As late as the 1960's, Solenodon paradoxus was not considered to be in any danger of extinction. However, in more recent years, the decline of suitable forest habitat through deforestation, an increase of human activity in their habitat, and the introduction of new predators (domesticated canines and felines) have contributed to the enormous decrease this species' numbers.
US Federal List: endangered
CITES: no special status
IUCN Red List of Threatened Species: endangered
Before the European colonization of Hispanolia, which has resulted in the introduction of several predators of solenodons the island, Solenodon paradoxus was one of the dominant predators on Hispaniola. In fact, to this day, it lacks any truly natural predators and does not possess many anti-predator adaptations. Solenodon paradoxus is described as a "slow mover" and a "clumsy runner with no agility in avoiding enemies and a poor means of defense" (International Wildlife Encyclopedia, 1974). It has been observed sitting still, with its head hidden, while predators are in pursuit.
Known Predators:
Solenodon paradoxus looks much like a shrew. However, it is considerably larger. A black to reddish-brown pelage covers the majority of the body, with the exception of the tail, feet, nose, and tips of the ears. The forelimbs are considerably more developed than the hindlegs, but all limbs have claws presumably for digging.
Its heads is large in proportion to its body and the rostrum is elongated. A defining characteristic of Solenodon paradoxus is the os proboscis, a bone (which supports a long cartilaginous snout) located on the tip of the rostrum. This species' dental formula is 3/3, 1/1, 3/3, 3/3 = 40. The second lower incisor has a groove from which a venom is secreted from a mandibular gland.
Males of this species have an unexposed penis and testes residing deep within the abdominal cavity.
Range mass: 600 to 1000 g.
Range length: 0.28 to 0.33 m.
Average length: 0.31 m.
Other Physical Features: endothermic ; bilateral symmetry
There is very little information concerning the lifespan/longevity of Solenodon paradoxus. John F. Eisenberg cited a specimen that lived in captivity for 11 years and four months, the longest recorded lifespan of this species (Nowak, 1999).
Range lifespan
Status: captivity: 11 (high) years.
Average lifespan
Status: captivity: 11.3 years.
Solenodon paradoxus can be found in wooded and brushy areas, often near areas of agriculturally developed land. Because solenodons are nocturnal they find shelter during the day in tunnel systems that they construct by burrowing through organic material and soil. They also take refuge in hollowed logs and trees, caves, and cracks in rocks.
Habitat Regions: tropical
Other Habitat Features: agricultural
Solenodon paradoxus can be found exclusively on the island of Hispaniola in Haiti and the Dominican Republic. Most specimens have been discovered in northern Hispaniola.
Biogeographic Regions: neotropical (Native )
Other Geographic Terms: island endemic
Reports conflict on whether Solenodon paradoxus consumes vegetation, along with their standard diet of invertebrates. Walker's Mammals of the World states that members of the genus Solenodon feeds on various fruits and vegetables. However, a study conducted by Erna Mohr found that solenodons refused all forms of vegetation. From this study, a list of items included in the diet of members of the genus Solenodon's was compiled from fecal analysis (Fons, 1990). This list is shown below. Solenodon paradoxus collects food by digging extensive tunnel systems under the ground, then foraging for insects and other invertebrates from the surrounding soil.
Foods eaten include: millipedes (Iulides), ground beetles (Carabidae), various orthopteran insects (Gryllidae, Tettigoniidae, Blattidae), earthworms (Lumbricidae) and various types of snails.
Animal Foods: insects; terrestrial non-insect arthropods; mollusks; terrestrial worms
Primary Diet: carnivore (Insectivore , Eats non-insect arthropods, Molluscivore , Vermivore)
Because of the small numbers of Solenodon paradoxus, it barely contributes, if at all, to its ecosystem. If Solenodon paradoxus were present in greater numbers it might effect the populations of insects and other invertebrates that it preys upon. Furthermore, its extensive burrowing and tunneling might contribute to soil aeration.
Because of its small numbers, Solenodon paradoxus is incapable of causing any significant detriment to the human economy. When it was present in higher numbers, farmers reported destruction of crops as a result of solenodon activity. However, this crop destruction was incidental to the solenodon's predation on insects beneath the soil.
Negative Impacts: crop pest
Perception Channels: tactile ; chemical
There is very little information available about Solenodon paradoxus. This may be a result of the geographic range of this species. Charles A. Woods, who has done research on this species, has found only 15 dead specimens and collected 3 reports of sightings from locals in Haiti (Woods, 1981).
Little is known about the mating system and behavior of Solenodon paradoxus. Before mating, the female constructs a nest in which she will birth and nurse her young. It is known that females have an estrus period that irregular and not coordinated with the seasons. Males, in contrast can mate at any time. When first introduced to each other, solendons may engage in aggressive behavior, but it is unknown whether this is an attempt at sexual dominance.
Mating System: polygynandrous (promiscuous)
Very little is known about the reproductive behavior of Solenodon paradoxus. This species breeds at an extremely slow rate, only twice per year. Newborns weigh from 40 to 55 grams and are 15.2 to 16.3 cm in length, with little hair and closed eyes (Fons, 1990). The information below was provided by Asdell's Patterns of Mammalian Reproduction (Hayssen, et al, 1993).
Breeding interval: These solenodons breed twice yearly.
Breeding season: Breeding seasonality is unknown.
Range number of offspring: 1 to 3.
Average gestation period: >50 days.
Average weaning age: 75 days.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Average birth mass: 100 g.
Average gestation period: 50 days.
Average number of offspring: 2.
