Create a Hibernaculum for Reptiles and Amphibians in Your Garden

Wildlife gardening is all the rage among gardeners today. Most of the attention goes to birds, butterflies, and beneficial insects. But an equally persuasive case can be made for enticing reptiles and amphibians into the garden.

Frogs, snakes, and lizards eat your garden’s worst enemies. They consume harmful insects, slugs, and other plant pests. Many are also food for other animals.

But while the snake, the lizard, and the toad can improve almost any garden, each is burdened by dwindling habitats. Like many other wild animals, their populations are declining.

Reptiles and amphibians are creatures from a faraway time, of wild open spaces, of countryside, of marshland, glades, and bogs. They don’t adapt well to changing conditions. They can’t survive on building sites and tarmac.

So, if some remain in the friendlier corners of your garden, you’d be wise to provide them with adequate shelter and protection. Regardless of whether you live on former reptile territory, it’s worth making your garden a haven for these wonderful animals.

Creating a Safe Haven for Snakes, Lizards, and Frogs

You can allow amphibians and reptiles a safe place to shelter through the cold of winter by building a hibernaculum. Hibernacula are small, subterranean chambers that amphibians and reptiles use to protect themselves from the winter chill.

The little, unobtrusive structure can also become a corner where solitary bees and birds can safely sun themselves.  

The word “hibernaculum” is derived from the Latin word for winter, hibernus.  Scientists argue over the semantics of whether reptiles and amphibians go into “dormancy,” “winter lethargy,” “brumate” or “hibernate.”

Most have accepted the general use of the term “hibernate” to describe the changes in behavior we observe in reptiles and amphibians in colder climates during the winter.

How to Build a Hibernaculum

Curiously, the best hibernacula are often unintended. Overgrown allotments with old plots mixed with soil, rubble, grass heaps, and other material make superb winter refuges. Tree roots, deep leave litter, compost heaps, log piles, and rock piles are also excellent over-wintering sites.

If you wish to entice lizards and amphibians into your garden, you should aim for something similar. Select a sunny spot, then dig a hole about 50 centimeters deep and 1.5 meters wide. Fill the hole with logs, bricks, fallen tree limbs, and rocks. Be sure to leave gaps in between these loose materials.

The Wildlife Trust suggests that you use drainpipes at the ground level to form an entrance into the hole. Cover the pile with 50 centimeters of soil and plant meadow seeds or long grasses over the mound to encourage summer pollinators.

Managing Your Garden Refuge

Creating a good hibernaculum is important, but your project will require suitable long-term management, as well. Try to create uneven margins around your site. Do not clear the vegetation over the mound. Instead, cut back on those verges where short grass turns into dense scrub.

Some areas may need cutting more often to prevent thistles and stinging nettles. But once suitable vegetation is established, you should cut even less.

Try not to mow your lawn in the late evening or at night. Practically all species of reptiles and amphibians move through the lawn at night. Even turtles become nocturnal during the egg-laying season, in early summer.

Consider installing a wildlife pond in your backyard. They are not too difficult to make and you don’t need a large pond if space is limited. With beautiful water lilies, a wildlife pond will bring you great enjoyment even as it provides a refuge for frogs and toads to lay eggs.

You can also convert part of your lawn into beautiful perennial flower beds, ground covers, or shrubs. An open lawn does not provide adequate protection for small animals. They occupy a rather low station on the food chain and often need to hide from predators.

Scientists estimate that 200 species of frogs have gone extinct since the 1970s. Many fear this is a harbinger for a far greater loss on the planet’s biodiversity.

In fact, some research suggests we’ll start seeing catastrophic declines in mammal, fish, and bird populations soon.

Following the rapid disappearance of various species of frogs, snakes, and lizards, many scientists now worry that these animals are the “most at-risk” among all vertebrates.

There is still time to turn the tide. Your garden can be part of the global effort to save what’s left of these precious creatures.

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