The past three weeks in the Houston toad facility have been a whirlwind of activity. Keepers, veterinary staff, and toads have all been racing the clock to get everything prepared to try to squeeze in a breeding event before the end of Houston toad’s normal breeding season. We are happy to announce that in all we were able to produce ~36,000 Houston toad eggs that have now been released in and around Bastrop State Park.
This marks the first release of eggs from the Houston toad facility. Generally, the survivorship of eggs in the wild is quite low, around 0.01%! However, our collaborators at Texas State University placed the egg strands inside wire cages, termed “predator excluder devices,” to protect the eggs from getting eaten by birds, fish, aquatic invertebrates, and even other amphibians! The eggs will develop and hatch inside the protective wall of these cages. Eventually, the resulting larvae and tadpoles will swim through the wire mesh; however, the cage will be left in the water so the tadpoles can continue to use it as a hiding place.
A graduate researcher from Texas State University is currently monitoring the developing eggs. She has recently observed very large Houston tadpoles hanging around one of the excluder devices from the first batch of eggs released, indicating that they are working and the tadpoles are surviving!
We kept a few of the eggs in the Houston Zoo’s toad facility to grow up to “toadhood” so they can be a part of our captive assurance colony. These little toads are the offspring of some of our oldest and most “genetically precious” toads that we have here in the facility. Two of the females and three of the males that laid eggs last week are members of the very first group of toads that were brought into the toad program in 2007. We’re so happy that these toads are getting their offspring back into the wild!
Fingers crosses that the egg strands will produce lots of little toadlets that will be chorusing at the Bastrop ponds next year!