Star-Nosed Mole

## Description

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.

## Appearance

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.

## Distribution

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 drainage, 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 from water.

## Behavior

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 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.

## Diet

Star-nosed moles are carnivores (vermivores), they mainly eat invertebrates but they will also sometimes eat terrestrial insects, mollusks, aquatic crustaceans, and small fish.

## Reproduction

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 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, are about 49 mm in length and weigh about 1.5 g. Their eyes, ears and star are functional after around 2 weeks. They are independent when they are 30 days old and sexually mature at 10 months.

## Population

### Threats

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 future.

### Number

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.

### Ecological niche

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.

## Fun Facts

The nose of a Star-nosed mole is its most fascinating feature. With little use for eyesight, its tentacled nose is its sense organ to locate prey. The pink star on its nose consists of 22 fleshy tentacles, each with about 25,000 touch receptors, which are called Elmer’s organs.

The mole’s tentacles move extremely quickly and can touch up to 12 objects per second. They are thought to detect electrical fields as the animal moves forward.

Star-nosed moles smell when under water by breathing out air bubbles onto things and then breathing them in to smell scents they have trapped.

The nose of a Star-nosed mole is ideal for detecting earthquakes.

The Star-nosed mole’s fur helps to withstand water.

The Guinness Book of World Records lists this species among the fastest hunters.

This species hunts and seizes its victim so quickly that it is nearly impossible for humans to follow it.