Critter Catalog

What do they look like?

Brown Snakes are fairly small snakes, with a total body length of from 23 to 52.7 cm, though few Brown Snakes grow larger than 38 cm in length. They have stout bodies with large eyes and heavily keeled scales(with raised ridges along their length). Brown Snakes are brown, grayish brown,or tan in color, with two parallel rows of spots along the length of their backs. Between these two rows of spots the background color is typically lighter than on the rest of the body. This coloration makes them very difficult to see. Their belly is cream to pinkish in color, with small dark spots along the edges. They have small, dark heads with a darkish band at the jawline. Typically there are 17 scale rows at midbody and the anal plate is divided. Males and females generally look the same, but males tend to have longer tails and females are slightly larger. Young Brown Snakes are small, from 7 to 11.7 cm in length. A distinguishing characteristic of the young is a light grayish-white colored ring found around the neck. At this age they are sometimes confused with Ring-necked Snakes. They are distinguished from Ring-necked Snakes by their keeled scales, Ring-necked Snakes have smooth scales.

• Other Physical Features
• heterothermic

• Sexual Dimorphism
• female larger
• sexes shaped differently

• Range length

  23.0 to 52.7 cm

  9.06 to 20.75 in

Where do they live?

Brown Snakes are widely distributed. They are found in southern Canada, in the United States east of the Rocky Mountains, and in the northern portions of Mexico.

• Biogeographic Regions
• nearctic
  • native

What kind of habitat do they need?

Brown snakes are found in a variety of habitats, from dense woods to open prairies and marshes. They prefer moist soils but are also found in dry areas. These wide habitat tolerances mean that brown snakes are also found in urban, suburban, and agricultural areas. Brown snakes are typically found hiding among loose stones, flat rocks, or other forms of cover. These snakes will spend most of their life under the ground, but during heavy rains they will sometimes emerge into the open. They are sometimes seen in October to November and during late March or April, when they are moving to or from hibernation spots. Hibernation spots may be shared with other snakes, such as garter snakes, red-bellied Snakes, and smooth green snakes.

• These animals are found in the following types of habitat
• temperate
• terrestrial

• Terrestrial Biomes
• chaparral
• forest
• scrub forest

• Wetlands
• marsh

• Other Habitat Features
• urban
• suburban

How do they reproduce?

• Mating System
• polygynous

Brown Snakes give birth to from 3 to 41, but more often 10 to 14, live young in late summer, from July to August. Brown snakes reach sexual maturity by the end of their second summer, usually by this time they have doubled in length.

• Key Reproductive Features
• iteroparous
• seasonal breeding
• sexual
• fertilization
  • internal
• ovoviviparous

• How often does reproduction occur?

  Brown Snakes breed once yearly.

• Breeding season

  Brown Snakes give birth to their young in late summer.

• Range number of offspring

  3.0 to 41.0

• Average age at sexual or reproductive maturity (female)

  2.0 years

• Average age at sexual or reproductive maturity (female)
  Sex: female

  730 days

  AnAge

• Average age at sexual or reproductive maturity (male)

  2.0 years

• Average age at sexual or reproductive maturity (male)
  Sex: male

  730 days

  AnAge

The young are nourished within their mother's body while they develop. Once the young are born there is no further parental care, but sometimes young Brown Snakes will stay near their mother.

• Parental Investment
• precocial
• female parental care

How long do they live?

Little is known of Brown Snake lifespans in the wild, but a captive individual lived to be 7 years old. Wild Brown Snakes may approach this lifespan in the wild, though many young die before becoming mature.

• Range lifespan
  Status: captivity

  7.0 (high) years

• Average lifespan
  Status: captivity

  7 years

  AnAge

How do they behave?

Brown Snakes are harmless, nonvenemous snakes. They are shy and secretive and spend most of their lives underground or under cover. They hibernate in the burrows of other animals, such as those of rodents, in abandoned anthills, under logs, in rock crevices, or buildings. They share hibernation sites with other species of snakes and typically return year after year to the same hibernation spot. Brown Snakes are most active at night, particularly during the summer, and are mainly solitary animals, except when they congregate at hibernation sites.

• Key Behaviors
• nocturnal
• motile
• solitary

How do they communicate with each other?

Brown Snakes communicate with each other primarily through touch and smell. They use their forked tongues to collect chemicals from the air and insert these forks into a special organ in the roof of their mouth, which interprets these chemical signals. Because Brown Snakes hunt mostly underground and at night, they probably use almost exclusively their sense of smell to find prey. Snakes are also sensitive to vibrations and have reasonably good vision.

What do they eat?

Brown snakes feed largely on earthworms, snails, and slugs, but will also eat small salamanders, soft-bodied grubs, and beetles. They have specialized teeth and jaws that allow them to pull snails out of their shells and eat them.

• Primary Diet
• carnivore
  • molluscivore
  • vermivore

• Animal Foods
• amphibians
• insects
• terrestrial non-insect arthropods
• mollusks
• terrestrial worms

What eats them and how do they avoid being eaten?

Brown snakes are eaten by large frogs and toads, larger snakes, American crows, hawks, shrews, weasels, blue jays, and domestic cats. When these snakes feel threatened they flatten their bodies to appear larger and place their bodies in an aggressive posture. They will also smear their attacker with a foul-smelling musk that they exude from their cloaca.

• Known Predators

  • large frogs and toads (Anura)
  • snakes (Serpentes)
  • American crows (Corvus brachyrhynchos)
  • hawks (Accipitridae)
  • shrews (Soricidae)
  • weasels (Mustela)
  • domestic cats (Felis silvestris)
  • blue jays (Cyanocitta cristata)

What roles do they have in the ecosystem?

Brown Snakes help to control populations of snails, slugs, and earthworms. They also serve as a valuable food supply for their predators.

How do they interact with us?

These little snakes benefit humans by controlling slug and snail damage in gardens.

• Ways that people benefit from these animals:
• controls pest population

Are they endangered?

Brown Snakes are widespread and relatively common but they are adversely affected by development and contamination of the areas that they occupy.

• IUCN Red List

  Least Concern
  More information

• IUCN Red List

  Least Concern
  More information

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  No special status

Contributors

Leslie Seaholm (author), Michigan State University, James Harding (editor), Michigan State University.

References

Collins, J. 1987. Snakes Ecology and Evolutionary Biology. New York: Macmillan Publishing Company.

Ditmars, R. 1936. The Reptiles of North America. New York: Doubleday, Doran and Company, Inc..

Harding, J. 1997. Amphibians and Reptiles of the Great Lakes Region. Ann Arbor: The University of Michigan Press.

Simon, H. 1979. Easy Classification Guide to North American Snakes. New York: Dodd, Mead, and Company.