|Scientific Name:||Hippopotamus madagascariensis Guldberg, 1883|
Hippopotamus guldbergi Fovet, Faure & Guérin, 2011
|Taxonomic Notes:||Two dwarfed hippopotami were described from recent fossil remains at Madagascar: Hippopotamus lemerlei and Hippopotamus madagascariensis. In a critical contribution, Stuenes (1989) thoroughly described the morphological differences between these species and provided detailed diagnoses. After Stuenes’ work (1989), the most complete account is that by Rakotovao et al. (2014), who notably documented significant intraspecific variations within both species. The origin of these species remains uncertain: they are generally seen as deriving from continental species of Hippopotamus, maybe from the extant Hippopotamus amphibius. A third extinct Madagascan species, Hippopotamus laloumena, was proposed by Faure and Guérin (1990) on limited evidence. A recent publication by Faure et al. (2010) does not add significant evidence in favor of the validity of this species, and its dissimilarity from Hippopotamus amphibius needs to be clarified. It may represent evidence for sporadic Mozambique Channel crossing by individuals of the extant large species during the Holocene, including since the European colonization of Madagascar (Burney et al. 2004).
Fovet et al. (2011) suggested that Guldberg's type specimen of H. madagscariensis actually pertains to the other small species, H. lemerlei. In 1902, C.J.F. Major re-described H. madagascariensis Gulberg, 1883 using a new Malagasy skeleton which was quite different to H. lemerlei. However, because H. madagascariensis would be no more than a replacement name for H. lemerlei, Fovet et al. (2011) proposed the new name H. guldbergi to designate the species described in 1902 by C.J.F. Major. Rakotovao et al. (2014) disagreed with Fauvet et al. (2011) on the attribution of Guldberg’s specimen to H. lemerlei, and confirmed its identification as H. madagascariensis, in line with Stuenes (1989). This debate is not closed (see Faure et al. 2015), but given that H. madagascariensis was extensively used as an available name prior to 1961 and since then (see section 11.6 of the International Code of Zoological Nomenclature), and given that the ICZN recommendations regarding the stability of taxonomic nomenclature, it is for now more cautious to continue to use H. madagascariensis and to consider H. gulbergi as its junior synonym. In any case, this debate calls for further revising the material attributed to the two dwarfed hippopotami from Madagascar, including notably their postcranial skeleton.
|Red List Category & Criteria:||Extinct ver 3.1|
Madagascan hippopotami may have survived until recent times (MacPhee and Flemming 1999), notably on the basis of local oral tradition, but are now certainly extinct.
|Previously published Red List assessments:|
|Range Description:||Hippopotamus madagascariensis is mostly known from localities of highland Madagascar (see a list of locality in Stuenes 1989). Last appearance datum of Madagascan dwarf hippopotamids remains uncertain. Most recent dates were provided through 14C dating and indicate c. 1000 AD (Dewar 1984, Burney et al. 2004). However, MacPhee and Flemming (1999) proposed it as recent on the basis of local oral tradition (Flacourt 1661) and the possible younger age of some localities. However, this may only reflect sporadic occurrence of Hippopotamus amphibius.|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This species is now extinct.|
|Habitat and Ecology:||Hippopotamus madagascariensis retains low orbits and a relatively short muzzle. Stuenes (1989) used these features to propose a more terrestrial way of life for this species than in Hippopotamus amphibius. Similarly, Stuenes (1989) indicated a cranio-mandibular morphology closer to that of Choeropsis liberiensis, the extant Pigmy Hippo from western Africa. She further noted that Hippopotamus madagascariensis exhibited teeth generally more worn than in Hippopotamus lemerlei. These characters both suggest a diet differing from that of the other Madagascan dwarf hippopotamid.|
The ecology of Hippopotamus madagascariensis may have been close to that of Mediterranean extinct dwarf hippopotamids, but further investigation of this question is required, notably on postcranial anatomy, stable isotope enamel/bone contents, and dental wear.
|Major Threat(s):||Island Dwarf Hippopotamids were probably easy prey for human hunters. This may have lead to their quick extinction in the Mediterranean (Simmons 1988). The same impact from human hunters may have been effective in at least accelerating extinction of Madagascan hippopotamids. MacPhee and Burney (1991) indicate evidence for hippopotamid butchery in south-western Madagascar dated to the 1st century AD. Gommery et al. (2011) proposed an earlier evidence of hippopotamid butchery at least dated to 1400 BC. Co-occurrence of humans and hippopotamids on Madagascar, therefore, could have lasted for a minimum of 2,000 years. How much humans have contributed to this extinction is yet to be determined.|
|Conservation Actions:||This species is now extinct.|
|Citation:||Boisserie, J.-R. 2016. Hippopotamus madagascariensis. The IUCN Red List of Threatened Species 2016: e.T40783A90128828.Downloaded on 20 February 2018.|