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Solenodon

The Hispaniolan Solenodon (Solenodon paradoxus), also known as the Haitian Solenodon or Agouta, is a solenodon only found on the island of Hispaniola, shared by Haiti and the Dominican Republic, and was unknown to science until 1833, when it was first described by Brandt. There was also another species present on the island, S. marcanoi, which became extinct after the initial colonization period. All solenodon species belong to the order Soricomorpha and the family Solenodontidae.

 

Contents

Description and behaviour

S. paradoxus looks much like an oversized shrew. It weighs between 0.6 and 1.0 kg, and is 28 to 33 cm long (the tail measures an extra 25 cm). It has brownish-red fur on most of its body, the underside being a lighter shade. The tail, legs, snout and eartips are hairless. The forelegs are noticeably more developed than the hind ones, but all have strong claws useful for digging.

The head is very big in relation to its body, and it has a long rostrum with tiny eyes and ears, partially hidden by the body fur. An interesting singularity is the os proboscis, a bone located on the tip of the rostrum that supports the snout cartilage. The dental formula for the species is 3/3, 1/1, 3/3, 3/3 = 40. The second lower incisor has a narrow groove (Solenodon derives from the Greek "grooved tooth") through which a venomous saliva secreted by the submaxillary gland flows, making the solenodon one of only a handful of venomous mammals.

Sexes are similar. Males have an unexposed penis and the testes are hidden deep within the abdominal cavity. Females, even though they have an irregular estrus period that is apparently unrelated to seasonal changes, may have two litters of 1-3 young per year. Usually, only 2 of the offspring (weighing 40 to 55 grams) survive, because the female only has two teats, which are found in a most unusual place: near the buttocks of the animal. The young are weaned after 75 days, though the young may sometimes remain with the parents while subsequent litters are born and raised, making it possible that up to 8 animals share the same burrow. Solenodons may fight each other on first meeting, but eventually they establish a dominance relationship and live together in captivity in relative harmony.

As well as having a venomous bite, a solenodon has glands in the armpits and in the groin which allegedly give off a goat-like smell. It readily defends itself against one of its own kind and is apparently not immune to its own venom since animals have been seen to die after fighting and sustaining minor wounds. It also probably attacks other animals savagely judging from the way a captive solenodon was reported to have attacked a young chicken and torn it to pieces with its strong claws, before eating it. In moments of excitement it may grunt like a pig or give bird-like cries, but when pursued it stays motionless and hides its head, making it easy to capture.

One reason why the solenodon was unknown to science for so long is that it is nocturnal in its habits, an effect of this being its highly developed senses of hearing, smell and touch. Also, they are not very numerous, so their influence in an ecosystem is practically nil. During day hours, they stay in their burrows, trees and hollowed-out logs or in caves, remaining hidden from view. When they do come out, they run on their toes with a stiff ungainly waddle, following an erratic almost zigzag course. The local people claim that solenodons never run in a straight line. Moreover, when a solenodon is alarmed and tries to put on speed it is as likely as not to trip over its own toes or even tumble head-over-heels.

Solenodons eat a wide variety of animals, like arthropods, worms and snails, as well as small reptiles; they may also feed on roots, fruits and foliage (however, a study found that solenodons refused all forms of vegetation). They probe the earth with their snout, and dig or rip open rotten logs with their claws. Solenodons in captivity have been seen to bathe often and to drink only when bathing. Perhaps the long snout makes any other way difficult.

 

Ecology

Considering that the solenodon is a slow moving clumsy runner, with no adaptation to predators and poor means of defense (it didn't need to evolve them given the lack of native enemies), it is accepted that once feral dog (Canis lupus familiaris) and cat (Felis silvestris catus) populations started becoming established, adding to the introduction of the Small Asian Mongoose (specifically subspecies Herpestes javanicus auropunctatus) as a means to supposedly control rats in sugar cane fields, its future began to look bleak.

The solenodon's habitat is usually wooded or brushy areas, frequently close to developed agricultural land, where they are able to dig their complex underground burrows. The loss of adequate environment, added to the predation by introduced species has contributed to making the solenodon a critically endangered animal, whose numbers have dropped dramatically during the last decades. As a matter of fact, it was considered to be practically extinct until 1907, when it was found living in the interior of the island. It was not considered to be in immediate danger early in the twentieth century. In 1966 it was found in several localities in the Dominican Republic. As of 1981, after extensive searching, it was concluded that the solenodon was 'functionally extinct' in Haiti, persisting only in the remote mountains of the south. In 1987 it was still found in both countries but was thought to be particularly threatened in Haiti. As of 1996, it could still be found in both countries. The most recent sightings in the wild (with video evidence) were during the summer of 2008, when a team of researchers from the Durrell Wildlife Conservation Trust and the Ornithological Society of Hispaniola were able to trap an individual specimen. The researchers took physical measurements and DNA from the creature before it was released back into the wild.[3]

Currently, the solenodon may only be surviving in two places in the Dominican Republic: Jaragua and Del Este National Parks. In Haiti it is reported from La Visite National Park and the Duchity region of the Massif de la Hotte[4]. Its presence in Los Haitises National Park in the Dominican Republic is inferred but unconfirmed.

 

Conservation

The Hispaniolan Solendon was identified as one of the top-10 "focal species" in 2007 by the Evolutionarily Distinct and Globally Endangered (EDGE) project.[5]

 

See also

  • Hispaniolan Hutia

 

References

  1. ^ Hutterer, Rainer (2005-11-16). Wilson, D. E., and Reeder, D. M. (eds). ed.. Mammal Species of the World (3rd edition ed.). Johns Hopkins University Press. pp. 223. ISBN 0-801-88221-4. http://www.bucknell.edu/msw3. 
  2. ^ Baillie, J. (1996). Solenodon paradoxus. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 2006-12-30.
  3. ^ "Venomous mammal caught on camera", BBC (2009-01-09). Retrieved on 9 January 2009. 
  4. ^ Samuel T. Turvey, Helen M.R. Meredith and R. Paul Scofield (2008). Continued survival of Hispaniolan solenodon Solenodon paradoxus in Haiti. Oryx, 42 , pp 611-614. doi:10.1017/S0030605308001324
  5. ^ "Protection for 'weirdest' species", BBC (2007-01-16). Retrieved on 22 May 2007. 
  • Solenodon Paradoxus, by Adam Eatroff
  • Solenodon, from the International Wildlife Encyclopedia
  • Haitian Solenodon, by Paul Massicot
  • Solenodons, from Walker's Mammals of the World Online

 

External links

  • EDGE of Existence S. paradoxus - Saving the World's most Evolutionarily Distinct and Globally Endangered (EDGE) species
 
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