Solenodon Paradoxus

The Hispaniolan solenodon (''Solenodon paradoxus''), also known as the agouta, is a small, furry, shrew-like mammal endemic to the Caribbean island of Hispaniola (in the Dominican Republic and Haiti). Like other solenodons, it is a venomous, insect-eating animal that lives in burrows and is active at night. It is an elusive animal and was only first described in 1833; its numbers are stable in protected forests but it remains the focus of conservation efforts.

Its smaller sister species of the same genus, Marcano's solenodon (''S. marconoi'') became extinct after European colonization. The Hispaniolan solenodon and the rat-like Hispaniolan hutia live in the same habitats and are the only surviving mammals native to the island.

Discovery

In 1833 the Russian Academy of Sciences received a new specimen from Haiti. Puzzled by the animal, curator Johann Friedrich von Brandt named it ''Solenodon paradoxus''. (''Solenodon'' means "grooved teeth".) No more information was known other than a relation to the Cuban solenodon (''Atopogale cubana'') discovered in 1861, and it was believed to be extinct. Addison Emery Verrill and Alpheus Hyatt Verrill rediscovered the animal in the Dominican Republic in 1907, but by 1964 it was again believed extinct.

Description

The Hispaniolan solenodon resembles an oversized shrew; males and females are similar in size. Adults measure in total length, including a tail long, and weigh about on average. This makes them the largest extant members of the Soricomorpha. Although they are somewhat variable in colour, they are typically dusky brown over most of the body, with a paler underside and reddish fur on the sides of the head, throat, and upper chest. The tail, legs, snout, and eyelids are hairless.

The forelegs are noticeably more developed than the hind legs, but all have strong claws useful for digging. The head is large in relation to its body, with a long rostrum and tiny eyes and ears partially hidden by the body fur. The nostrils open to the side and the snout has about a dozen long whiskers, up to in length, with a few smaller whiskers further back on the head. A unique feature is the ''os proboscidis'', a bone extending forward from the nasal opening to support the snout cartilage; this is not found even in other solenodons.

The dental formula for the species is . The second lower incisor has a narrow tubular channel that is almost entirely enclosed, through which flows a venomous saliva secreted by the submaxillary gland. Although the exact chemical composition of the venom is unknown, injection of 0.38 to 0.55 mg of venom per gram of body mass has been shown to be fatal to mice in two to six minutes.

Hispaniolan solenodons have patches of skin rich in apocrine glands on the thighs. The secretions of these glands are used in communication between individuals.

Distribution and habitat

Hispaniolan solenodona are found only on the island of Hispaniola, in the Dominican Republic and parts of southern Haiti. Their habitat is usually undisturbed moist forest below elevation, although they are sometimes found at higher altitudes or close to developed agricultural land. There are two recognised subspecies:

* ''Solenodon paradoxus paradoxus'' – northern Dominican Republic
* ''Solenodon paradoxus woodi'' – far southern Dominican Republic and Haiti, Tiburon Peninsula

The Hispaniolan solenodon appears to have a patchy distribution. Populations are found both within and outside protected areas such as the Jaragua, Del Este and Sierra de Baoruco National Parks. In Haiti, it is reported from La Visite National Park and the Duchity region of the Massif de la Hotte. Its presence in Los Haitises National Park in the Dominican Republic is inferred, but unconfirmed.

Behavior

Hispaniolan solenodons are nocturnal; during daylight hours, they stay in their burrows, trees, hollowed-out logs or caves, remaining hidden from view. Their burrows may contain multiple chambers and tunnels and are typically inhabited by an adult pair accompanied by up to six younger family members. When they emerge into the open air, they run on the soles of their feet, following an erratic, zigzag course.

Hispaniolan solenodons feed mainly on arthropods, but will also eat worms, snails, mice and small reptiles; they may also feed on a small amount of fruit, grains, and leaf litter. They probe the earth with their snouts and dig or rip open rotten logs with their claws. They have been reported to make a number of vocalisations, including a loud defensive "chirp", an aggressive "squeal", a soft "squeak" when encountering familiar conspecifics, and a high-pitched "clic" when encountering strangers. They have also been reported to make echolocation clicks at 9 to 31 kHz.

Reproduction

Breeding occurs throughout the year, although the females are receptive only for short periods once every ten days or so. Litters of one to three young are born after a gestation period of over 84 days. Usually, only two of the offspring survive, because the female only has two teats, which are found towards the groin. The young are born blind and hairless, and weighing . They are carried about by the mother for the first two months of life, although it is unknown how long it takes for them to be fully weaned. They can live for over eleven years in captivity.

Ecology

The Hispaniolan solenodon is preyed upon by the ashy-faced owl (''Tyto glaucops'') and the Stygian owl (''Asio stygius''). Because of a lack of natural land predators, the Hispaniolan solenodon did not evolve defenses, and it is a slow, clumsy runner. Feral dog and cat populations have become established, and small Asian mongoose