With the Grain
Box Turtle Habitat
Cold weather forces box turtles under cover, or underground. Preserve areas with mature trees and soft, loose soil. Remove weedy plants, and reduce human activities. Let leafy boughs lie where they fall, and expand brush piles during the growing season.

For more box turtle stewardship guidelines, see Habitat from Humanity.

I need a safe place to settle for the winter.

During warmer months, box turtles thrive in nearly any cover, at least temporarily. They may spend a day on a dune, then a week in a wetland, then a fortnight in a forest. However, overwintering sites must minimize freeze/thaw cycles and maintain stable humidity. This requires certain soil conditions or vegetative cover.

The best cover can appear after a thunderstorm: a fallen tree (or very large wind-toppled branch) with leaves attached. Don't move branches or adjacent ground litter; let autumn leaves collect. Ideally, the limb will be stiffly branched, or fall against a neighboring tree. Then, part (perhaps the size of a large tabletop) lies darkly and solidly on the ground, while part is suspended slightly to permit slow ventilation.

In fall, most turtles seek out such a windfall, even if it's small or shallow. They enter, then 'dig' a winter burrow, descending from two to ten (or even more) inches below ground surface. They back into soft soil, alternately opening and closing the rear shell, then sliding or pushing backward into the resulting cavity.

The safest soil is loose and permeable, topped with both decayed and fresh leaf litter. Some animals work through heavier soil, though less deeply. One benefit of a brush pile may be that it encourages invertebrates and small mammals to churn and loosen the soil beneath. Digging is easier, and good drainage assures moisture, without pooling of water.

Rearward burrowing can not penetrate a mat of grass or fibrous roots. (A brush pile also helps by smothering small plants.) Good conditions occur under mature trees, with few or no understory plants. Overstory oaks or beeches seem best. To improve the odds, remove small seedlings with shallow roots that may disrupt burrowing. The greatest offenders in this region seem to be ash (Fraxinus), cherry (Prunus), and buckthorn (Rhamnus)--a weed for many reasons. Ground trailing vines are trouble, too.

You may expect a box turtle to reuse the same wintering spot year after year. It saved their life before; they'll be back. Human activities that compact the soil must be minimized in these life-saving winter yards. Stop leaf raking or burning, wood hauling--even foot traffic. The only reasonable activity is removal of seedlings and weeds that may themselves pose a threat.

You can build a great wintering brush pile yourself easily. Site selection is at least as important as the pile itself. Think Goldilocks: not too much, not too little--but just right. The list of criteria is detailed, but find any two or three together and you have a good site. If all these criteria co-exist, odds are the site is already frequented by box turtles in winter.

Start along the north side of a clearing, or, if necessary, the east side (late fall afternoon sun is a welcome treat). Work especially where large trees line the clearing edge (which tend to regulate both temperature and humidity). If no clearings exist, create some for future years. In the meantime, build piles beneath a large woodland tree or very large shrub. Their shade will have reduced grasses and woody stems that hamper burrowing.

Choose a spot with moderate air drainage--neither an exposed hilltop nor a low pocket. The soil must be relatively dry. Available water encourages ice formation, which can kill. However, exploit natural barriers of shrubs or tree trunks by selecting the moist side, away from prevailing winds. Wind-induced drying also is stressful. Remember Goldilocks.

This location will feel like a good spot to hunker down for the winter, even to you. Scope several sites 80 to 100 feet apart, perhaps further, so all the locals will have a chance. If time or resource constraints limit the number of piles, distribute them evenly over as large an area as the turtles seem to use. They will seek out the piles over some distance, especially when visible across a clearing.

For the pile, start with moderately large sticks several feet long, crisscrossed to permit some air movement. If possible, lean one in the notch of a scrub tree a few inches above ground. The pile should not be held off the ground, just a bit open here and there. Keep in mind that snow is your friend. Your goal is to provide as many places for snow to catch as possible, while providing alternative insulation if the snow fails.

Add layers of branches, especially with leaves attached, until you're tired of cutting. (If you have only bare branches, alternate with layers of grass or weeds you've pulled.) Seriously, keep cutting until you run out of energy. Two foot deep is good, four feet deep seems better. Five feet across is OK, ten feet across is great. Just keep the layers loose and random: no stacking! The more opportunity to get lost under that pile, the greater their survival rate.

By the way, don't be surprised to find turtles chilling out in the abandoned den of a badger, fox, coyote, or groundhog. Some will choose a cockeyed woodpile, where mice and moles have loosened underlying soil and moist leaves have accumulated. Long-moldering, humus-covered piles of very large rocks may serve the same purpose. However, don't start with theories about concrete blocks and sewer pipes. Concrete and sewers are why turtles need help in the first place.

For more box turtle stewardship guidelines, see Habitat from Humanity.

With the Grain - - Box 517 - - Mattawan, Michigan - - 49017-0517 - - wtg@wtgrain.org

...head home now!
Reason to Plan Preservation Spoken Softly Waiting to Die