Houston Zoo Reaches One Million Egg Milestone in Houston Toad Recovery Effort

Collaboration brings medical imaging expertise to wildlife conservation

The Houston Zoo will release more than one million Houston toad eggs into protected habitat in Bastrop County by the end of April, one of the program’s most productive seasons on record. The releases are conducted in partnership with Texas Parks and Wildlife, the U.S. Fish and Wildlife Service, and the Association of Zoos and Aquariums colleagues at the Dallas Zoo and Fort Worth Zoo.

The Houston toad once ranged across more than a dozen Texas counties. Today, the species holds on in a narrow stretch of east-central Texas, with the largest remaining population in Bastrop County. The Houston Zoo has operated a dedicated breeding and head-start facility for the species for decades, producing egg strands each season that are released into protected wild habitat in partnership with state and federal wildlife agencies.

Counting and documenting that volume of eggs accurately is its own challenge. This year, the Zoo brought a new tool to the work: custom egg-counting software built in collaboration with Dr. Moiz Ahmad, a medical physicist in Houston. The software automates a process Zoo staff previously handled by hand, photo by photo, using paint software and a tally counter.

The collaboration started with a Zoo tour. Dr. Ahmad visited the herpetology team, learned about the egg counting challenge, and offered to help. Working with the Zoo team, he adapted imaging techniques from his work in diagnostic radiology to build a program tailored to the Zoo’s needs. The software processes photographs of egg strands through image shading correction, binarization, and segmentation to produce accurate counts at scale. In a test image containing approximately 8,000 eggs, the software returned a count of 7,900.

“This changes the scale at which we can work,” said Eddie Sunila, curator of Herpetology and Entomology at the Houston Zoo. “Dr. Ahmad took a problem our team had lived with for years and solved it. That kind of collaboration matters for what we’re trying to do for this species.”

The Houston Toad Recovery Program is part of the Houston Zoo’s mission to connect communities with animals to inspire action to save wildlife.