The number of young that can survive is limited to the small number, two, of teats the female possesses. These are on her dorsal side, near the rump (International Wildlife Encyclopedia, 1974). Young are nursed for 13 weeks, at which time they begin to eat solid food. Solenodon paradoxus is born with only a minimal layer of hair, barely covering its body. A more dense coat fills in within 14 days. After 75 days, a young is no longer nursing and is eating solid food.
Parental Investment: altricial ; female parental care
The Last Survivors website raises awareness of the last surviving Caribbean endemic land mammals and focusses conservation attention on these valuable buthighly threatened species.
The Hispaniolan solenodon (Solenodon paradoxus), also known as the agouta,[3] 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.
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.[4]
The Hispaniolan solenodon resembles an oversized shrew; males and females are similar in size. Adults measure 49 to 72 cm (19 to 28 in) in total length, including a tail 20 to 25 cm (7.9 to 9.8 in) long, and weigh about 800 g (28 oz) 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.[5]
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 7 cm (2.8 in) in length, with a few smaller whiskers further back on the head.[5] 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.[6]
The dental formula for the species is 3.1.3.33.1.3.3 × 2 = 40. 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.[7] Although the exact chemical composition of the venom is unknown,[8] 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.[5]
Hispaniolan solenodons have patches of skin rich in apocrine glands on the thighs. The secretions of these glands are used in communication between individuals.[9]
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 1,000 m (3,300 ft) elevation, although they are sometimes found at higher altitudes or close to developed agricultural land.[2][5] There are two recognised subspecies:
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.[10] Its presence in Los Haitises National Park in the Dominican Republic is inferred, but unconfirmed.
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.[5]
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.[5]
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 40 to 55 g (1.4 to 1.9 oz). 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.[5]
The Hispaniolan solenodon is preyed upon by the ashy-faced owl (Tyto glaucops) and the Stygian owl (Asio stygius).[11] 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 mongooses (Urva auropunctata) were introduced to control rats in sugar cane fields; all three can potentially prey on solenodons.
In 2016, researchers at the University of Illinois and the University of Puerto Rico completely sequenced the mitochondrial genome of the Hispaniolan solenodon. The study confirmed that solenodons diverged from all other living mammals about 78 million years ago. The study also found that there is much greater genetic diversity among the northern population than the southern population.[12][13] This timeline aligns well with a hypothesis on how the Hispaniolan solenodon came to inhabit the island of Hispaniola. Geologists speculate that the island was part of a volcanic arc that connected to Mexico around 75 million years ago.[14]
Today, the solenodon is one of the last two surviving native insectivorous mammals found in the Caribbean, and one of the only two remaining endemic terrestrial mammal species of Hispaniola.[15]
While the survival of the solenodon is uncertain, talk of conservation has been underway through the "Last Survivors Project", which has been collaborating with the Dominican government. In 2009, a five-year plan for conservation was funded which has been put in place to conduct field research, discover the best means by which to bring about their conservation, and organize monitoring tools to ensure their long-term survival.[16][17]
One of the aims of the conservation efforts is to increase local awareness of the species, particularly in the Dominican Republic. The Ornithological Society of Hispaniola showed pictures of the solenodon to the locals in both countries, and few knew what they were due to their nocturnal nature.[18] The Hispaniolan solenodon was identified as one of the top ten "focal species" in 2007 by the EDGE Species project.[19] A collaborative conservation project funded by the Darwin Initiative (UK) was started in 2009 and is researching the species to conserve it.[20] The species is fully protected by law. However, national parks in both Haiti and the Dominican Republic are threatened by deforestation and encroachment for farming and charcoal production. The US Agency for International Development and the Nature Conservancy are working with local nongovernmental organisations to improve protection and implement management plans for these parks (the "Parks in Peril" programme). A recovery plan for the isolated Haitian population, published in 1992, advocated comprehensive surveys, improved management of the Pic Macaya National Park, education campaigns, control of exotic mammals, and an ex situ breeding programme. These recommendations have not yet been implemented.
Two conservation research and education programmes funded by the Darwin Initiative have recently been established, focusing on solenodons in both countries: "Building evidence and capacity to conserve Hispaniola's endemic land mammals" (started 2009), and "Building a future for Haiti's unique vertebrates" (started 2010). These collaborative projects represent a partnership between the EDGE Programme, the Durrell Wildlife Conservation Trust, BirdLife International, the Sociedad Ornitologica de la Hispaniola, the Dominican Republic National Zoo, Societe Audubon Haiti, and in-country project partners.
Habitat loss and predation by introduced species have contributed to it being considered an endangered species in the past. It was considered almost extinct until 1907, when it was found living in the interior of Hispaniola. It was not considered to be in immediate danger early in the 20th century. In 1966, it was found in several localities in the Dominican Republic. In 1981, after extensive searching, the Hispaniolan solenodon was declared "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. Wildlife filmmaker Jürgen Hoppe has been able to film the Hispaniolan solenodon in various parts of the Dominican Republic during the last 18 years. 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 it before releasing it back into the wild.[21]
Follow up work sequencing the whole genomes of six captured individuals more accurately predicts that solenodons diverged from other extant mammals 73.6 million years ago. Looking at single-nucleotide polymorphism (SNP) variation between northern and southern captured individuals enabled the researchers to infer population demography, which supported a likely subspecies split (S. paradoxus woodi the proposed name for the southern subspecies) within the Hispaniolan solenodon at least 300 thousand years ago.[22] The solenodon was downlisted from "Endangered" to "Least Concern" by the IUCN in 2020, on the basis of an increased awareness of its population size and range.
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.
