Snakes play a very important role in ecosystems. Dense foliage close to the ground offers feeding and hiding areas. Snakes overwinter in exposed bedrock, stone walls, or in earth holes filled with stones (see attached diagram). For those of you worried about attracting venomous snakes to your backyard, there is only one venomous snake in Ontario-the eastern massasauga rattlesnake. This endangered species is restricted to a narrow 25 kilometer strip along the shores of Georgian Bay, Lake Huron and Lake St.Clair.
In your backyard "ecosystem" some snakes (garter snake) may prey on your frogs or toads (another reason why frogs and toads lay so many eggs). The inoffensive red belly and brown snakes feed on slugs and snails.
Six Steps To Building Your Own Hibernaculum
1. Select a site with good sun exposure (face south)
2. Your snake hibernaculum can be sized to fit the available space, but it must de deeper than the frost line (at least 2 metres deep).
3. Snakes prefer an overwintering site that is close to the water table. Moist air ensures that snakes do not dehydrate over the cold and dry winter months.
4. Place rubble in the bottom to create many chambers for the snakes. Using construction rubble reduces the use of valuable landfill space, and reduces the need for limited supplies of quarried stone. Chambers created at different depths allow the snakes to select the temperature that they prefer, and ensures that they can climb up if the bottom of the pit is flooded with water.
5. As the pit is filled, ensure that a space or tunnel extends down into the bottom of the pit at each of three corners. Snakes use these passage ways to move to the bottom of the pit and into the underground chambers.
6. Be sure that you leave an entrance opening for the snakes at each of your three corners. Cap with an insulating layer of sand and stone.
For more information and plans to create your own snake hibernaculum contact: SNAKE HIBERNACULUM, Metro Toronto Zoo, 361A Old Finch Ave., Scarborough, ON. M1B 5K7.