Rainforest frogs flourish with artificial homes

Build pig puddles in the rainforest and they will come. When scientists created wallows mimicking those left by wild peccaries, a local population of rainforest frogs that mature in puddles grew by about 50 percent, the researchers report in the Jan. 29 Behavioral Ecology.

For conservationists, this population boom indicates that “you have to protect a whole ecosystem and not try to focus on a single threatened species,” says Eva Ringler, a behavioral biologist at the University of Vienna and coauthor of the study.

Ringler and her team monitored a population of brilliant-thighed poison frogs (Allobates femoralis) in French Guiana. The frogs lay eggs in leaf litter. When the eggs hatch, the father carries the tadpoles piggyback-style to pools of standing water. Rain-filled puddles left by peccaries — hairy, piglike mammals that trample and roll on the forest floor — are ideal.

The frogs that Ringler’s team studied lived in an area with fewer peccaries than other regions, so the researchers added fake wallows by digging holes and filling them with buckets of water. Within two years, the number of frogs captured in the study area grew from 231 to 352. It’s likely that the big, convenient pools helped more tadpoles survive, says Ringler.

While brilliant-thighed poison frogs aren’t endangered, many species of frogs worldwide are threatened by habitat loss and pollution. The success of the pig puddles indicates that humans may be able to help struggling amphibians by manipulating their surroundings, Ringler suggests.