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.
Other recommendations include letting grass grow tall around such waters to protect them from chemical runoff and provide habitat for the adult amphibians as well as connect them to undisturbed native environments. "Seventy percent of golf courses are nonplay habitat," Semlitsch notes. "If you mix and mingle water features and adjacent natural areas you've got a good chance of playing a good game of golf and protecting those habitats."
But it may be tough to get golf course owners on board with the plan. The USGA-funded Audubon International has only enlisted some 600 courses since 1991. "The superintendents on golf courses seem very open to taking some of the management strategies into account," Boone says. "If the changes do not interfere with golfing and doesn't take substantial additional work, then why not do it?" After all, mowing requires more work than not mowing.
But some might argue that a dry pond with an unmowed fringe is unsightly, if a boon to wildlife. And, regardless, such human-dominated landscapes are not the equivalent of undisturbed nature. "It's not a substitute for natural areas or preserves," Semlitsch says. Such preserves may not be large enough and alternatives should be found, even if they are chemically challenged man-made ponds. "We could potentially do better than promoting the maintenance of one species, bullfrogs," Semlitsch notes, "to at least include a few other native species."