Category Archives: Mitigating Hazards to Wildlife

Wildlife and Swimming Pools: Can They Coexist?

Each year millions of animals hop, crawl, slither, fly or fall into pools. Most don’t make it out. With a little creativity and the help of products that provide escape routes, can we have our wildlife and our swimming pools too?
Image of swimming pool gate from patio garden
An abundant garden feeds and shelters hummingbirds, bees, frogs, squirrels, rabbits and many other creatures outside our pool (above). Tree frogs perch in treetops but are just as content in the potted plants we move from the basement to the patio each spring (top).

During the warm season, our place is always hopping. American toadlets leap around the downspouts in early summer, diving into surrounding leaf litter when we pass by. Tree frogs climb high into the sassafras grove and perch on potted rubber plants on the patio, the mini kings of our jungle. Wood frogs pop up unexpectedly in the shade of an old ash tree, reminding us even in the solitary moments of gardening that we are never truly alone.

Image of wood frog in garden

Image of Toadlet on downspout2
Wood frogs keep us company as we meander about in the shade garden, while baby American toads find habitat near the downspout. (Photos by Nancy Lawson)

These are the happy moments, the times when I know our home is a haven for many more species than just my own. In the 17 years my husband and I have been here, the once sterile property with two acres of lawn and a smattering of invasive shrubs has come alive, a place so packed with trees and hedgerows and wildflowers that we never know who will decide to start a family here next.

Image of box turtle in swimming pool
When a box turtle wandered into the pool, he used the pool cleaner connector as a life preserver. Animals in need of sloping sides to climb out are stymied by the ninety-degree angles of pool walls.

But on this patch of paradise where all animals are welcome, there is one spot I wish no wild resident would go: our swimming pool. In backyards across the U.S., such refreshing oases for humans can become death traps for frogs and other animals. Without the sloping sides of natural ponds and stream banks, the clear water invites visitors in but offers no way out.

The problem receives so little attention that even wildlife biologists like Rich Mason have been surprised to discover the extent of the harm pools can inflict. “As a kid, swimming pools were a source of great joy,” says Mason, now 56. “And then when I got a call in 2004 from our good friends who are basically around the corner from our house—they had just built a swimming pool on a wooded lot, and they said every single day there were dead frogs in the pool—I couldn’t believe it.”

Even if each in-ground pool killed one frog per season, the cumulative death tool would be at least 5 million. But “it’s way more than that,” says Mason.

Close to 10 million pools, about 5 million of them in-ground, dot backyards and public spaces across the country. Even if each in-ground pool killed one frog per season, the cumulative death tool would be at least 5 million. But “it’s way more than that,” says Mason, especially when considering the many sensitive habitats where pools exist: near the wetlands of Florida and South Carolina, in wooded regions of New England and Canada, and across dense suburban areas of California, where many wild species are considered threatened or endangered.

In Mason’s friends’ pool alone, 53 frogs were found in a single morning after a warm, rainy night. The impact was overwhelming for Mason, whose job with the U.S. Fish and Wildlife Service involves restoring wetlands degraded by croplands, timber harvesting and roadways. The discovery of another major killer of aquatic wildlife was surprising enough, but the bad news didn’t end there: “I went on the Internet, and there was literally no information,” he remembers. “I figured that some scientists would have kind of studied this, but I couldn’t find anything. I was shocked.”

Image of frog on Frog Log in swimming pool
Since its invention 13 years ago, the Frog Log has become a staple in swimming pools of people who care about wildlife. It’s made by Swimline, after Mason tracked down the company at a trade show to seek help. “I quickly realized that if I really wanted to save more animals, someone else was going to have to manufacture and distribute it,” says Mason, who has a family and a day job as a wildlife biologist. (Photo courtesy Rich Mason)

Mason sprung into action, developing an easy-to-use but profoundly effective flotation device called the Frog Log; his early prototype was so successful it saved 47 American toads and three green frogs during a three-week testing period. Mason’s motivation was simple: “I’ve always rooted for underdogs, and our natural systems are underdogs.” In the years since the first iteration of the Frog Log, countless frogs, toads, mice, chipmunks, bees, wasps, bats, and endangered snakes have climbed the mesh ramp to safety in pools across North America and beyond. The Frog Log even saved an armadillo in Florida who clung to it until the pool owner could transport him to dry ground. “What we’ve determined is if you give animals a way out of a swimming pool, most of them will find it,” says Mason.

