The Last Survivors


Hispaniolan hutia

The arboreal skills of the Hispaniolan hutia (photo: Jorge Brocca)

The arboreal skills of the Hispaniolan hutia (photo: Jorge Brocca)

The Hispaniolan hutia (Plagiodontia aedium) is the only surviving native rodent on Hispaniola. It has an adult body mass of 1.2-1.3 kg, and resembles a muskrat or a giant guinea pig with a scaly, naked tail. In common with many other island species that have evolved in the absence of native mammalian predators, Hispaniolan hutias exhibit a slow life history strategy, taking over two years to reach sexual maturity and giving birth to only one or two young at a time. However, they have a wide diet that includes a range of different leaves, shoots, bark and roots. They also seem to be behaviourally flexible, being reported to live in either tree cavities or crevices in limestone depending on the availability of forest cover. The species is a member of the Capromyidae, a hystricognath rodent family restricted to the islands of the West Indies; other living hutias are still found in Cuba, Jamaica and the Bahamas. Genetic studies suggest that Plagiodontia is the oldest living lineage within the Capromyidae, and may have diverged from other hutias about 20 million years ago. At least two larger-bodied species of Plagiodontia (P. araeum and P. ipnaeum) also occurred on Hispaniola until human arrival in the Caribbean region, and may have survived until European arrival around 500 years ago, but both of these species are now extinct.

Plagiodontia aedium was described in 1836 by the famous French anatomist Georges Cuvier, the first scientist to demonstrate that extinction was a real process. The name ‘aedium’ refers to the local nineteenth century Haitian name for the species, ‘Rat-Cayes’ or ‘house rat’, so-called because hutias were apparently noted for frequenting human habitations. Cuvier also recorded that the species was very good to eat, and that already by the early nineteenth century it had become very rare – making it one of the first species ever to be recognised as being in danger of extinction. No other hutia specimens were reported from Hispaniola for most of the nineteenth and early twentieth centuries, and the species was considered to be possibly extinct until its rediscovery in the Samaná Bay region of the Dominican Republic by Dr W. L. Abbott, a collector for the Smithsonian Institution, in 1923. However, Abbott also had major concerns about the continued survival of the species. He said:

 

The illustration of Plagiodontia aedium published in Cuvier’s original description of the species in 1836.

The illustration of Plagiodontia aedium published in Cuvier’s original description of the species in 1836.

“An old man, stimulated by the offer of $5 a piece, brought me 11. He caught them with dogs in hollow trees down near a lagoon near sea shore. Females all pregnant, one fetus at a time. It was miserable at Guarabo, mosquitoes awful, mud and rain most of the time, so we came back here. Another brought me two Hutias last night from about 3 miles west of Jovero. The Hutias must still be abundant in some districts. The Dominicans don’t seem to eat them but some dogs hunt them. They can climb to some extent. They are doomed with the coming of the mongoose. Their slow breeding will probably help their extinction.”

Confusion about morphological differences shown by Cuvier’s hutia specimen, fossil hutia remains collected in the early twentieth century, and the animals from Samaná Bay led to the hypothesis that there might be a second living species of Hispaniolan hutia, which was formally described as Plagiodontia hylaeum. Although subsequent research has suggested that there are probably no consistent morphological differences between living hutia populations on Hispaniola, the identity and relationship of living Plagiodontia populations remains unclear. Little field research has subsequently been conducted on Plagiodontia in either the Dominican Republic or Haiti, and although hutias are known to persist in both countries, their continued distribution and status are extremely poorly understood (see map below for the current estimate of the species’ range). It qualifies as Endangered on the IUCN Red List of Threatened Species.

Hispaniolan hutia range map

Hispaniolan hutia range map

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Key references

Anderson S (1965) Conspecificity of Plagiodontia aedium and P. hylaeum (Rodentia). Proceedings of the Biological Society of Washington 78: 95-98.

Johnson DH (1948) A rediscovered Haitian rodent, Plagiodontia aedium, with a synopsis of related species. Proceedings of the Biological Society of Washington 61: 69-76.

Miller GS Jr (1928) The rodents of the genus Plagiodontia. Proceedings of the United States National Museum 72: 1-8.

Sullivan CP (1983) Status and distribution of Plagiodontia aedium in the Dominican Republic. Unpublished M.Sc. thesis, University of Florida.

Woods CA (1981) Last endemic mammals in Hispaniola. Oryx 16: 146-152.

Woods CA, Ottenwalder JA (1992) The natural history of southern Haiti. Florida Museum of Natural History, Gainesville, FL.

Woods CA, Ottenwalder JA, Oliver WLR (1985) Lost mammals of the Greater Antilles: the summarised findings of a ten weeks field survey in the Dominican Republic, Haiti and Puerto Rico. Dodo 22: 23-42.



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