Found in the more ‘moist’ parts of North America, the star-nosed moles are not uncommon, just uncommonly seen.
The distinctive star-shaped organ on the end of their nose is touch-sensitive and made up of over 25,000 minute sensory receptors that they use to feel their way around.
No bigger than an average hamster, these moles also use their noses to blow bubbles under water to sniff out their prey, making them the only known mammal that can smell underwater.
The star-nosed mole (Condylura cristata) is a small mole found in moist, low areas in the northern parts of North America. It is the only member of the tribe having a touch organ with more than 25,000 minute sensory receptors, known as Eimer’s organs, with which this hamster-sized mole feels its way around. With the help of its Eimer’s organs, it may be perfectly poised to detect seismic wave vibrations.
The extremely sensitive star-like structure is covered with minute touch receptors known as Eimer’s organs. The nose is about 1 cm in diameter with roughly 25,000 Eimer’s organs distributed on 22 appendages. Eimer’s organs were first described in the European mole in 1871 by German zoologist Theodor Eimer. Other mole species also possess Eimer’s organs, though they are not as specialized or numerous as in the star-nosed mole.
Because the star-nosed mole is functionally blind, the snout was long suspected to be used to detect electrical activity in prey animals,though little, if any, empirical support has been found for this hypothesis. The nasal star and dentition of this species appear to be primarily adapted to exploit extremely small prey. A report in the journal Nature gives this animal the title of fastest-eating mammal, taking as little as 120 milliseconds (average: 227 ms) to identify and consume individual food items.Its brain decides in approximately 8 ms if prey is edible or not. This speed is at the limit of the speed of neurons.
These moles are also able to smell underwater, accomplished by exhaling air bubbles onto objects or scent trails and then inhaling the bubbles to carry scents back through the nose.
The star-nosed mole lives in wet lowland areas and eats small invertebrates such as aquatic insects (such as the larvae of caddisflies, midges, dragonflies, damselflies, crane flies, horseflies, predaceous diving beetles, and stoneflies), terrestrial insects,worms (such as earthworms, leeches, and other annelids), mollusks, and aquatic crustaceans, as well as small amphibians and small fish. Condylura cristata has also been found in dry meadows farther away from water.
They have also been found in the Great Smoky Mountains as high as 1,676 meters. However, the star-nose mole does prefer wet, poorly drained areas and marshes. It is a good swimmer and can forage along the bottoms of streams and ponds. Like other moles, this animal digs shallow surface tunnels for foraging; often, these tunnels exit underwater.
It is active day and night and remains active in winter when it has been observed tunneling through the snow and swimming in ice-covered streams. C. cristata is particularly adept at thermoregulation, maintaining a high body temperature in a wide range of external conditions relative to other Talpid moles. This explains its ability to thrive in cold aquatic environments. Little is known about the social behavior of the species, but it is suspected to be colonial.
This mole mates in late winter or early spring, and the female has one litter of typically four or five young in late spring or early summer. However, females are known to have a second litter if their first is unsuccessful. At birth, each offspring is about 5 cm (2 in) long, hairless, and weighs about 1.5 g.
Their eyes, ears, and star are all sealed, only opening and becoming useful about 14 days after birth. They become independent after about 30 days and are fully mature after 10 months. Predators include the red-tailed hawk, great horned owl, barn owl, screech owl, foxes, weasels, minks, various skunks and mustelids, and large fish such as the northern pike, as well as domestic cats.