Image of baby toads rescued from swimming pool
Three months after we moved into our home and the snow melted, we discovered the cover of our new pool was a breeding ground for toads and frogs. (Photo by Nancy Lawson)

When we bought our house, we hadn’t even seen the pool yet. It was a wintry March, and the backyard was covered in snow. The April thaw revealed a flat blue cover pulled tightly against the walls, and May breeding season revealed something else: baby American toads—hundreds of them who’d grown up in the swampy waters atop the cover—looking desperately for a way out, only to run up against a 90-degree angle. Friends and I spent many hours scooping them out and placing shallow trays of the brackish water nearby, hoping our tiny charges would visit those instead.

Image of mating toads in swimming pool
The current pool cover stretches over the side so the offspring of these romantic spring trysts can climb out. (Photo by Nancy Lawson)

Since then, we’ve traded that original pool cover for one that slopes over the edges, providing easy exits. In the spring it becomes a kind of makeshift vernal pool, inviting amphibians to start getting randy, and we remove the cover only after the resulting baby toads have grown old enough to hop away to their new life.

Image of mouse on frog log in swimming pool
The blue cover has worn off one of our older Frog Logs after years of use, but that’s fine with this mouse, who found his way out and began catching insects to nibble. (Photo by Will Heinz)

Still, I have a love/hate relationship with our pool. It’s been the scene of wonderful gatherings of family and friends looking for relief from the sweltering Maryland summers. The sound of children splashing and laughing as they learn to swim has been music to my ears. Bats swooping down for a sip in the evenings delight my husband, who hides under the diving board for optimal viewing. But while we never lose frogs thanks to the Frog Log and have seen mice climb up its ramp to safety as well, every summer my husband finds at least one dead mouse. And insects—especially some water-loving beetles—are drawn into the pool in significant numbers at certain times of the year. Once a box turtle wandered in and lay on the plastic tubing of the pool cleaner as if it were a log. Though she ambled on her way after my husband quickly carried her out, I worried about her exposure to the chlorinated water.

Considering all these lurking dangers, is filling in our pools the only solution? I posed the question to Mason. He’s a man with a lifelong affinity for animals that was first cultivated during camping trips, weekly viewings of Jacques Cousteau and Wild Kingdom, time spent nursing injured wildlife in his backyard, and a mom who taught him to be kind. But he’s also a reasonable person who knows the human species well. “I don’t think we should be advocating that,” he said of my down-with-pools idea. “That’s not going to get us in good graces with anybody.”

Can we have our humane habitats and our swimming pools, too? It’s still an open question for me.

As I think about my husband, I know Mason is right. Will is just as devoted as I am to helping the wildlife and has protected and nurtured many animals in our growing habitat over the years. But the pool is a source of exercise and meditation for him, a continuation of a lifelong routine he started as a child at his family’s rural home. I’d be lying if I didn’t admit to my own sense of relief and therapy in its calming waters, too.

So what is a wildlife gardener to do? Can we have our humane habitats and our swimming pools, too? It’s still an open question for me, but the following tips can help greatly mitigate the dangers.

Image of bee on frog log in swimming pool
Especially in large pools, multiple Frog Logs give animals a better chance of finding a quick way out. We also leave pool floats and noodles in the water to help bees, dragonflies and other insects. (Photos by Nancy Lawson)

Image of Dragonfly on pool float

Create an escape-route highway. The more Frog Logs you add, the more animals you’ll help, especially if your pool is large. Typically frogs circle the perimeter looking for a way out, but I’ve rescued crickets who repeatedly swim up against the same patch of wall, apparently looking for a slope to climb. Small mammals may search along the edge for an escape, but they are less adept swimmers and exhaust themselves more quickly than frogs do.

Multiple ramps provide quicker exits, saving these creatures from drowning and prolonged exposure to chlorine, the long-term effects of which are still unknown. Even if an animal escapes, will he later die from chlorine poisoning? It’s not clear, says Mason: “I know of no research that has happened.” While bullfrogs sometimes take up residence on Frog Logs, their diminutive counterparts may be more negatively affected. “Just anecdotally, we’ve noticed that the smaller animals are much more susceptible to the chlorine and that they don’t last nearly as long.”

Put the filter to bed. Turning off the filter at night is “one of the most important things you can do,” says Mason. Many animals are crepuscular (active at dawn and dusk) or nocturnal, and if the filter is running, they may get swept up into the skimmers before finding a Frog Log. Filters are generally most needed during the day anyway, when algae and residue from body oils and lotions can accumulate.

