That Reptile Blog – Reptile, Amphibian and Exotic Pet Care and Information

Please see Parts I and II of this article for additional information on garter snake husbandry and natural history.  Today I’ll cover some often over-looked aspects of garter snake care that may help to explain why these relatively hardy snakes, and the related ribbon and water snakes, often fail to live as long as might be expected in captivity.

Thermal Gradient

A thermal gradient (varying temperatures within the terrarium) is beneficial to nearly all reptiles, but seems particularly important in maintaining the health of captive garter snakes.  This is especially true for Butler’s Garter Snakes (T. butleri), Common Garter Snakes (T. sirtalis) and others that range into the northern half of the USA.

Depending upon the species in question, garter, ribbon and water snakes do best at an ambient temperature of 72-82 F, with a warmer basking site (90-95 F) and a drop to 68 F or so at night.  Northern species should ideally be subjected to a winter cooling-off period, even if breeding is not contemplated.

UVA Light

There is some evidence that garter and related snakes (as well as Rough and Smooth Green Snakes, Opheodrys aestivus and O. vernalis), may benefit from exposure to UVA light.

A ZooMed Repti Halogen Bulb should be provided during their normal daytime cycle.  Even if not strictly necessary for survival, UVA encourages natural behavior, reproduction and, possibly, a strong immune system.

UVB Light

While snakes have not been shown to require UVB light exposure, anecdotal reports from successful garter and water snake keepers lead me to believe that these snakes may differ from most in this regard.

The Zoo Med 2.0 fluorescent lamp is specifically designed for animals needing moderate amounts of UVB light, and may be a prudent addition to the garter snake terrarium.  This bulb also supports vigorous plant growth…in contrast to most snake species, garter and ribbon snakes are very well-suited for terrariums housing sturdy live plants.

Further Reading

Laboratory guidelines concerning the importance of thermal gradients and related aspects of reptile care are posted here.

Next time we’ll cover nutrition and the care of individual garter snake species.

Please see Part I of this article for background information on these snake-keepers’ favorites.  Garter Snakes and the closely related ribbon and water snakes usually make hardy captives, yet there are very few records of individuals surviving over 10 years.  I believe this may have to do with some of their unique environmental and dietary needs (I’ll cover temperature, light and diet in Part III of this article).

Natural vs. Captive Habitats

Nearly all garter and ribbon snakes favor swamps, wet meadows, pond edges and other moist habitats.  Oddly, however, they are very susceptible to skin infections (“blister disease”) when kept on damp substrates – even more so than snakes native to dry environments.  This holds true even for those that spend a great deal of time in the water, such as the Aquatic Garter Snake (Thamnophis couchi), the Ribbon Snake (T. sauritus) and the True Water Snakes (Nerodia sp.).

While all should be given water in which to soak, the substrate must remain dry.  The aforementioned species may be kept in semi-aquatic terrariums that allow for swimming, but they must have access to warm, dry basking sites (branches over water work well).  Shy specimens that will not bask should be moved into terrestrial situations with just a bowl of water available.

Curing Blister Disease

A Northern Water Snake (Nerodia  sipedon) that I kept decades ago developed skin blisters after only 2 weeks of a largely aquatic existence.  I wrote to famed reptile man Wayne King, then curator of reptiles at the Bronx Zoo.  His advice to move the animal to a dry terrarium and provide a warm but sheltered basking site worked like a charm, and the snake’s skin condition cleared within 10 days.

Further Reading

An excellent article on the unique Aquatic Garter Snake, including habitat photos, is posted here.

Garter Snakes (Thamnophis ssp.) have long introduced aspiring herpetologists to snake-keeping and remain popular today.  A number of North America’s 30+ species are regularly available in the pet trade, and they remain the most commonly encountered free-living snakes in most areas.  Although often thought of as “beginner’s snakes”, I maintain that garters possess a unique combination of characteristics that render them fascinating additions to any private or public collection…they certainly have been a source of many of my most interesting observations.

Range

Garter Snakes of one or another species range from southern Canada to Central America, and reach their greatest diversity in the United States.

Those best suited to captivity are classified in the genus Thamnophis.  Along with ribbon and water snakes, this genus is placed within the subfamily Natricinae and the family Colubridae.

Diet

Frogs, tadpoles, earthworms, salamanders, fishes and insects comprise the diets of most species.  Several are immune to the virulent skin toxins of amphibians such as California newts, which have caused human fatalities when ingested, and toxin-protected American toads are the primary food of plains garter snakes (T. radix) and others.  Some, such as the giant garter snake (T. couchi gigs), take rodents on occasion.

Attractive Attributes

A preference for fishes and earthworms, and a willingness to accept nonliving food items (garters sometimes consume road-killed frogs) greatly simplifies garter snake husbandry, and suits them well to those who prefer not to keep rodent-eating snakes.

All bear live young and, when properly maintained, are likely to breed.  Although wild-caught snakes will bite and release musk when handled, they tame down readily…the most frequently kept species, the common garter snake (T. sirtalis), is especially docile.

Eliciting Natural Behavior

What I especially favor about garter snakes is that they can be kept in planted, naturalistic terrariums – a difficult prospect where most other snakes are concerned.

When kept so they reveal a great many of their natural behaviors – far more than is the case for large snakes maintained in bare enclosures.  A pair of garter snakes in a terrarium stocked with plants, branches, hideaways and a pool will provide you with insights into snake behavior that are not easy to come by otherwise.

A Wide Spectrum of Colors

While not subject to the intensive captive breeding efforts applied to other species, garter snakes are being kept by several breeders interested in developing unique color morphs.  Already, some spectacular results have been achieved, and more can be expected.

This is not to say that selective breeding is necessary where garter snake colors are involved.  All are interestingly marked, and a great many species sport bright colors.  In fact, a subspecies of the common garter, known as the San Francisco garter snake (T. sirtalis tetrataenia), is one of the most beautiful snakes to be found anywhere.  Unfortunately, it is highly endangered and may not be kept in the USA, but by all means try to see it in zoo collection if possible.

Individual variation among animals of the same species is the rule when it comes to garter snakes, so all sorts of interesting surprises await those who seek out these most fascinating reptiles.

Further Reading

Please see my article Keeping Snakes in Naturalistic Terrariums for some ideas concerning planted habitats for garter snakes.

Texas Garter Snake image referenced from wikipedia and originally posted by Dawson