Golf courses are among the most manufactured of all landscapes: manicured greens, rigorously mowed fairways and chemical-laced ponds. "In essence, golf course managers are one-crop farmers; they grow grass," says Kevin Fletcher, executive director of Audubon International, a group dedicated to promoting golf courses as nature reserves (and no relation to the bird-, though not necessarily birdie-loving National Audubon Society).
Such an obsessive focus on grass, not to mention on knocking tiny white balls into little cups in the midst of verdant scenery, might not seem like the ideal setting for animal life. But new research, funded by the United States Golf Association (USGA), shows that water hazards, the bane of many a duffer's handicap, may provide a refuge for native amphibians, raising hopes that these human-dominated landscapes can provide them another habitat.
"We went into this thinking that golf courses were going to be pretty nasty places," admits biologist and occasional golfer Ray Semlitsch of the University of Missouri–Columbia. "We started out with the idea that we'd be studying the effects of chemical contamination. Golf courses, from our perspective, seemed to be a place where there were a lot of chemicals used."
But those very chemicals may have actually helped the three amphibians studied: American toads, southern leopard frogs and spotted salamanders. Researchers placed 10 boxes containing quantities of amphibian young in four ponds—two on golf courses and two in chemical-free U.S. Geological Survey ponds.
To their surprise, the amphibians reared in the golf course ponds did better than those in the protected ponds. "One hypothesis is that contaminants used at the golf course sites could be negatively impacting invertebrate populations," but not the amphibians, says biologist and study co-author Michelle Boone of Miami University in Oxford, Ohio. "Insects are more sensitive to insecticides than are most vertebrate species."
A chemical test conducted at the end of the summer experiment found no traces of contamination but they could have been present early in the season, Semlitsch argues. With fewer dragonfly and beetle larvae about, more of the three amphibians could survive to maturity as these insects are "voracious predators," he says.
The amphibians in the golf course ponds also only thrived there if no bullfrog tadpoles were present. These typically larger amphibian offspring dominate man-made ponds throughout North America, gobbling up all available food, including their smaller peers, biologists say.
It remains unclear, however, whether the three amphibian species could complete their life cycles on the course. One of the test courses "would have to be changed radically to maintain those species," Semlitsch says, but the other has "a fair amount of natural habitat, including oak-hickory forest and native grasses. I think it could maintain a small population, perhaps. I don't know how healthy they might be."
Boone adds: "Amphibians associated with grasslands, for instance, may be more likely to be able to complete the life cycle on golf courses than forest-associated species, because there is more potential to maintain unmowed grassland areas than thick forests."
Given the proliferation of golf courses—there are more than 17,000 in the U.S. alone—combined with recent legal decisions limiting protection of wetlands, they may become some of the last such refuges. The key will be mimicking nature. "What we've done," Semlitsch says, "is create something that is totally artificial," ponds that never dry. By drying the ponds long enough to kill bullfrog tadpoles—a few days in late summer to match natural cycles—golf course managers could promote a broad range of biodiversity as amphibians and other species thrive in such temporary wetlands. This recommendation could work throughout the continental U.S., and even in Europe.