than the Sudan and Syria.”

  5. For a while, some years ago my house was home to a couple of good size (shell about 15″ long) leopard tortoises. We became accustomed to bouts of loud clunking on the hard floors when the mood struck them.

    While it seemed improbable that anything could come of those awkward trysts, we did get viable eggs.

  6. Great photos Dennis. And a crackbv video too! Is tfat a Pandanus fruit you are holding? Wot no Drosophila mauritiana?

    1. Thanks Matt; the video is not mine – just a link to one of the many tortoise-sex videos available on youtube. And yes, it’s a Pandanus, but from the Seychelles (I think it’s P. hornei). And sorry for not having taken a photo of Drosophila mauritiana yet; one of the great gaps in my library! The flies are everywhere when the fruits of the invasive guava litter the forest floor.

  7. I still wonder how insemination can really occur this way!

    Where there’s a willy there’s way?

    1. You must be joking. First of all, this guy is on Mauritius and works with these birds. The Alexandrine Parakeet does not occur on Mauritius where these pictures were taken. Finally, your parakeet has red patches on its wing feathers and the one above, the echo parakeet, doesn’t. Why on earth would you suggest such a thing?

      1. Hi Jerry.

        It just seemed odd to me that most of the pics of the Mauritius Parakeet I found showed it with a blue beak. Also I found the pics on your post very similar to those of these parakeets I came across with in Belgium.

        There was no ill intent in my comment, but I think that now I will want to get more into the Mauritius Parakeet just to make sure there’s no mistake with the pics.

        I will email you if there is a true mistake (which I doubt). I’m just learning, not being a scientist and all 🙂


        1. The Mauritius bird has a smaller beak among other things. Perhaps the similar coloration betrays the ancestry of the Mauritian bird? I wonder if that molecular work has been done?

          One thing I wondered if Dennis can tell us – how common is it to find the bones of the Dodo?

          1. Quite common, if you dig in the right places! But not as common as bones of giant tortoises 😉
            A good paper about recent diggings:
            Rijsdijk et al, 2009. Mid-Holocene vertebrate bone Concentration-Lagerstatte on oceanic island Mauritius provides a window into the ecosystem of the dodo (Raphus cucullatus). Quaternary Science Reviews 28:14-24.

            Also, as late as a few years ago, two tourists found a whole dodo-skeleton in a lava-tube.

      2. Also, there are lot of Alexandrine pics showing them without the red patches, yet with the exact same facial coloration and general body shape, size and color as the ones presented here. I have probably been mistaken, but I would say it was an honnest mistake. The Mauritius pics I found with google mostly look like Alexender, which can be unsetling to the layman.

  8. “ex-parakeet” immediately made me think of “This is an ex-parrot!”

    “Norwegian Blue! Lovely plumage!”

    On a positive note, excellent photos. Thank you.

  9. Thanks for positive comments, all! (& thanks for showing the photos, Jerry – although I never did send you one of me, because i always look weird in photos, so not thanks for that! ;-)). But yes, it *is* an echo parakett 😉 -although there is another species on the island; the introduced ringnecked parakeet, Psittacula krameri. You can tell them apart easily on voice and ‘stockiness’ of the body. I never worked directly with these birds, though — I am a pollination/seed dispersal biologist, and these parrots are mainly seed predators.
    I did spend many field seasons living at the main field station in the remnant rain forest in Mauritius, where one can now see flocks of 30-40 echos flying around. A testament to the hard work of one of the most amazing teams of field biologists I have had the pleasure of working alongside.
    Right, just back from an evening of drinking (slightly) too many beers while happily discussing upcoming work on Aldabra with a group of fellow nerds – g’nite all.

  10. A very gorgeous parrot, the tortoise not so much. ;-)It may be just the photos but the Echo looks like it has much brighter green plumage than the Alexandrine to me, as well as no shoulder patch. How on god’s green earth do tortoises get to these islands? Were their ancestors turtles? Can a tortoise swim?

    1. From the Wikipedia article:

      They are also excellent swimmers, being naturally buoyant. This factor has allowed the spread and eventual speciation of many kinds of related tortoises across the Indian Ocean.

    2. That is actually quite a handsome tortoise, as tortoises go.

      I take it that we’re going to see Phelsuma tomorrow? Great!

      1. Finally someone with good taste 🙂 And I think Jerry might have a Phelsuma photo or two. They are truly gorgeous animals – with fantastic behaviours to match.

  11. Your blog is like being on a world tour as well as a animal tour. I will never remember all the genus names of these creatures but I will have fun trying.

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