Oryzorictes hova
Hova rice tenrec
(Also: molelike rice tenrec)

Mole tenrecs, Oryzorictes hova, are endemic to the island of Madagascar, the result of a spectacular radiation from the single colonizing ancestor of all Malagasy tenrecs. (Goodman, 2003)

Mole tenrecs inhabit the forested regions of Madagascar, from lowland humid forests to high elevation localities near tree line. Although semifossorial in nature, O. hova is also broadly distributed throughout wet bottomlands including agricultural sites (converted rice paddies) and natural marshes. (Goodman and Rakotondravony, 2000; Goodman et al., 1997; Goodman, 2003)

Members of the genus Oryzorictes measure between 99 and 124 mm in length, and are between 28 g and 40 g. They share several of the morphological characters that typify semifossorial insectivores. Well developed forelimbs and elongated claws are accompanied by small eyes and ears. Albinism is expressed in some populations of O. hova, although more frequently a brown-tan bicoloration of the dorsal and ventral pelage is seen.

The principle morphological character that has defined both species of Oryzorictes is the relative number of toes on the forearm. As the name implies, Oryzorictes tetradactylus has only four toes. Other members of the genus have five toes. The relative length of the tail has also been used to distinguish O. hova and O. tetradactylus, the latter possessing a distinctly shorter tail. However significant overlap in observed tail lengths has been noted. (Goodman, 2003)

Specimens of Oryzorictes have been successfully kept in captivity, but full lifespan data have never been published. Lifespan data for wild specimens have never been collected. Long-tailed tenrecs, in the genus Microgale have been reported to live between 5 and 6 years. Because they are similar in size to Oryzorictes, lifespans may be similar. (Goodman, 2003; Gould and Eisenberg, 1966; Nowak, 1999)

Oryzorictes hova is a semifossorial species with locomotary adaptations similar to those of the true moles in the family Talpidae. Populations have never been noted in significant densities other than in anecdotal accounts by local farmers in rice paddies.

Daily torpor has been noted in many of the tenrecs, but has never been directly observed in Oryzorictes.

On the whole, little is known about semifossorial tenrecs. Trapping success of this species and the other semifossorial Oryzorictinae (Microgale gracilis, Microgale gymnohyncha) is very low, and often correlates with rains that flood their natural burrows. Trends in relative seasonal populations and estimated densities are unknown as a result, as O. hova handily avoids most current trapping techniques. (Eisenberg and Muckenhirn, 1968; Goodman and Rakotondravony, 2000; Goodman, 2003)

Nowak (1999) reports that members of the genus Oryzorictes are thought to be mainly nocturnal. Oryzorichtes hova is thought to sometimes forage above ground, using its muzzel to probe beneath ground cover. However, because these animals are active underground also, it is difficult to know for certain whether they move about at other times of day. (Nowak, 1999)

Home Range

Because of low trapping success of this species, the size of home ranges is not known. (Goodman, 2003)

Oryzorictes has relatively underdeveloped eyes and ears, presumably relying on its tactile senses to navigate underground. Both species possesses a long, ennervated rostrum for touch perception, and probably rely on their sense of smell to direct them to areas of high prey density. However, little is known about aspects of social communication or environmental perception beyond these morphological observations. (Goodman, 2003)

Nothing is known of the feeding habits of Oryzorictes other than data obtained through stomach content analyses. A high proportion of insects, earthworms, and some vegetable matter have been reported, but no further research has been conducted. (Goodman, 2003)

The semifossorial nature of this species protects it from many of the natural predators of Madagascar. However, remains have been observed in owl pellets and the intestinal tract of at least one fossorial snake. (Goodman, 2003)

The role of Oryzorictes in ecosystem function is poorly understood, as data on their natural history are almost nonexistent. Despite this, this genus of tenrecs represents a unique example of adaptation to fill an available niche. The lack an extensive predator base as found on other continents suggests Madagascar's semifossorial species do not play as critical a role as the moles and gophers of North America's varied ecosystems in sustaining predator populations. Beyond this, we can speculate that O. hova plays some role in controlling insect and earthworm populations, and may help to aerate the soil. Further speculation is not possible with the scant information known about the island's complex ecosystems. (Goodman, 2003)

Oryzorictes hova has been known to inhabit rice paddies in considerable densities, causing damage to young plants by uprooting shoots while burrowing. (Goodman, 2003)

Other than its inherent value as a representative species of Madagascar's endemic biota, this species has little economic importance.

The conservation status of these animals has not been evaluated.

An extensive review of the taxonomic history of Oryzorictes synonymized a previously recognized species, Oryzorictes hova with Oryzorictes hova after an extensive review of cranial and dental synapomorphies. (Goodman, 2003)