Star-nosed mole

The star-nosed mole (Condylura cristata) is a small, semiaquatic mammal that lives in damp, low-lying areas of northeastern North America. It is the only living species in its tribe and genus. Its most striking feature is a star-shaped snout, about 1.5 cm across, made up of 22 fleshy appendages covered in more than 25,000 tiny touch receptors called Eimer’s organs.

These organs, first described in the European mole in 1872 by Theodor Eimer, are found in other moles but are far more numerous and specialized here. Because the mole is functionally blind, its nose was long thought to detect electrical signals from prey, but this idea lacks solid evidence. Instead, the star and teeth are adapted for handling very small prey.

Behavior

This animal holds the title of fastest-eating mammal, taking as little as 120 milliseconds (average 227 ms) to find and eat a food item. Its brain decides if something is edible in about eight milliseconds, pushing the limits of neural speed. It can also smell underwater by blowing air bubbles onto objects or scent trails and then inhaling them.

Ecology and behavior

The star-nosed mole lives in wet lowlands and eats small invertebrates like aquatic insect larvae (caddisflies, midges, dragonflies, and others), worms, mollusks, crustaceans, small amphibians, and small fish. It is also found in dry meadows and as high as 1,676 m in the Great Smoky Mountains, but it prefers wet, poorly drained areas and marshes. A strong swimmer, it forages along stream and pond bottoms. Like other moles, it digs shallow surface tunnels, often exiting underwater.

It is active day and night, even in winter, when it tunnels through snow and swims under ice. It is especially good at regulating body temperature, which helps it thrive in cold water. Little is known about its social life, but it may be colonial.

Mating occurs in late winter or early spring, and females have one litter of four or five young in late spring or early summer, with a possible second litter if the first fails. Newborns are about 5 cm long, hairless, and weigh 1.5 g, with sealed eyes, ears, and star that open around 14 days. They become independent after about 30 days and mature at 10 months. Predators include red-tailed hawks, great horned owls, barn owls, screech owls, foxes, weasels, minks, skunks, mustelids, large fish like northern pike, and domestic cats.