From Potter Park to Puerto Rico

For the past 5 years Potter Park Zoo has been participating in the Species Survival Program (SSP) for the Puerto Rican Crested Toad.  The Puerto Rican Crested Toad is listed as Threatened by the US Fish and Wildlife Service and is the only Native species of toad found in Puerto Rico.

Every year we undertake the difficult task of getting these toads to breed in captivity.  Prior to breeding we get recommendations from our SSP Coordinator regarding which toads are to be bred.  This ensures that all zoos participating in the program do their part and help to maintain genetic diversity in the breeding population.

Crested Toad EggsThe process by which we get the toads to breed is a very delicate task and our goal is to replicate the rainy season found in the spring and fall in Puerto Rico.  We begin by cooling the toads down to 66 degrees Fahrenheit and leaving them in this moist, cool environment for a month.  We check on them daily but they spend most of this time hibernating.  The cool temperatures are necessary for good egg development in our female toads.

After the cooling process, it’s time to wake them up!  We heat their room to 82 degrees Fahrenheit over the course of just three days and then spend a week feeding them and giving them anti-fungal baths to prevent the spread of Chytrid (a fungus that is very dangerous and responsible for killing off multitudes of amphibians world wide)  to the eggs and tadpoles.

Next we place the toads, split into their recommended pairings, into a specially made rain tank simulating natural conditions in the wild.  Due to difficulties in captive breeding we have to inject our toads with a hormone to assist with egg and sperm development.  During this time we play their breeding call until the toads amplex and eggs are laid.  Then we cross our fingers and wait.

This past round of breeding yielded up nearly 1200 tadpoles when all was said and done.  We shipped these tadpoles to Puerto Rico so that they could be released into the wild and help bolster the wild population.  Some years we hold a few back to raise to adulthood so that they can enter the captive breeding population and help maintain genetic diversity.

Though we have a protocol to follow, over the years, we’ve found that some very simple things make a large difference in the breeding of the Puerto Rican Crested Toad.  Water temperatures, adult toad diet, tadpole diet and method of cooling/heating have all needed to be tweaked to fit our zoo and our circumstances.  We are super excited to have been so successful this time around and we are looking forward to continued success!