Wednesday, 8 October 2014

Book Review: Extinct Madagascar: Picturing the Island's Past

Details: Extinct Madagascar: Picturing the Islands Past by Steven M.Goodman and William L.Jungers, plates by Velizar Simeonovski. Available from Amazon.

Red Bellied Lemur
I thought I would add an occasional post for book reviews that might be of interest to readers, so I am starting with this one. It is an overview of the recently extinct fauna of Madagascar, of which there is sadly far too much, as anyone who is interested in the current ecological disaster on the island will be well aware. Part 1 covers the geological history, colonisation history (both animals and humans), and the vegetational types on the island. Part 2 is structured around a series of colour plates of sites where subfossil remains of the fauna have been located, accompanied by descriptions of the animals illustrated and what the various sites mean for the complex history of the island over the 2000 or so years since human beings colonised the island.

The most important take away for me is that it is this is the first book I know to give a reasonable background picture of what the island’s fauna was like before the advent of humans. In the various plates you will find not just the living animals found today, but the even weirder relatives that did not make it. Among these will be of course a large selection of lemurs, including the seriously odd-looking sloth lemurs in the Paleopropithecidae, a totally extinct group that, yes, behaved like the tree sloths of South America. Unexpectedly, this group also included the largest known lemur, and one of the largest primates ever, Archaeoindris, known only from a few bones at a single site but which had an estimated body mass of 200kg, close to that of an adult silverback gorilla. Archaeoindris seems to have been the primate equivalent of a ground sloth, and judging by how few bones of it have been found compared to other Madagascan animals, may have been on the edge of extinction as a result of drastic climate and environmental change even before humans arrived. Another key group of large lemurs were the koala-lemurs, Megaladapis – large bodied folivores with grasping hands that were as big as a small sheep.

Madagscar’s fauna is a lot more than the primates that feature so heavily in zoo collections, and one of the islands major herbivores would have been various species of Aldabrachelys giant tortoises. A single species of these actually survives today in the form of the Aldabra Giant Tortoise, which means that potentially it could be used in ecological restoration in the appropriate habitats on Madagascar. Other herbivores on the island included three species of hippo, one slightly smaller than the modern mainland African river hippo, and another which seems to have been closer to the living Pygmy Hippo of West Africa. Predators included Cryptoprocta spelea, a larger version of the living fossa C.ferox, and the crocodilian Voay robustus, a relative of the living African Dwarf Crocodile Osteolaemus tetraspis but which grew to 5m long. Most importantly among the charismatic megafauna were the elephant birds, the gigantic Aepyornis and the slightly smaller (but still ostrich-sized) Muellerornis. How many species of these existed are unclear – going by recent discoveries in New Zealand moa male and female elephant birds may have been of very different sizes. Unfortunately the book does not manage to include recent discoveries of the ancestry of elephant birds, which turn out to be related to kiwis of all things. Less well known, but still an important element of the fauna, were predatory birds such as the Malagasy Crowned Eagle Staphanoaetus mahery. Its mainland relative S.coronatus is a key predator of monkeys, and the Madagascan version was certainly an equally significant predator of lemurs.

For students of the current situation on Madagascar one of the themes is how both vegetation types on the island have changed as a result of both human induced farming practises, especially deforestation and setting fires, and natural climate change have altered both what we see today and where the animals are found. It is plain that many species with restricted ranges today were once found over far wider areas, and the pre-human history of the island is one of shifting ecosystems across the island changing as rainfall fluctuated in the Pleistocene. Sadly, there are few if any fossil sites on Madagascar between the Cretaceous and the last few thousand years, but if any are found they will be of great interest in untangling the history of the island’s animals and plants.

For zoo designers, this book should give plenty of ideas for new exhibits. Animal displays shy away from mixing animals from different parts of the world, but for a Madagascan exhibit this might actually be a good way of showing what used to be there. What about a mixed lemur/ giant tortoise display, or one containing one of the available ratites? Hippos are not the sort of animals which are good in mixed exhibits, but with careful design one could tell the story of the extinct Malagasy hippos as well as that of the living, but highly endangered, Pygmy Hippo.

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