The fact that new, modern-day mammal species are discovered on a fairly regular basis should most definitely not be a surprise to the average Tet Zoo reader. These are not all ‘cryptic species’ distinguishable only on the basis of DNA: many are morphologically distinctive, honest-to-goodness new animals discovered either in the field or in museum collections. And they’re not all bats and rodents: new monkeys, lemurs, sloths and hoofed mammals (peccaries, deer and bovids) have been named in recent years.
Mention ‘new mammals’ and ‘Madagascar’, and most people will assume that you’re talking about lemurs (loads of new lemurs have been named over the past decade). However, all Madagascan mammals aren’t lemurs, and the island continent has a fascinating assemblage of tenrecs, rodents, bats and carnivorans too. Madagascar’s endemic carnivorans include a motley assortment of weird, unique species (like the Fossa Cryptoprocta ferox and Falanouc Eupleres goudotii) as well as a number of bushy-tailed, often striped ‘mongooses’.
Traditionally, the Fossa, Falanouc and so on were regarded as peculiar civets (that is, they were included in Viverridae) while the Madagascan ‘mongooses’ were classified as, well, mongooses (as part of Herpestidae). Rather than representing the product of two, three, four or more separate invasion events from Africa, it now seems that all of these animals are part of a single, endemic clade (termed Eupleridae) that originated in the Oligocene and is close to mongooses proper (Yoder et al. 2003, Yoder & Goodman 2003) [diagram from Yoder et al. (2003) shown below].
Anyway, I digress somewhat. The point of this article is to announce the publication of a new, living euplerid species: Salanoia durrelli Durbin et al., 2010, discovered in the marshes around Lake Alaotra in central-eastern Madagascar. Its announcement means that two Salanoia species are now known – the other one is the poorly known Brown-tailed mongoose or Salano S. concolor, named in 1839 [a stuffed specimen is shown below: I borrowed this image from here. It has previously appeared in Nowak (1999) and Garbutt (1999)].
As is so often the case, the discovery and recognition of S. durrelli is pretty interesting. Hints of its existence have actually been in the literature for a while: in Mammals of Madagascar [shown below: an excellent book], Nick Garbutt (1999) referred to the rumoured existence of “a small carnivore in the reedbeds around [Lake Alaotra]”, the identity of which “remains a mystery” (p. 140). These reports described an animal similar to the Brown-tailed mongoose. During a 2004 wildlife census, members of the Durrell Wildlife Conservation Trust (DWCT) observed a small carnivoran swimming in Lake Alaotra. They captured it, photographed it, and released it (I’d love to see these photos: would have been nice to use them here). While it looked like a Brown-tailed mongoose, it differed in colour (being grizzled yellowish brown: the Brown-tailed mongoose is usually reddish brown).
The DWCT researchers were already familiar with Garbutt’s ‘mystery carnivore’ of the Lake Alaotra marshes and were confident that their swimming mongoose was one and the same thing. In 2005, they made a special effort to discovery the identity of this animal. And they succeeded, capturing two individuals – one male and one female – in traps set on floating vegetation at Andreba, at the eastern edge of the Alaotra wetlands. The female was euthanised and now serves as the holotype for the species (reminder: a species doesn’t get conservation status until it officially exists, and ‘existence’ is best demonstrated by the procuring of a specimen).
Molecular analysis revealed that the genetic distance between the Alaotra mongoose and the Brown-tailed mongoose is small (less than that observed within some other euplerid taxa uncontroversially regarded as monotypic species). In fact, the authors state that – if they were relying on genetic data alone – separate species status might not be awarded to the new animal. However, it isn’t clear that low levels of genetic variation necessarily disprove species status for any given population: indeed, some mammals universally regarded as ‘good’ species (like Mule deer Odocoileus hemionus and White-tailed deer O. virginianus) are extremely close genetically. And it’s increasingly recognised that we can’t rely on one line of evidence alone anymore: molecular data needs to be taken into account when examining possible new species, but so does morphological and behavioural data, and it is – hopefully – well known by now that there is no clear, objective way of determining ‘how distinct’ a population has to be before it can be recognised as one of those entities that we term ‘species’ anyway.
Statistical analyses of morphology showed the Alaotra mongoose to be well separated from Brown-tailed mongooses in skull and tooth proportions, and in the size and shape of its feet and foot pads. Compared to the Brown-tailed mongoose, the Alaotra animal has a paler, more olivaceous, grizzled pelage, it may be slightly smaller, it has broader feet with larger palmar and plantar pads, a broader muzzle, and a more robust lower jaw and dentition [image used at very top, from Durbin et al. (2010), compares the skulls and lower jaws of the two Salanoia species]. Many details of the dentition are distinctive: in comparison with the Brown-tailed mongoose, the surface area of the first upper molar is large in the Alaotra animal, its second upper molar is large compared to its first upper molar, its fourth upper premolar is broader, its canine is more robust, and so on.
