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Other Success Stories
There are currently no plans to release the zoo’s Togo slippery
frogs into the wild. However, release is the goal for some species,
including Puerto Rican crested toads and Blanding’s turtles.
The number of endangered Puerto Rican crested toads has
plummeted from habitat loss and the arrival of invasive species.
CZS is among the institutions producing tadpoles for release
in Puerto Rico to restore the population. Brookfield Zoo has a
colony of 26 toads. Since 2016, the zoo has sent 12,323 tadpoles
to Puerto Rico.
Closer to home, Snider and his team are making an impact
on a species native to the area —Blanding’s turtles. The turtles are
5 to 7 inches long and can be recognized by a bright yellow chin
and throat. They live in wetland habitats throughout the Midwest,
in parts of the eastern U.S., and Canada. They are long lived—
To determine what to feed the Togo slippery frog tadpoles, they living as long as 80 years. They are endangered because of habitat
noted that the tadpoles of many similar species are algae-eaters. loss, illegal poaching for the pet trade, and increased predation.
Not surprisingly then, some of the slippery frog tadpoles were feeding For the past 10 years, Brookfield Zoo has participated in the
on the naturally growing algae in their tanks. Using trial and error, Blanding’s Turtle Recovery Program. Hatchlings are brought to
they experimented with fish flakes and algae pellets and found the the zoo in the spring by the Forest Preserve District of DuPage
tadpoles that consumed this more nutritious diet grew up faster. County and head-started in the zoo’s Dragonfly Marsh. They are
The frogs’ natural habitat in Togo is characterized by fast- then picked up in the fall and released into the forest preserves by
moving streams and water falls. The Herps team simulated this DuPage forest preserves staff.
habitat in tanks they set up in the basement of THE SWAMP. Approximately 25 of the turtles currently live in the zoo’s
Some of their groundbreaking discoveries about the husbandry breeding pond and many are just reaching adult size and age.
and breeding of the species include: It has taken 10 to 15 years for the turtles to reach sexual maturity
and begin to breed, which just occurred in 2019.
• Female frogs lay clutches of 100 or so eggs at a time. “This is a very time consuming and intensive project,” said
In seven to nine days, the eggs hatch into tadpoles. Snider. In the spring, all the adult turtles must be caught to
• At birth, tadpoles are white. They change color as they grow. be weighed and measured. The turtles are regularly monitored
• Tadpoles metamorphize into young frogs in about for gravid or pregnant females. “You have to be there when the
six months. females start to reproduce,” said Snider. “Every egg laid must be
• The frogs reach breeding age at 1 to 2 years old. weighed, measured, and incubated—we had more than 70 eggs
• The male frog hangs out over a clutch of eggs and appears last year.” Once the eggs hatch, the hatchlings must be weighed
to urinate over them. This is thought to reduce the pH in and measured and cared for all winter.
the surrounding water, which prevents mold and fungus So far, CZS has released 12 of the zoo’s captive-produced
from growing on the eggs. turtles from the first breeding year into the DuPage forest
• The theory that Togo slippery frogs do not use calls to preserves. Jeff Bocek, a senior animal care specialist with Herps
& Aquatics, volunteered to lead the Blanding’s turtle effort.
communicate or in mating is false. “We were hearing loud, “I have a wonderful group of people,” said Snider. His team
high-pitched calls from our basement,” said Snider. of eight includes two lead animal care specialists, five senior
• A “sucker-disk” on the tadpole’s belly provides traction animal care specialists, and one animal care specialist. “They are
when they are in fast-flowing water. excited and want to learn and do the best they can for the
Brookfield Zoo currently houses approximately 100 Togo animals,” he said. “Without the right staff, the success we’ve
slippery frogs of various sizes and ages. Just recently, F2 progeny had would not have been possible.” █
(i.e. the captive-produced young from captive-produced animals)
were produced for the first time. The husbandry and breeding
techniques developed at CZS may be used to set up a conservation
breeding facility for Togo slippery frogs in Ghana.

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