Chicago Zoo Raises 12,000 Tadpoles for Rarest Toad

Thousands of tiny tadpoles are hopping toward survival thanks to an ambitious conservation project at Brookfield Zoo Chicago.

The zoo recently raised and released 12,244 Puerto Rican crested toad tadpoles in its largest single breeding effort yet. This marks a major milestone for one of Earth's rarest amphibians, a species once thought completely extinct in the wild.

Over the past decade, the zoo has contributed nearly 40,000 tadpoles to help restore this critically endangered toad. Each tadpole represents months of careful work that happens mostly behind the scenes.

"From carefully coordinating breeding pairs to hand-counting thousands of tadpoles and tracking toads in the field, every step plays an important role in helping restore this species," said Mike Masellis, the zoo's lead animal care specialist.

Saving a species requires perfect timing. Zoo staff must coordinate breeding efforts with Puerto Rico's rainy season, when wetlands temporarily fill and give tadpoles the best chance at survival.

Once the tadpoles hatch, staff count and monitor each one before transporting them to Puerto Rico. There, conservation teams release them into managed aquatic habitats and watch as they transform into adult toads.

Last fall, zoo staff even traveled to Puerto Rico to monitor reintroduced toads in the wild. They studied predator threats, habitat quality, and environmental conditions to learn what helps the species thrive.

The Ripple Effect

Protecting this tiny toad does more than save a single species. Amphibians are incredibly sensitive to environmental changes, making them valuable indicators of ecosystem health.

When conservation teams protect habitat for the Puerto Rican crested toad, they also preserve wetland ecosystems that countless other species depend on. Today, the last wild population survives only in southwestern Puerto Rico's Guánica Commonwealth Forest.

The toad recently got an unexpected boost from an unlikely source. Puerto Rican superstar Bad Bunny featured the amphibian in his Grammy Award-winning album, introducing millions of fans worldwide to their country's only native toad.

Brookfield Zoo now lets visitors see two Puerto Rican crested toads on public display, giving people a rare chance to connect with an animal usually kept behind closed doors for conservation work.

"Our hope is that years from now, some of these tadpoles will return to the breeding ponds as adults and continue establishing future generations in the wild," said Masellis.