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 mole feels its way around. With the help of its Eimer's organs, it may be perfectly poised to detect seismic wave vibrations.
The Star-nosed mole is a very distinctive mammal, with black fur, and wide forefeet tipped with talons that are designed for digging. The palms of their pinkish and black feet face outwards. Their tail is long and hairy. The snout for which they are named has on its tip 11 pairs of little pink tentacles, splayed out like a star. The nose is about 1 cm (0.4 in) in diameter with its Eimer's organs distributed on 22 appendages. 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.
The Star-nosed mole is a native of eastern North America (northeastern United States and southeastern Canada). Its range goes from the Atlantic Ocean westwards to North Dakota and Manitoba and south to Virginia and Ohio. It also occurs on the Atlantic coast southwards to Georgia and throughout the Appalachian Mountains. This species is found in a range of habitats that have moist soil. These animals prefer areas with poor drainages, such as coniferous and deciduous forests, wet meadows, clearings, marshes, and peatlands. They will also inhabit stream banks, lakes, and ponds, and will venture into them for food. Although preferring wet areas, these moles have been seen in dry meadows up to 400 m (0.25 miles) from water.
Star-nosed moles are diurnal animals and are active throughout the year. They prefer wet areas and they tunnel through swampy areas, digging systems of shallow tunnels underground, as well as deeper ones. Nests are built on a raised area that is drier. This species is semi-aquatic and sometimes their tunnels open directly into the water. They can swim well and will dive for several seconds, sometimes remaining underwater for over 30 seconds. During winter Star-nosed moles hunt more in water because the wet ground is likely to be frozen, and they will even swim under ice. If they come above ground searching for food it is usually at night. Little is known about how they communicate with each other. Young Star-nosed moles produce high-pitched noises and adults make wheezing sounds.
Star-nosed moles are carnivores (vermivores), they mainly eat invertebrates but they will also sometimes eat terrestrial insects, mollusks, aquatic crustaceans, and small fish.
The Star-nosed mole appears to be serially monogamous, with pairs remaining together for one breeding season. Males and females seem to pair up in autumn and stay together for the duration of the mating season, which is March and April. Gestation is for about 45 days, with the young being born in late April until mid-June. A female produces one litter per year of 2 to 7 young, with 5 being a typical litter size. The young are hairless at birth. Their eyes, ears, and star are functional after around 2 weeks. They are independent when they are 30 days old and become reproductively mature at 10 months of age.
There are no major threats to the Star-nosed mole. However, since it depends on wetlands for its survival, ongoing destruction of these areas to house an expanding human population could affect this species in the future.
According to IUCN, Star-nosed mole is common and widespread throughout its range but no overall population estimate is available. Currently, this species is classified as Least Concern (LC) and its numbers today remain stable.
The Star-nosed mole has an important role in many wetland ecosystems, providing food for some carnivores and consuming many aquatic invertebrates. In its tunneling through the moist ground, it provides aeration for the roots of plants that otherwise might be trapped in soil that is anoxic.