Saving a Critically Endangered Toad Species 7,300 Eggs at a Time

Written by Colin Thompson


While the Houston toad hasn’t been seen in the wild in Houston since 1973, the Houston Zoo currently houses about 400 of them. Every year, we use this captive assurance population to bolster the wild population in Bastrop County. In 2015 we released about 600,000 eggs and in 2016 we released over 775,000 eggs. During the 2017 breeding season, we hope to release even more! Moving those eggs from Houston to Bastrop is no simple task though. This year, we’re taking a closer look at the impact our transport practices could be having on the viability of the eggs after they’re released.

Houston toad eggs are very fragile, as they lack a hard or leathery shell like bird or reptile eggs. Instead, the eggs are suspended in a jelly which forms a long strand. Each female toad lays one egg strand per year, and each strand contains an average of 7,300 eggs, with larger strands reaching over 14,000! To make sure we are using the best possible methods to transport these large masses of eggs, we’re setting aside about 100 eggs from each egg strand to monitor as a “control group”. The “control” eggs stay at the Houston Zoo, while the rest of the strands are driven two and a half hours away to Bastrop County. When we arrive, we remove another 100 eggs from each strand before releasing the majority of the eggs into the wild. We then drive those 100 eggs back to Houston to observe alongside the control group. By doing this, we can see if the development of our eggs is being hindered by the journey to Bastrop County, allowing us to alter our methods for better viability.

So far, we’re finding that the transported eggs are developing at the same rate as the control eggs, which means our transportation methods are not having a negative impact. This is great news for Houston toads! Keep checking back for updates on this year’s Houston toad breeding project, and be sure to visit the Swap Shop and Reptile House to see this awesome native species in person!



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Houston Zoo added 9 new photos to the album: Double Dose - Second Baby Giraffe in Two Weeks!
Houston Zoo

We've got a second baby giraffe! Monday morning brought the welcome arrival of a second baby giraffe in two weeks for the Houston Zoo herd. The female Masai giraffe was born at 8:30 a.m. on Monday, April 24 to second-time mom, Asali. Read more here: www.houstonzoo.org/blog/second-giraffe-born-two-weeks/ ... See MoreSee Less

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Weve got a second baby giraffe! Monday morning brought the welcome arrival of a second baby giraffe in two weeks for the Houston Zoo herd. The female Masai giraffe was born at 8:30 a.m. on Monday, April 24 to second-time mom, Asali. Read more here: http://www.houstonzoo.org/blog/second-giraffe-born-two-weeks/

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I really need to go to the zoo soon!! Lacey Jones - 2 new babies - we have to go!! Kendyl would love it!!! Lol. Dorothy Reuter - your granddaughter needs a trip to the zoo!!

I was wondering the 2 baby giraffes did they come from the same mother giraffe and she had twins but different day and time or there is 2 different mother giraffes had separate baby giraffes ?

Breonna Canova, let's make the guys take us to the zoo! They have 2 baby giraffes!!!

Karen Winkler, we're dropping giraffes left and right here in Houston. 😂

Lori Beam another giraffe had a baby Monday at the zoo!

Kimberly Hegefeld take Lila to the zoo and I'll take along with y'all. Lol. Look how cute they are.

Lauren Kurtz now we really need to go to the zoo. They have 2 now😊

Raquel Sosa 😭 omg i just cant take the cuteness f u april 😂

Tonya, I think we might need to plan another trip! 😄

Emily Maldonado zoo trip round two?? This time maybe even McKenzie Sandefur CAN FREAKIN GO UGH. HOE MOVE.

Love it! So adorable!!!! Giraffes gone wild...so many babies this spring! Congrats!🎉

We have to go to the zoo when your dad and I are there. Can I play with the 2 babies ?

Congratulations!! She looks healthy and beautiful: a testament to great care of the parents!

Jeanette Ellison I bet you are one happy Giraffe lover lol

Well Jonathan, you gotta take me back. They have TWO baby giraffes. 😍

Lisa Pfaffinger come back so we can see both baby giraffes!!

Zindzhi is my favorite because she was born on my birthday! Can't wait to see them!!

Kristen Hicks Gardner , we need to take a trip with the kids soon.

Abundance of joy! Congratulations Houston Zoo and Mama Giraffes. ❤️

I'm going to have to make a trip to the zoo soon. I ❤ the giraffes!

Raina Johnson Bell Ashley Andrews Jessica L Kemp Okay. This is a sign. Bring your asses to Houston so we can go SEE THESE BABIES!!!!!!!!!!!

Ashley Chaney look she was born on your birthday! 😍😍😍

Kristine Ramos, another one!!! My heart can't take the cuteness

Sheri Lord Spagnolo, I believe a girls trip to Houston might be needed.

Luis Antonio Barrientos take me this weekend to go see the baby Giraffes

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