Northern water snakes live in or near every type of freshwater habitat in southeastern Canada and the mideastern and northeastern United States. They are found in rivers, lakes, bogs, ponds, and wetlands. They are one of 27 varieties (species and sub-species) of snake native to Maryland.
You can see this species on exhibit in the Maryland Wilderness Tree at The Maryland Zoo in Baltimore.
Northern water snakes are often seen swimming near the shoreline or in open water, or basking on the bank or in a tree, shrub, or log protruding over water. These snakes stay near the water’s edge and quickly return to the water if disturbed. They are relatively large and thick-bodied, variable in color, and generally ranging between 3 and 5 feet long.
Northern water snakes are solitary animals when active during the warmer months, but congregate in communal brumation dens with other snakes during the winter. Brumation is very similar to hibernation but involves different metabolic processes and allows the animal to be mostly asleep but still capable of occasional activity, such as waking up to drink water
Northern water snakes are opportunistic feeders that hunt and scavenge for food. They eat primarily fish, frogs, tadpoles, and salamanders but will take other prey if available. They sometimes herd schools of small fish or tadpoles to the shoreline so that they can prey upon many at once.
Many people mistake non-venomous water snakes for water moccasins, also known as “cottonmouths.” The northern water snake is common in the Mid-Atlantic and New England regions of the U.S. while the water moccasin is found only in the southeastern U.S.
Northern water snakes typically mate in May and June and females give birth to somewhere between 20 and 40 live young in August and September. The young are independent at birth and receive no parental care.
Northern water snakes are preyed upon most often by raccoons, opossum, skunk, foxes, snapping turtles, and certain other snakes. Juveniles are most vulnerable. When threatened, a northern water snake will try first to escape to water. If cornered or picked up, it will strike aggressively and release a foul-smelling musk.
Northern water snakes are common throughout their range, including Maryland. However, in Maryland they and all native snakes are protected by the Nongame and Endangered Species Conservation Act. This means that native Maryland snakes cannot be killed, possessed, bred, or sold without first acquiring the proper permit from the Department of Natural Resources. Additionally, according to the Maryland DNR website, Maryland requires a Captive Reptile and Amphibian Permit for the possession, breeding, and sale of native reptiles and amphibians in the state.