Image of spider on Critter Skimmer in swimming pool
Our new Critter Skimmer has given safe passageway to insects swept toward the skimmer baskets. Some even seem to like to inhabit the ramp. One morning when I checked the contraption to see if anyone needed help getting out, this spider was in no hurry to leave and crawled onto the underside, possibly hoping to catch easy prey. (Photo by Nancy Lawson)

Ramp up your skimmers. For those animals who do end up in the skimmer, a spiral-shaped ramp attached to the bottom of its cover offers safe passage to solid ground. Called the Critter Skimmer, this product is new in my pool but already appears to provide an easy exit for beetles, whom I find now hanging out on the top of the cover instead of swimming haplessly in the skimmer basket.

But animals must reach the skimmer before they even find the spiral ramp, and by then they may be poisoned by chlorine. Place a Frog Log upstream of the skimmer to allow frogs and others to exit that way first, and use the Critter Skimmer as a backup to help creatures who’ve bypassed it.

Image of butterfly outside swimming pool
Outside the pool, our patio garden draws swallowtail butterflies and many bees. Inside the pool fence, I’ve started converting the gardens to plants with fewer flowers or blooms that aren’t so enticing. (Photo by Nancy Lawson)

Fence and plant strategically. Enclose your pool with fencing to deter access. If your budget allows, consider screening in the entire pool—an expensive but effective way to let in air and sunshine while saving lives.

If possible, keep bees safe by locating plants that attract them outside the pool area. Inside our pool fence I’ve begun to cultivate native ferns. And though I normally replace daylilies with more wildlife-friendly plants, I’ve decided to leave them in this spot for now; they aren’t the invasive kind and, importantly for bees, lack the goodies that would entice pollinators too close to the water.

Image of Frog on frog log in swimming pool
Some animals like this green frog seem to like to hang out on the Frog Log, but we prefer to move them away from the pool because of concerns about chlorine exposure. A stream runs through the woods behind our house, but we plan to also add a pond to our habitat like the one below, where rocks and slopes provide steady footing for a chipmunk and other animals. (Photo above by Will Heinz; photo below by Kathy Milani)

Image of Chipmunk by pond

Give animals their own “swimming pool.” Provide animals with an alternative by installing a pond. Be sure to angle the sides into a sloping shape, and add well-placed rocks so everyone can climb out. Not only will animals feed and breed there, but your pond will also give you a place to relocate aquatic species you find in your pool.

Monitor constantly. Check pool skimmers at least twice a day, and closely observe activity around the pool. Never leave the area unattended for long periods; if animals get used to a human-free zone and start coming too close, tragedy can strike, as it did when one of our relatives left on a months-long trip and a fox family fell into his half-filled pool and died.

Protect amphibians and other wildlife in the broader environment by eliminating the use of fertilizers and pesticides and planting native species that will filter the groundwater.

Protect and restore wetlands. Help amphibians in other ways by reducing damage to their natural habitats, Mason advises. “Our stream networks are so impaired,” he says. “We’ve so upset the natural cycling of water, and the result of that has been severely degraded stream channels.” Floodplains no longer catch polluted waters for absorption and filtering, and muddy waters head downstream from eroded banks, resulting in poor environments for amphibians and many other creatures. Though Mason works on a broad scale to solve these issues, homeowners with smaller patches of land can do their part, too. Eliminate the use of fertilizers and pesticides to reduce nitrogen, phosphorus, and other pollutants. Plant rain gardens and other native plant gardens to direct runoff into the soil, where contaminants can be filtered.

Image of pickerel frog
This pickerel frog probably lived in the stream behind our house but came to visit one day, watching us from the sidewalk near the pool. (Photo by Nancy Lawson)

As his invention continues to help animals throughout the world, including in pools at a South African national park, Mason is developing other ideas for mitigating backyard hazards to wildlife. Still as amazed and overwhelmed by the diversity of life on the planet as he was in his younger days, he wants to continue to do his part to protect that life and hopes other scientists will start studying the swimming pool conundrum. In the meantime, he’s made it a lot easier for everyone else who cares about wildlife to be part of a simple and lifesaving solution.

This bumblebee found safety on a Frog Log—and then on my hand to dry off in the sun before flying away:

Learn more about mitigating  backyard hazards in my book, The Humane Gardener: Nurturing a Backyard Habitat for Wildlife.

*Featured image of tree frog by Nancy Lawson; pool gate photo by Cristina Bäckman