Reptile & Amphibian Forums

I'm building a hibernaculum and wanted to know what everyone thinks is the best substate to use to hold warmth. I plan on using a mixture of grass clippings, leaves, and dirt. Also what are the most important elements in creating a hibernaculum, I'm worried about the soil around my house it becomes very hard and clay like after about a foot. The way I designed the hibernaculum is a rubbermaid trash can on a 45 degree angle into the ground. I cut the bottom out so it drains. Here is a picture, I'm a litte worried about water building up if it can't drain properly. Is it real bad if the substrate gets fairly moist.

It's important to know where the average frost line is in your area, my area it is about 4 ft. so I'm not about to dig a 4ft pit and I wouldn't expect my turtles to dig that deep in clay either, so I bring them inside, but maybe your frost line is 8" or whatever but my point is that I would have that as deep as your frostline is or run the risk of frozen boxies, and drainage is very important, rotting, drowning, not to mention air pockets are good insulators. To answer your question straw is a very good insulator and it drains well.

Chris,
Is this the first time you've allowed them to brumate outdoors?

I may not be telling you what you want to hear because it seems like you've put a lot of work into that so far. I'd be concerned that the plastic garbage can and the PVC liner you have laid out will collect and hold in too much water, as you feared. While living in NJ, I would provide a large pile of leaves and pine needles. The pine needles are a good addition because they seem to make the mixture collapse less throughout the winter. Regardless, I would usually add some leaf litter mid-winter. Overall, the pile stayed about 2 feet high. The soil below had leaves and needles turned into it. In NJ, the turtles would only ever burrow 8 inches at most into the soil below...at an angle. I've recently found that the turtles seem to appreciate logs laid horizontally underneath the compost pile. If you want them to be able to snuggle under something, I'd recommend logs in lieu of something artificial.

I have never made much of an effort constructing a hibernaculum. I simply make a very large pile of compost and make sure that it stays piled high all winter. I have NEVER lost a turtle to brumation, and that includes Florida box turtles about 600 miles north of their native range.

In my humble opinion, keeping box turtles outdoors, outside of their native ranges, through a winter does deserve some extra thought. In their native range, it is usually a piece of cake with a healthy turtle.

Hope this helps. Good luck.

Ken, I scrapped the other hibernaculum, I'm too worried about the drainage, my soil is too clay like at the base. Instead I dug a trench on a 45 degree angle, with the deepest portion being 2 feet. On top of it I put a piece of plywood as a roof, on top of everything I'm piling leaves to about 20 inches. Within the trench what do you think I should put? I don't want to use my soil because it becomes to hard. I may use a mixture of peat, my soil, and pine barrens soil with pine needles. What do you think I should use in the actual trench? Also I should note these turtles I'm hibernating were just rescued from a 125 acre woods about to be bulldozed this winter or spring....I did not want to relocate all of them until next year when they can have a proper period of time to acclimate. I'm not sure why I'm worrying since I have one spot where I've witnessed turtles only digging as deep as the top of there shell......I just want to ensure they come out alright.

Great points Kensopher, I think if I were to attemp to brumate my turtles outdoors I would use straw, pine needles, mulch,compost, or leaf litter, or a combination of those well draining organic materials. I think that most wild boxies would either go down an amimal burrow as in the case of ornates or dig deep into a sandy bank, or burry themselves in deep leaf litter in a forest or woodland. The added benifit of using organic materials is that, if they start breaking down in the fall (aka composting) that process will provide slow constant heat. As anyone who has composed in the North can attest too, if you turn your compost pile even in the dead of winter, tons of steam will rise off of it.
Do you have any compost or access to some, Chris?

No I don't have access to compost. What I was going to do is use grass and leaves that come out of our mulcher. I've found this holds heat very well. I was going to use a combination of this, with dirt and peat. Most of the boxies I have observed in the wild just dig into areas of heavy leaf cover, and only go a few inches down.

If I were you, I would take it easy on the quantity if grass clippings: add enough grass and you'll have enough nitrogen to start that compost heating up, which isn't really desirable if you think about it.

"The added benifit of using organic materials is that, if they start breaking down in the fall (aka composting) that process will provide slow constant heat. As anyone who has composed in the North can attest too, if you turn your compost pile even in the dead of winter, tons of steam will rise off of it."

But you don't really want to produce significant heat for the turtles: the objective should be to provide enough insulation to protect them from freezing.

Here's a rough sketch of the way I made one of the hibernacula here, followed by a photo taken toward the end of the winter:

Chris, to answer your questions above...I think that Steph's sketch is perfect.

