"We're hoping to show the Haitians that these frogs have value," Hedges said. Over several expeditions, he and Carlos Martinez, a zoo conservation biologist, have brought 154 live frogs from Haiti. Their number at the zoo has climbed to an estimated 1,400. Of 10 original species, nine have produced young.
Reptile keeper Joyce Foreman works with Martinez to figure out what to feed the frogs and their tiny offspring. In an adjoining room, Parker shows the various insects she's raising in plastic containers.
The zoo has tried fruit flies, she said, but the frogs tend to ignore them. Other menu options are live pill bugs, crickets, bean beetles, and springtails.
Parker and Martinez have experimented with temperature and humidity, hoping to re-create the conditions of the cool mountain forests where the frogs were caught. "We don't know the exact ecology," Martinez said. "We're learning along the way."
The most prolific species are the La Hotte frog, the breast-spot frog, and a tuneful frog named after Wolfgang Amadeus Mozart.
Another musical species, the La Hotte glanded frog, has a metallic chime to its call, Parker said, but this creature is more difficult to breed. The offspring are tiny and so far haven't survived in captivity.
The frogs are not currently on display, though some hardier species may become part of an exhibit.
While North American frogs go through a tadpole stage, many tropical species either give live birth to tiny frogs or lay eggs that hatch into froglets, Martinez said.
Some of the Haitian frogs are so small the adults can fit on a quarter. Some are greenish, some reddish, some spotted, some pudgy, and some leggy.
Haitian officials asked about the living conditions and the frogs' safety. Lyonel Valburn, the director general of the Haitian Ministry of Agriculture, said he was pleased he could count on Philadelphia to take care of Haiti's frogs.
The zoo is no substitute for the rich forests that once made Haiti a paradise. The nation is home to 50 known species of frog, though Hedges has found enough new ones to suspect Haiti is losing frogs that will never be known to humanity. On an evening trek, he once discovered five new species.
Though Haiti has set aside national parks, the government hasn't been able to enforce the boundaries, Hedges said. People still come in and cut down trees to make charcoal, which they depend on for cooking.
After the morning tour, Hedges and Martinez spent the afternoon with the Haitian officials, trying to work out some plan to preserve Haiti's tiny but diverse patches of forest. Along with the agriculture official were two people from the division of parks and soils, and leaders of the Haiti Audubon Society.
The participants discussed many possibilities, including educational programs, building "ecolodges" for tourism and research, farming trees for charcoal, and paying people not to destroy the forest.
Some scientists view Haiti as a microcosm of the world and an example of what can happen when human beings put extreme stress on the environment.
Hedges said he and other biologists were not balancing the lives of humans against those of frogs. If people remain dependent on cutting trees, then when the last forests collapse, they will die too.
Contact Faye Flam at 215-854-4977, email@example.com, or follow on Twitter @fayeflam. Read her blog at philly.com/evolution.