Tuesday, December 10, 2013

Buffalo Zoo Ships Tadpoles As Part of a Major Wildlife Conservation Effort

by Katrina McIntosh, reptile keeper at the Buffalo Zoo

The Buffalo Zoo shipped out over 1400 Puerto Rican crested toad tadpoles on November 19 2013 to be released back into the wild in Puerto Rico!

The Puerto Rican crested toad is an amazing amphibian! Within 24 hours after eggs are laid, tadpoles hatch and cling to their egg strands.  At this point they look like swirly blobs. After another 12- 24 hours pass, they become free-swimming tadpoles. They develop back legs within 10 days. Front legs appear a few days later. Shortly after developing these front legs, they will emerge from the water and live on land. The tadpoles still have a little of their tails left when they start living on land. They will absorb the remainder of these tails within a day or two. Once they no longer have tails they will start to eat smaller versions of what the adult toads eat. This whole process takes about 21 days which is incredibly fast for an amphibian!

An emerging Puerto Rican Crested Toad tadpole.
Since these tadpoles grow so quickly, every day they look bigger and have new changes. As an animal keeper at the Zoo, it is exciting to see the changes and watch them grow into toads. The Buffalo Zoo usually ships tadpoles around a week after they hatch, so that they are still small enough to ship safely. We participate in a Species Survival Plan (SSP) for this species.

An adult Puerto Rican crested toad.

All of the tadpoles we released this year were from one set of parents. The female is about 7 years old and the male is 2 years old.  A lot of preparation is made for breeding these toads. First, the toads go through a cooling cycle. This is where they are placed in an area where they are cooled to 66°F for about a month.  This encourages the female to produce eggs. Once they are done being cooled, they are then fed for a week straight. After they have had a week at their normal temperatures of 86°F they are then placed in a large tub that is half-full of water. This tub is set up 2 months prior to the breeding to grow green algae which the tadpoles will eat. There are fake plants, ceramic pots, and floating hide huts in these tubs to give the toads access to land areas and lots of items for the female to lay her eggs around. We even set up a sprinkler to act as rain in the tub. The toads tend to breed during rain events in Puerto Rico, so the rain bar mimics rain. While the female lays her eggs, the male rides around on her back fertilizing them through external fertilization. Once all eggs are laid, the toads are removed from the tub and placed into tanks where they will be feed daily for a week and monitored closely. The parents are removed so as not to disturb the delicate eggs. Within 24 hours of the eggs being laid tadpoles will hatch.

Katrina McIntosh packs tadpoles before shipping to Puerto Rico.
Puerto Rican crested toads were nearly extinct by 1980 due to habitat destruction and predation. As a result of conservation efforts and programs by zoos, there are now some stable populations of these toads in the wild. It is very rewarding to work with this program and to know that the Buffalo Zoo is doing our part to help save the Puerto Rican crested toads.

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