There are two major different types of compost pits...hot and cold. To create a hot pit, you have to add "dead brown stuff" and "recently living green stuff" along with dirt. The dirt supplies the bacteria and fungi necessary to jump start the process. For this reason, I don't add much green stuff. I don't want it to get hot because it will keep them active. I wouldn't bother hauling sand from the pines...you'll be fine with any of the things that you already mentioned.

Did the turtles come from an area close to White's Bogs?

Love that cat picture!

Thanks guys the new hibernaculum looks exactly like Steph's drawing.

Ken, no they didn't come from that area(didn't that spot get developed already?). They came from a plot of land in camden county were the new virtua hospital is to be built. The site is loaded with very common jersey herps, many of which I'm frantically trying to relocate.....its sad because the boxies there are exceptionally beautiful. I'm just hoping the land is leveled until next july or so.

I have clay soil here in Central VA, too, and I heavily amended the soil in the hibernacula with peat and leaves the first year, then just leaves every subsequent year. I have found that, by mounding more leaves over top of the log 'roof', the whole arrangement will shed excess water during a heavy downpour.

I also found(by accident) that there is an added bonus to this design: in the summertime, the turtles have a nice shaded cave to hang out in, and they often find a snack in there due to the fact that slugs and crickets, etc., take refuge there as well.

Part of the land got cleared, but the bulk of the land is still (as far as I know) locked up in legal battles with local homeowners and the Pinelands Commission. There is an incredibly dense population of box turtles there, and I really believe that they can "migrate" to the surrounding areas when development moves in. There are still large tracts of land around this area. I see turtles fleeing from construction down where I live now (an area with one of the fastest population growths in the world), but they always have to flee into the roads because the habitat is so fragmented.

If your soil is hard clay, a hibernaculum like the one in the diagram has potential problems. If you dig a bowl-like depression out of the clay and fill it with softer soil/leaves/pine needles, and you get a hard rain, the water will accumuate and lay in that depression and not drain much faster than if you used the plastic trach can. It's the same concept as planting a shrub in hard ground. You have to actually build up the soil above ground level to allow for proper drainage. I'd forget about the hole altogether and pile some softer soil (top soil mixed with peat), no more than 8-10 inches, and just mound oak and maple leaves mixed with pine needles right on top. They'll crawl right into the pile and dig in as far as they need to. I do this with my boxies in an enclosure on my back porch every year. I don't have to worry about the drainage because the porch is covered. If you pile enough leaves and needles, you don't even need to worry about the soil, they'll be fine under the leaves. Just hose down the leaves really well and make sure they don't dry out completely during the winter.

I never said anything about adding green stuff and hot composting, and to really get "hot" composting you have to turn it and add water often. And yes a little heat at below freezing temps is desirable, and yes even your leaf pile is organic and breaking down and providing constant low amount of heat. That's why I suggested adding compost, because it's not hot anymore, it's already mostly composted!!!, that's why it's called compost and not organic materials for composting.
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1.0 pastel ball python
0.1 mojave ball python
0.1 normal ball python
0.2 3-toed box turtles
2.3 eastern box turtles
0.0.5 3-striped mud turtle
1.0 northern diamondback terrapin
2.1 tiger salamander
1.1 red-sided garter
1.0 anerythristic red-sided garter
1.1 Iowa snow plains garter
1.1 Het butter stripe cornsnake
0.1 anerythristic motley cornsnake
1.1 Blue garter (Puget Sound)

I wasn't responding directly to your post. Chris wrote that he was going to add grass. I agree, a very low and slow release of heat can help and is probably very similar to what they experience in the wild. I just think that Chris should avoid making the pit too hot.

And I wasn't attaching your post either Bud, I'm on your side and everyone's here for that matter,we all have a common goal here. I was just clarifying about the grass too, we are totally in agreement, I also do think the above post has a valid concern for the hole in clay becoming a "mini-pond". I also hope you are not offended by the above post about the hibernaculum pic. I'm just making a joke, trying to make you laugh, that's just how I roll man, I try to have fun with my life because you only get 1 and tomorrow may be too late
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1.0 pastel ball python
0.1 mojave ball python
0.1 normal ball python
0.2 3-toed box turtles
2.3 eastern box turtles
0.0.5 3-striped mud turtle
1.0 northern diamondback terrapin
2.1 tiger salamander
1.1 red-sided garter
1.0 anerythristic red-sided garter
1.1 Iowa snow plains garter
1.1 Het butter stripe cornsnake
0.1 anerythristic motley cornsnake
1.1 Blue garter (Puget Sound)

Absolutely no offense taken. As you, I meant no harm.

Cheers.

Thanks! Clovis the cat rules the neighborhood....

Thanks guys for all the tips.....hopefully they will get through the winter ok.