Chris Petersen has a firm belief that if you build it, they will come — in this case "it" being a water feature and "they" being frogs. Petersen is co-chair for Partners in Amphibian and Reptile Conservation (PARC), a network for anyone who has an interest in conserving and managing amphibians and reptiles and the habitats in which they live.
"In a reasonable suburban environment, with a little bit of natural habitat scattered in, certain species such as green frogs, bull frogs and leopard frogs are just great at finding gardens with non-chlorinated water features and setting up residence, especially for breeding," said Petersen, who is also a Navy biologist. Frogs are often first, while toads, salamanders and other amphibians come next. At some point, he added, birds or animals that prey on amphibians will likely show up as well.
Here are some ways to create a garden that will attract amphibians plus tips on what to expect, how to know if salamanders, newts and other secretive creatures have found their way to your garden and how to identify the amphibian species you're likely to see.
How to attract amphibians
As with many aspects of the garden, a water feature can be as elaborate or as simple as your budget and time allow. The real key to gardening for amphibians, emphasized Petersen, is to have nearby a habitat where amphibians are already living.
"Without any natural habitat around your home or neighborhood, these animals have a long way to go to get there," emphasized Petersen. "It may take them a while to do this, or they may not do it at all. So, you must consider what you see in your neighborhood. If you see frogs and toads, then yes, it’s very likely that if you build it, they will come."
And if you build it, there are other things you can do that will enhance the appearance of the water feature that will also attract amphibians and entice them to stay, like providing natural or artificial cover objects under which amphibians can hide and stay cool.
A natural cover object might be a rock, a log or a tree that’s fallen over or even a branch laying on the ground. "A lot of amphibians, such as salamanders and frogs, like to seek cover under those objects," said Petersen. "Toads will seek refuge there during the day. Leaving fallen items in your garden will provide cover objects for those animals and will certainly go a long way making your garden more attractive to amphibians."
Examples of artificial cover objects include plant containers, rain barrels or even a flipped-over wheelbarrow that has not been moved in a while.
Native plants will also help draw in amphibians and keep them around. Amphibians are insect and invertebrate eaters, and native plants will help attract pollinators that are natural food sources. "I'm always a fan of planting natives," said Petersen. "Amphibians are adapted to living in habitats where there are native plants, and they would be an extension of their natural habitats in your garden."
How to measure your success
You’ll be able to measure your success in seeing frogs and toads because they tend to be visible or heard in the garden, especially at dusk and the early evening. Another good time to see them, said Petersen, is during spring and early summer rainy spells. They become very active then because this is typically the time of year they mate.
Because many frog and toad species in general are most active during the night, you’ll know if you’ve attracted them to your garden because you’ll be able to hear them after the sun goes down. If you’re wondering why frogs and toads make so much noise at night, Petersen points out that this is the result of their breeding biology. "Male frogs or toads vocalize to attract a female mate. When the weather conditions are just right (usually a rainy night), many male frogs and toads of the same species, or even several different species, will call at once forming a chorus."
Petersen also pointed out that certain species of frogs will call out during the day. "Just yesterday up here in North Carolina we heard cricket frogs calling during the day from a little water hole nearby," he said. "Some tree frogs are also vocal during the day and you can hear these as well."
But what about more silent and secretive creatures such as salamanders? How will you know if they are there? "They are not commonly encountered unless searched for," Petersen acknowledged. "The way I survey for them is to roll over rotting logs, look under rocks or use a dip net in a wetland."
Certain species are more visible than others, he added, citing eastern newts as an example. "You’ll see eastern newts in the water during the day. They come up to the surface frequently, so they are pretty easy to see. But most salamander species are very secretive, and you may not know they are there by just walking around your garden. A lot of those species will breed in late winter and early spring, so you may have an opportunity to see one then in your garden water feature." The water is a place to look for them then, he said, because that’s where several species of salamanders lay their eggs. Other species however are completely terrestrial with no aquatic life stage. Eastern newts, he added, have both an aquatic stage and a terrestrial stage.
