• The blackneck garter snake (Thamnophis cyrtopsis), named for the black blotches behind its jaws, has a large population that ranges from southern Colorado and Utah south into Mexico and Guatemala.

    Nonvenomous, it grows to be 40.5–71 centimeters (16 to 28 inches) long. It likes to eat amphibians, especially frogs, toads, and tadpoles, as well as fish. Sometimes it also eats skinks, crustaceans, and earthworms.

    If threatened or disturbed, this garter snake emits a strong, unpleasant smelling musk from its anal glands and may also expel feces. To make itself look larger, it might also flatten its head and body when it feels it’s in danger. These snakes generally do not bite, though, unless seriously provoked.

    Blackneck garter snakes communicate with each other mainly through the release of chemical pheromones. They also have an inner ear through which they can detect sounds, and they can sense vibrations in the ground through their jawbone.

    The blackneck garter snake occurs in a wide range of habitats, from dry deserts to forested mountains. It prefers being near a consistent water source, which could be anything from a stream to a lawn sprinkler.

    Introduced species, such as bullfrogs and sunfish, feed on the blackneck garter snake and also compete with them for prey, which impacts the garter snake’s population. In some areas, its habitat has been lost or fragmented because of urbanization, deforestation, or the expansion of agriculture. Even so, the International Union for Conservation of Nature (IUCN) has listed their status as being of least concern and their population is considered relatively stable.

    1. What are the characteristics of the blackneck garter snake’s early life?

      The blacknecked garter snake is born live, after it grows in an egg within its mother’s body. With this type of birth, garter snakes are considered oviparous. Blackneck garter snakes are 8–10 inches (20–25 cm), with between 1 and 24 offspring at a time. The young go off on their own right away, having no more association with their mother.

    2. How are blackneck garter snakes part of a food web?

      Blacknecked garter snakes eat a variety of prey: frogs, toads, tadpoles, fish, skinks, crustaceans, and earthworms. They are also prey for a variety of other vertebrates, including bullfrogs, sunfish, and other snake species. Flatworm and roundworm species can also live in these snakes, some being parasitic, or causing harm, and others commensal, providing benefits to the snake.

    3. Why can it be hard to find snakes such as the blacknecked garter snakes in the wild?

      These snakes’ skin pattern helps to camouflage them in their natural habitat. They can also sense that a human is walking nearby, as they detect sounds and sense vibrations in the ground and move quickly to hide.

  • Term Part of Speech Definition Encyclopedic Entry
    agriculture Noun

    the art and science of cultivating the land for growing crops (farming) or raising livestock (ranching).

    Encyclopedic Entry: agriculture
    amphibian Noun

    an animal able to live both on land and in water.

    anal gland Noun

    one of two sacs located on either side of the anus of some mammals, which secrete a liquid used to identify members of a species. Also called anal sacs or scent glands.

    crustacean Noun

    type of animal (an arthropod) with a hard shell and segmented body that usually lives in the water.

    deforestation Noun

    destruction or removal of forests and their undergrowth.

    feces Plural Noun

    waste material produced by the living body of an organism.

    habitat Noun

    environment where an organism lives throughout the year or for shorter periods of time.

    Encyclopedic Entry: habitat
    International Union for the Conservation of Nature (IUCN) Noun

    environmental organization concerned with preserving natural ecosystems and habitats.

    pheromone Noun

    substance released by an animal that influences the behavior of other animals of the same species.

    population Noun

    total number of people or organisms in a particular area.

    provoke Verb

    to annoy or make angry.

    urbanization Noun

    process in which there is an increase in the number of people living and working in a city or metropolitan area.

    venomous Adjective

    having to do with venom or organisms that secrete venom.