Reptile & Amphibian Forums

I have 3 black rats(all seperate cages) that are all wild caught. They have been doing excellent, and at this time of year I typically brumate them for 2 or 3 months. The problem is this: where I now keep them, I am having trouble getting the temp much below 59 or 60, even with the heat off. Right now, this area is really my only option for keeping them, and I was just wondering if that is cold enough. i keep the lights off all the time, and they do seem to be in hibernation mode to me. Any thoughts appreciated, thanks!

It so happens I just had a conversation with a colleague today about hibernation temps. He reports that northern fox snakes which were monitored during winter rest selected thermal ranges between 45-50 degrees. The fox snakes had access to other temps but moved within their hibernaculum as necessary to maintain this range.

I'd say your temps are high, but constant darkness is an important factor. Many years ago, when keepers were just starting out cooling their reptiles for winter, there was a bit of a debate about whether cool temps were as important as darkness. Some keepers claimed the same results with darkness at moderate temps and others preferred temps in the mid-40s to low 50s plus darkness. I've had snakes voluntarily decide to stop moving or feeding even with the automatic lights left on as scheduled. It seems to be a seasonal response to changing climate and the approach of winter.

If there is nothing you can do to lower the temps, the point is moot. Watch your animals and see if they seem to be losing weight or declining in some way. If they don't look good, take them out and let them stay awake and feeding for the rest of the winter.

If you have a spare room you can close off, and if temps drop low enough, you might try leaving a window open and putting a fan in the window to pull cool air into the room. I live far enough north that it's bitter cold already so no problem keeping things cool--I have to be careful they don't get too cold.

If you're resting your snakes with the plan to breed them, it may be worth considering the many reports of successful breeding in collections that never brumate their snakes. I do believe that cooling improves the chances of breeding but it would appear that it's not absolutely necessary.

Most folks find a recipe that works for them, based on their facilities, commercial or not, collection size, species, etc.
Some folks who find their "success recipe" will sometimes tell you "this is the only way".
Don't be afraid to try different techniques that make sense to you.
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For what it's worth.
I cool all my North American Rats exactly the same way (except for Western Greens and Subocs). That means Florida Key's Deckert's Rats are literally brumated side-by-side my Eastern Fox Snakes.
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Temps at 60F, put down in the dark with one sliver of natural, indirect light penetrating the hibernaculum room (shed). (Measure Temps, don’t guess.)
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They normally live together and are put to "sleep" in pairs the week after Thanksgiving.
They come out around the end of Feb.
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Every cage breeds every year, unless I choose to separate them.
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South Florida animals tend to double clutch.
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IMHO the five most important ingredients for success are:
1. Photoperiod is almost more important than temp. (And physical disturbance kept to an absolute minimum.)
2. When coming out of brumation, females particularly need to be pumped with food.
3. When males come out of brumation, avoid overheating them in any way.
4. Animals have access to fresh water during brumation.
5. Temps during brumation just need to be cool enough to put them into inactivity. (I use the word loosely here, because it is not unusual to see them occasionally cruising their cages in the dead of winter.
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Animals kept this way are every NA Rat variant listed in the 1958 issue of Conant’s Field Guide and a few kings.
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As an aside, I brumate holdover hatchlings for no other reason than to give me a break for two months!!!!!!!
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Good luck.
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Regards, Bill McGighan

He has all the key elements in place; darkness, temps that work for him, water available during brumation, etc. And, perhaps most important, his success speaks for itself. About the only difference in my collection is that I go for temps around 50. Even at those temps, my snakes move around during brumation and drink water when thirsty.

I use a wine cooler with an external thermostat (Ranco 111000). With this I can get temps from 45-65F with accuracy of plus/minus 1 degree F.

-Chris
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Christopher E. Smith
Contact
Captive Bred Herps
Wildlife Research & Consulting Services, LLC

I like the Ranco 111000. I've had two failures (one open and one shorted) over 10 years. Not bad considering I run it to control a maximum current load.
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I wire them in tandem to avoid thermal runaway.
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A discrete (on/off) controller is fine and I set the deadband to only 1 degree F.
I also keep a redundant heater with a setpoint of 3 degrees below the primary.
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Regards, Bill McGighan

Thank you guys very much for the info, after reading that I would say my hibernation area is working fine. Thanks again!

>>I have 3 black rats(all seperate cages) that are all wild caught. They have been doing excellent, and at this time of year I typically brumate them for 2 or 3 months. The problem is this: where I now keep them, I am having trouble getting the temp much below 59 or 60, even with the heat off. Right now, this area is really my only option for keeping them, and I was just wondering if that is cold enough. i keep the lights off all the time, and they do seem to be in hibernation mode to me. Any thoughts appreciated, thanks!

Can't argue with Bill's success, but I do things a little differently, because of my location and facilities.

I live in southern AZ and have two Herp Rooms. My brumating snakes are on the Back Porch (AZ Room) and my active snakes are in my Herp Room (bedroom). The temps on the Back Porch usually are in the mid-50's, but will vary from high 40's to mid-60's, depending on the daily weather patterns, or what kind of front is over our area. If we get temps in the 60's everyday for over a week, I might have some snakes that might want to take a small meal. If that happens I put a heating element under one end of the cage for digestion. It also depends on what species and how hardy they are. I have about eight species of rats and kings.

In my Herp Room indoors the room temp varies bt. 68 and low 70's usually. I often use a space heater to warm the room to the high 70's for part of the day. I also use a humidifier, as it gets very dry here in winter. The snakes are doing what I call a "partial brumation." I think their metabolisms slow down and they don't eat nearly as often, maybe once every two to three weeks. When they do I put the UTH in place for digestion. If I decide to do a harsher brumation with them, I might turn off any heat completely for 4 to 8 weeks. In Jan and Feb temps likely won't get out of the mid-60's.

As far as the black rats go, I don't know their size, but if juveniles I would probably think about keeping them active, although brumating wouldn't hurt them, especially if it were only 2-3 months. If adults, 60*F. is a little warm for an extended brumation, but it probably would work for a couple months. You could always offer a food item after every 3 to 4 weeks to see if they are interested in eating. After 12 weeks at 60*, I'd bet they'll be really hungry.

In summary, with everything in place, steady 60* temp, darkness, and proper cage accessories, water, etc, your snakes shouldn't have any trouble surviving. Under these conditions I would check on the snakes at least every couple weeks. Maybe you could even weigh them and monitor their weight. Let us know how it goes.

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