Garter snakes and generating heat...

[Zephyr]

I've thought about this for a bit, but only recently did I see any proof.
Last weekend was relay for life here, so I brought Fatty as part of a reptile "room" fund raiser. It was about 50 (F) out in the morning, but I noticed that without a heat source Fatty was still very active. After a while the temps went back up then back down to 50, so I had my parents pick up the animals. My mother recalls picking Fatty out of her cold cage and saying that Fatty was incredibly warm. So, for this year's science fair I'm thinking about doing a project on whether or not garter snakes can generate their own body heat in suitable amounts. Has this been tested before? Is it outright true or false?

[adamanteus]

I'll put my head on the block and say 'totally false'. But they are very cold tolerant and can remain active at much lower temperatures than most other reptiles.

[Snake lover 3-25]

but what about when they eat??? won't all of the energy that they are taking in and using on digestion generate heat???

[adamanteus]

but what about when they eat??? won't all of the energy that they are taking in and using on digestion generate heat???

Basically, no.

[aSnakeLovinBabe]

no. reptiles do not use food energy to generate heat like we do. that is why they do not need to eat every day like us, because where as MOST of our food energy goes to keeping our bodies a stable temperature, they do not need any energy for that because they allow mother nature do it for them. It takes an unbeleiveable amount of energy to keep warm blooded animals, well, warm! That is why mammals and birds eat multiple times in the same day, where as fish, insects, reptiles and amphibians can easily go days without flinching.

As for garters generating body heat, I would say nope. It's a nice idea, and may make a good project topic, but I think you will find that maybe he felt warm because your hands were possibly, slightly chilled? I have had that happen before. By curling up when alone, and grouping up together as we all notice they like to do, they most likely HOLD heat for a little longer, (and that's probably why we lift up boards outside and find three of them all on top of one another under a huge board) but unless they are vibrating their muscles like some pythons do to incubate their eggs, they are not generating any heat. I can't see how snakes generating body heat would go scientifically un-noticed for this long. And even if they were vibrating their muscles, I could not see that amounting to any noticeable factor in such a small snake.

I will agree with james, that garters remain active at much colder temperatures than some other snakes. But I will say that the same is also true for both cornsnakes and certain kingsnakes. It probably a "it's in their blood" type of thing. Most garters come from areas that experience frigid winters, and then spring and fall temperatures that are ALL over the place... warm then hot then cool then cold and all over again, sometimes within the same week! Most pythons and boas, not so much. Many of them come from places where it's at least semi-warm, all of the time, and tehrefore, are not able to tolerate cooler temps like their hard-headed colubrid friends.

[adamanteus]

Garters (all reptiles) are by definition ectothermic... they regulate their body temperature via outside sources (sunlight, shade, heat-mat, water etc). They are not 'cold blooded', 'cold blooded' is a misnomer, they simple do not create their own heat internally, but rather get it elsewhere.
It is this ability that makes them so successful in colonising some of the most inhospitible places on Earth. Being ectothermic allows them to brumate (or aestivate) for such extended periods, it allows them to go without food for such extended periods. We're they endothermic, like mammals, they would be.... well, mammals!

[Snake lover 3-25]

but what about bears and other mamals that HIBERNATE!!!!

[adamanteus]

Bears and other mammals hibernate for a comparitively short period compared to some reptiles, and survive by maintaining a raised body temperature by burning off fat reserves built up during the warmer months. When a bear comes out of hibernation it has lost a lot of body weight (due to heat production). A snake coming out of brumation will have lost very little weight. It's a different process.

[adamanteus]

Yeah. Everything Shannon just said!

[Snake lover 3-25]

wow shannon you REALLY know your stuff!!!!!! thanks!!!well... now i know!!!LOL