Star-nosed Mole

The star-nosed mole is a small, semi-aquatic mole found in wet lowland areas of eastern North America, easily recognized by the unique fleshy tentacles surrounding its nose. It is remarkable for possessing one of the most sensitive touch organs in the animal kingdom, allowing it to identify and consume prey faster than any other mammal. This species spends much of its life underground or in water, rarely seen by humans.

Eastern Canada and northeastern United States, including wetlands of the Great Lakes region and Atlantic coast

Found from southeastern Canada (Quebec, Ontario, Manitoba) south through the northeastern and mid-Atlantic United States to Georgia, concentrated in the Great Lakes region and Appalachian wetlands.

Altitude and depth

Sea level to about 1000m elevation; burrows typically extend just below the surface down to around 20-30cm deep, with some tunnels reaching below the water table.

Seasonal movements

No hibernation; remains active year-round even under snow and ice, though breeding is seasonal in early spring.

Wet lowland habitats including marshes, swamps, wet meadows, and the banks of streams and ponds; prefers poorly drained soils near water bodies.

Adaptations to its environment

The star-shaped nasal appendage with 22 fleshy tentacles contains over 25,000 Eimer's organs for tactile sensing, enabling ultra-fast prey detection in dark, muddy environments. Dense waterproof fur and small eyes reflect adaptation to a fossorial and semi-aquatic lifestyle, and it can smell underwater by blowing and re-inhaling air bubbles.

Listed as Least Concern by the IUCN due to a wide range and presumed large, stable population without major range-wide declines.

Estimated population

Population size is not precisely quantified but is considered abundant and stable across its range, given the still large extent of suitable wetland habitat.

Wetland drainage and development, agricultural conversion of habitat, and water pollution affecting prey availability are the primary localized threats.

Diseases and parasites

Known to host various ectoparasites such as mites and fleas, as well as internal parasites like nematodes, though no major disease threats have been documented.

No species-specific conservation programs exist, but the mole benefits indirectly from wetland protection laws and habitat conservation efforts in the U.S. and Canada.

Recommended actions

Continued protection and restoration of wetland ecosystems, monitoring of local population trends, and prevention of water pollution in its habitat.

Blackish-brown dense, water-repellent fur covers a cylindrical body with a naked, scaly tail; the most distinctive feature is the pink, star-shaped ring of 22 fleshy tentacles at the tip of the snout.

Size

Body length of 15-20 cm including a 7-8.5 cm tail.

Weight

Approximately 35-75 grams.

Distinctive features

Unlike other North American moles, it has the unique tentacled nasal star, a longer scaly tail, and partially webbed feet adapted for swimming.

Differences between males and females

Minimal; males and females are similar in size and appearance, though males may be slightly larger during breeding season.

Generally solitary outside of breeding season, though individuals may share burrow systems in loose colonies in favorable habitat.

When it is active

Active both day and night in a polyphasic pattern of short activity bursts separated by rest periods, with no strong diurnal or nocturnal preference due to its subterranean lifestyle.

Diet

Carnivorous, feeding on earthworms, insect larvae, small aquatic invertebrates, and occasionally small fish or amphibians.

How it feeds and hunts

Uses rapid tactile scanning with its star-shaped nose to detect and identify prey in milliseconds, then swiftly captures it with specialized incisors; can locate and eat prey in as little as 120 milliseconds.

Communication

Primarily relies on tactile and olfactory cues rather than vocalizations; scent marking may play a role in territory and mate recognition.

Interactions with other species

Preyed upon by owls, hawks, skunks, weasels, and domestic cats; competes with other small mammals for invertebrate prey in wetland soils.

Role in its ecosystem

Plays a role in soil aeration and invertebrate population control within wetland ecosystems, and serves as prey for various predators, contributing to local food web dynamics.

Breeding occurs in late winter to early spring (March-April); gestation lasts about 45 days, producing a litter of 2-7 young.

Raising the young

Females raise the altricial young alone in nest chambers lined with vegetation; pups are weaned at around 3-4 weeks and become independent shortly thereafter.

Maturity and lifespan

Sexual maturity is reached around 10 months of age; lifespan in the wild is typically 3-4 years, with limited data on captivity due to difficulty maintaining the species.

Classification

Mammalia > Eulipotyphla > Talpidae > Condylura > Condylura cristata

Scientific synonyms

Sorex cristatus (original 1758 Linnaeus classification)

Recent studies

Recent neuroscience research by Kenneth Catania has revealed that the star organ processes touch information faster than any known mammalian sensory system, providing insights into rapid neural processing.

Genome and DNA

Diploid chromosome number is 2n=34; the species has been studied for its unique sensory system genetics related to Eimer's organ development.

Compared with similar species

Compared to the Eastern mole (Scalopus aquaticus), the star-nosed mole is more aquatic, has a longer tail, and lacks the smooth snout, instead bearing its signature tentacled star.

It can smell underwater by exhaling and re-inhaling air bubbles, and it holds the record for the fastest-eating mammal, identifying and consuming prey in under a quarter of a second.

Where and how to see it

Best observed near wetlands and stream banks in the northeastern U.S. or eastern Canada during early morning hours in spring, though sightings are rare due to its subterranean and aquatic habits; camera traps near burrow entrances increase chances of observation.

Risks to humans

No notable risk to humans; it is not aggressive and rarely encountered.

Human uses

No significant direct human use; primarily of scientific interest for research into sensory biology and neural processing.