Attracting Amphibians to your Backyard
By Myrna Pearman
Who among us isn’t delighted to be serenaded on a warm spring evening by croaking frogs or trilling toads? What child isn’t excited to be able to poke around a wetland, dipping for tadpoles or chasing frogs through tall wet grass? What gardener isn’t impressed when they see a slithering salamander?
Unfortunately, our cities are expanding ever outward, gobbling up the potholes and woodlands that once provided habitat for amphibians and other creatures. Replacing these rich ecosystems are asphalt, concrete and monocultures of lush but chemically dependent and ecologically barren lawnscapes. It should come as no surprise that our encounters with amphibians are therefore becoming increasingly infrequent.
The good news is that, despite widespread loss of habitat, there are things we—whether urban or country dwellers—can do in our own yards and gardens to attract and encourage these species. Unlike birds, which can often be enticed simply by setting out a bird feeder or a birdbath, attracting amphibians requires a more wholistic approach. Amphibians will appear and stay only if we provide them with adequate habitat—space within which they can find food, water and shelter.
A piece of bark provides a cool, dark and damp shelter for a tiger salamander. Drawing from: NatureScape Alberta.
Space—amphibians require a variety of habitat types that when linked together complete their life cycles and act as conduits to movement. They require healthy environments that provide water, adequate cover, foraging habitat and other required resources for survival. If you live in a new, denuded subdivision that is located between busy freeways, you aren’t likely to attract too many amphibians, no matter what you do in your yard. However, if you live in an older city neighbourhood that is well treed or is near a ravine, woodlot or other natural area, you should have no problem enticing them to take up residence.
An ideal amphibian-friendly water garden is ecologically balanced and is surrounded by sufficient protective cover. Photo from: NatureScape Alberta.
Because amphibians have thin, permeable skin, they are particularly susceptible to lawn and garden fertilizers and pesticides (including fungicides and herbicides). Avoiding the use of pesticides will make your yard and garden a healthier place for both you and your amphibian neighbours. Cats and dogs will also kill amphibians, so amphibians will thrive only in pet-free yards.
Food—adult amphibians eat a variety of invertebrates, including garden pests such as slugs, grasshoppers and caterpillars, so a healthy population of amphibians provides us with an important environmental service by helping to keep the populations of these pests in check.
Water—water is a crucial to attracting amphibians because all Alberta species lay their eggs in water and the tadpole/larvae stages are aquatic. In the absence of water or moisture, amphibians quickly perish due to dehydration or desiccation. The best way to provide water in an urban yard is to install a water garden. Most nurseries now stock a wide assortment of water garden supplies and have knowledgeable staff that can assist with the logistics of installation.
The ideal amphibian-friendly water garden is one that is ecologically balanced and is surrounded by sufficient protective cover. An ecologically balanced pond is large and deep enough so that it can support an aquatic food web where the pond’s water, minerals, gases, animals and plants all interact in dynamic equilibrium. It should also have a shallow area where the sun’s rays can quickly warm the water and beach areas that allows amphibians to enter and exit the water freely.
Shelter—as long as adequate cover is provided, amphibians will find their own shelter. A small boggy area installed adjacent to the pond is a good way to encourage amphibians to remain in the area. Although water gardens shouldn’t be installed in shady areas or under overhanging branches, at least one side of the water feature should be left unmowed or, better yet, planted to shrubs, tall grasses or ferns to provide shade and protective cover. These areas can be made even more appealing if leaf litter is left to accumulate and if pieces of bark or decaying wood are laid down to provide cool, dark and damp hiding spots.
Amphibians have remarkable strategies to cope with our Alberta winters. Most Alberta frog species tend to burrow under the leaf litter or beneath fallen logs while salamanders and toads tend to retreat into underground burrows. Providing an area where the leaf litter is thick and the ground dotted with fallen logs will likely provide adequate cover for over wintering wood frogs and boreal chorus frogs. Be sure to avoid trampling the snow in these areas, as their survival is also dependent on a thick snowpack.
In an effort to hasten the colonization of their yards by amphibians, some people take eggs or tadpoles from the wild and transplant them into their water garden. Natural colonization should always be preferential over transplants, as successful natural colonization will indicate the presence of adequate amphibian dispersal corridors and proper habitat that can support all amphibian life stages, especially over wintering.
Furthermore, moving the eggs or tadpoles or adults of some species is illegal under Alberta’s legislation. Therefore, such practices should be undertaken judiciously.
Regardless of the species, adult amphibians should not be collected and moved, as they usually remain in familiar surroundings and are likely to become disoriented and leave a new area as quickly as possible.
For more information about improving backyard biodiversity, see NatureScape Alberta: Creating and caring for wildlife habitat at home (available at most bookstores).