How to identify amphibians in your garden
If you see amphibians you can’t identify and want to know what species are in your garden, Petersen recommends visiting websites of state wildlife agencies, universities or herpetological clubs. "Most state agencies have a herpetologist, and part of their duties is to interact with the public and help identify species that people encounter in their yards," Petersen said. "Private clubs are also excellent resources and tend to have lots of pictures and great information about various species that help people identify what they are seeing."
The PARC network also has some excellent resources Petersen said home gardeners might find useful in creating amphibian and reptile habitat and surveying for these species. Two in particular are the Habitat Management Guidelines documents and the Inventory and Monitoring Guide. "There are five Habitat Management Guidelines organized by regions of the United States," Petersen said. "They go into detail about how to manage landscapes to make them more favorable for amphibians and reptiles. If you are someone who wants to manage your property to support populations of amphibians and reptiles, these documents are excellent tools."
The PARC Inventory and Monitoring book provides an excellent resource for biologists, land managers, consultants, and particularly those who are not experts in amphibians and reptiles, to understand how to survey for these species in their geographic area of interest.
What he finds most interesting about the PARC network and website, though, is how it provides a forum to connect people who are interested in reptiles and amphibians and allows them to share information and get involved with others who have a passion for these species. "It’s really about connecting the dots for people who have similar interests." To join, visit the PARC website.
What if you don't live near an amphibian habitat?
Unfortunately, said Petersen, it becomes much more challenging for people who don’t live near amphibian habitats to attract them to their gardens. One reason for this is that the diversity of amphibian species is low in certain habitats. A second is that the distances are probably too great for native amphibians to traverse, no matter how enticing your garden might be for them. However, he added, do not give up hope. Amphibians are excellent migrators.
Regardless of where you live, though, Petersen doesn’t recommend ordering amphibians online. "Amphibian ordered off the internet will not be adapted to the environmental conditions where you are releasing them, so they likely will not thrive there." Also, he said, you may be introducing animals that have diseases.
"Amphibians are going through massive declines throughout the world, and one of the causes is diseases. There is a species of fungus that grows on the skin of frogs and toads that has caused significant population declines and has even made certain species extinct. So, you never want to introduce animals you have ordered off the internet into your garden because you could be accidentally introducing diseases into the environment that would threaten native populations if these animals migrate away from your garden and survive."
Lastly, "You may be accidentally introducing an invasive species into an area," Petersen said. Invasive species can be predators to the native species and they also compete with them for resources such as food. An excellent example of this, he pointed out, is the American bullfrog. This is one of the worst (most successful!) invasive species on the planet, and has been widely introduced into many parts of the world, including North America west of the Rocky Mountains, according to Petersen. American bullfrogs have been implicated in the declines of multiple amphibian and reptile species across the globe, he said.
A success story
Some 10 years after they began collecting large rocks to give a natural look to an artificial stream that cascades into a pond in front of their home, Constance and Michael Johns have almost finished their long-planned project.
It took them a decade to complete the water feature because Constance had been on dialysis for six years and on a waiting list for a kidney transplant. She found a donor through a website she created, and that helped inspire the couple to turn their dream into reality.
It didn’t take a pair of frogs nearly that long to take up residence in the new amphibian-favorable digs. They moved in while Michael was working on the final stage of construction.
"I can’t imagine where they came from," said Michael, as a visitor startled one of the frogs and it leapt into the pond and disappeared. "That was the small one. The bigger one’s under the waterfall, and he is really big," added Michael, emphasizing "big" with a drawn-out, folksy drawl.
That the frogs found the water feature doesn’t surprise Petersen. Even though Constance and Michael live on the bustling northern side of Atlanta in the close-in city of Brookhaven, almost in the shadow of a busy hospital complex and just out of earshot of traffic from two often-clogged interstate highways, their home is on a quiet street in a wooded neighborhood. A nearby spring-fed creek trickles through a ravine behind their house.
It's just proof that if you build it, the amphibians will come.