In view of these obvious morphological differences, it seems appropriate to recognise the Alaotra mongoose as a new species. The name Salanoia durrelli of course honours Gerald Durrell (1925-1995), “inspirational writer and conservationist” (Durbin et al. 2010, p. 6) [photo of Durrell used at very top from here]. This is far from the first animal to be named after Durrell: Durrell’s night gecko Nactus durrelli (originally named as a subspecies), endemic to Round Island, was described in 1994, Durrell’s tadpole goby Benthophilus durrelli was described from the Don River Basin (in Ukraine) in 2004, the new Russian cossoid moth Kotchevnik durrelli was described in 2004, the Sri Lankan Durrell’s freshwater crab Ceylonthelphusa durrelli was named in 2005, and the new Ecuadorian glassfrog Centrolene durrellorum was named after both Gerald and Lee Durrell in 2005.
While virtually nothing is known of the natural history of S. durrelli, its association with a marsh habitat and its relatively robust jaws and dentition suggest that it preys on crustaceans and molluscs, and perhaps also on amphibians, fish and so on. Durbin et al. (2010) note that S. durrelli may be a Madagascan equivalent of the African Marsh mongoose Atilax paludinosus: a wetland species [shown above; photo © Trevor Hardaker, from here] that also uses floating mats of vegetation for feeding and resting, and also has relatively robust jaws and teeth that help it to eat molluscs, crustaceans and small vertebrates. The Brown-tailed mongoose, in contrast, is more insectivorous, though it does also feed on frogs, small reptiles and rodents.
It goes without saying that the Alaotra mongoose is deserving of immediate conservation priority. Lake Alaotra – a unique habitat, inhabited by an endemic lemur (the only primate that spends most or all of its life living above water) as well as highly endangered birds – has been ruined by introduced fish and plants, overfishing, and by acidification and silting-up resulting from local deforestation. The Alaotra grebe Tachybaptus rufolavatus hasn’t been observed since the late 1980s and recent assessments have led to the conclusion that it’s now extinct. Durbin et al. (2010) speculate that rats, dogs, cats and civets introduced to the Alaotra area may well have had an impact on the ecology of the new mongoose: like the other endemic species, it’s likely to be threatened and declining, but more data is urgently needed.
For more on recently discovered living mammal species, see…
- Multiple new species of large, living mammal (part I)
- Tetrapods of 2007 (happy birthday Tet Zoo part II)
- Chinese black rhinos and deinotheres, giant sengis, and yet more new lemurs
- New, obscure, and nearly extinct rodents of South America, and… when fossils come alive
- Giant furry pets of the Incas
- Over 400 new mammal species have been named since 1993
- The newest whales
Lake Alaotra and its endangered birds were previously discussed in…
And, for more on euplerids and other cat-branch carnivorans, see…
- Belated welcome to a ‘new’ clouded leopard.. named in 1823
- Mystery of the Erongo carcass
- Peter Hocking’s big cats: where are you now?
- Homage to The Velvet Claw (part I)
- Homage to The Velvet Claw (part II)
- The Pogeyan, a new mystery cat
- The Hayling Island Jungle cat
- ‘Revising’ the Siberian tiger
Refs – –
Durbin, J., Funk, S. M., Hawkins, F., Hills, D. M., Jenkins. P. D., Moncrieff, C. B., Ralainasolo, F. B. 2010. Investigations into the status of a new taxon of Salanoia (Mammalia: Carnivora: Eupleridae) from the marshes of Lac Alaotra, Madagascar. Systematics and Biodiversity 10.1080/14772001003756751
Garbutt, N. 1999. Mammals of Madagascar. Pica Press, Mountfield.
Nowak, R. M. 1999. Walker’s Mammals of the World, Sixth Edition. The Johns Hopkins University Press (Baltimore and London)
Yoder AD, Burns MM, Zehr S, Delefosse T, Veron G, Goodman SM, & Flynn JJ (2003). Single origin of Malagasy Carnivora from an African ancestor. Nature, 421 (6924), 734-7 PMID: 12610623
– . & Flynn, J. J. 2003. Origin of Malagasy Carnivora. In Goodman, S. M. & Benstead, J. P. (eds) The Natural History of Madagascar. University of Chicago Press, Chicago, pp. 1253-1256.