Andaman White-toothed Shrew

The Andaman White-toothed Shrew is a small insectivorous mammal endemic to South Andaman Island in the Bay of Bengal. It is one of the rarest and least-known shrews in the world, known from only a handful of specimens collected decades ago. Its extreme restriction to a tiny island range and lack of recent confirmed sightings make it a species of high conservation concern. It exemplifies the vulnerability of island endemics to habitat loss and invasive species.

Endemic to South Andaman Island, India

Known only from South Andaman Island, part of the Andaman and Nicobar Islands, India, in the Bay of Bengal. No confirmed records from other islands in the archipelago.

Altitude and depth

Lowland forest, generally below 300m elevation

Tropical moist evergreen and semi-evergreen forest, including leaf litter and undergrowth near forest floor. May also use secondary forest and forest edges close to human settlements.

Adaptations to its environment

Small body size and high metabolic rate typical of shrews allow efficient exploitation of invertebrate prey in leaf litter. Nocturnal/crepuscular habits and dense fur help minimize water loss in humid tropical forest conditions.

Critically Endangered (IUCN) due to extremely restricted range, small and possibly declining population, and severe habitat degradation on South Andaman Island. Very few specimens have been recorded, and there is uncertainty whether extant populations still persist.

Estimated population

Unknown; population size has not been reliably estimated, but presumed to be very small given the extremely restricted range and rarity of records; trend presumed declining.

Habitat destruction from logging, agricultural expansion, and human settlement; predation and competition from invasive species such as rats and cats; small population size increasing vulnerability to stochastic events.

Some protection may be afforded incidentally through forest reserves and protected areas on South Andaman Island, but no species-specific conservation programs are known to exist for this shrew.

Recommended actions

Conduct targeted surveys to confirm continued existence and assess population status; protect remaining forest habitat on South Andaman Island; control invasive predators; include species in regional biodiversity monitoring programs.

Small shrew with soft grayish-brown to dark brown dorsal fur and paler underparts, a pointed snout, small eyes, and a moderately long tail. White-tipped teeth are characteristic of the Crocidura genus, giving the common name 'white-toothed shrew'.

Size

Head-body length approximately 60-75 mm, tail approximately 35-45 mm

Weight

Estimated 4-7 grams, typical for small Crocidura shrews

Distinctive features

Distinguished from other Andaman shrews primarily through subtle differences in skull morphology, dentition, and body proportions rather than obvious external features; taxonomic identification often requires specimen examination.

Presumed solitary, as is typical for most Crocidura shrews, with limited social interaction outside of breeding encounters.

When it is active

Likely nocturnal to crepuscular, consistent with general shrew behavior patterns, though direct behavioral observations are lacking.

Diet

Insectivorous, likely feeding on small invertebrates such as insects, larvae, worms, and other arthropods found in leaf litter and soil.

How it feeds and hunts

Presumed active foraging through leaf litter and soil surface using acute smell and touch (whiskers) to detect small invertebrate prey, typical of Crocidura species.

Communication

Likely uses high-frequency vocalizations, chemical/scent marking, and tactile cues typical of shrews, though specific studies on this species are lacking.

Interactions with other species

Likely predated upon by owls, snakes, and introduced predators such as feral cats; may compete with other small mammals for invertebrate prey resources.

Role in its ecosystem

Plays a role as an insectivorous predator in the forest leaf-litter ecosystem, helping regulate invertebrate populations and potentially serving as prey for various forest predators.

Reproductive biology is essentially undocumented for this species; based on related Crocidura species, likely has short gestation (around 4 weeks) and multiple small litters per year.

Raising the young

Unknown for this species specifically, but likely follows typical shrew pattern of sole maternal care, with young weaned within a few weeks of birth.

Maturity and lifespan

Unknown specifically for this species; related Crocidura shrews typically reach sexual maturity within a few months and have short lifespans of 1-3 years in the wild.

Classification

Mammalia > Eulipotyphla > Soricidae > Crocidura > Crocidura andamanensis

Scientific synonyms

Crocidura hispida (sometimes treated as synonym or closely related taxon; taxonomic status debated)

Recent studies

Recent taxonomic reviews have focused on clarifying the distinctiveness of C. andamanensis relative to other Andaman shrews (e.g., C. hispida, C. jenkinsi), with molecular and morphological studies needed to resolve species boundaries.

Compared with similar species

Closely related to other Andaman endemic shrews such as Crocidura hispida and Crocidura jenkinsi, with which it may share overlapping morphological traits, making field identification challenging without specimen analysis.

This shrew is known from only a few museum specimens, making it one of the least-documented mammals in the world. It belongs to a small radiation of endemic shrews found only on the isolated Andaman Islands, highlighting unique island evolution.

Where and how to see it

Extremely difficult to observe due to rarity and lack of confirmed recent sightings; any observation attempts would require access to remaining forest patches on South Andaman Island with permission from Indian forestry and wildlife authorities.

Risks to humans

No notable risk to humans