Innovative Husbandry Uncovers Keys to Sustainability

August 2016

By Mary Ellen Collins

Help wanted:  Seeking animal advocates who possess an investigative nature, ingenuity, persistence and patience. Experience solving puzzles preferred.

The husbandry pros who fulfill those requirements tackle challenges to population sustainability on a daily basis, making significant contributions to the future of endangered species.

“It starts with researching and understanding what happens in the real world and trying to recreate that,” said Colleen Lynch, curator of birds at Riverbanks Zoo and Garden in Columbia, S.C., and  consulting population biologist for the Association of Zoos and Aquariums’ (AZA) Population Management Center at the Lincoln Park Zoo in Chicago, Ill. “We’re always striving to make things better and that is an ever-evolving process that starts with our knowledge of the animals and ends with our creativity.”

Reviewing past data and collecting new information is the basis for what can be a long process of addressing health and breeding challenges. For example, Sean Foley a herpetologist at the Riverbanks Zoo and Garden and the Species Survival Plan® (SSP) coordinator for five leaf-tailed gecko species, has spent years determining best practices for maximizing the animals’ juvenile survivorship by pooling information from researchers in Madagascar and other SSP coordinators with a helpful website ( He knows that the path to receiving the 2005 Edward H. Bean Award for long-term propagation and captive husbandry of the leaf-tailed geckos was neither short nor direct.

“In the early years, we tweaked enclosures, lighting, heat and humidity,” he said. “Leaf-tailed geckos are susceptible to bacterial infections and females have reproductive challenges. If we’re not getting eggs, I might change the temperature, separate the males from the females or change up the groupings. It’s a lot of trial and error…and there’s always room for improvement. As soon as you think you have everything perfect, something else will happen.”

The strategies that curators use to encourage breeding are as varied as the animals for which they provide care; despite all obstacles, an overall sense of optimism prevails.

In the Air     

“One of the main challenges with birds is that they are so diverse,” said Diane Olsen the assistant curator at Moody Gardens Rainforest and Aquarium in Galveston, Texas, and Pelecaniformes Taxon Advisory Group (TAG) chair and Avian Scientific Advisory Group (SAG) chair. “What works for one doesn’t work for another, and there is still a lot of guesswork.”  For some species, simply managing demographics has led to breeding successes.


“Originally, we managed and bred the blue-gray tanager and the red-capped cardinal in pairs,” said Tim Snyder, curator of birds at the Chicago Zoological Society – Brookfield Zoo in Brookfield, Ill., and Passeriformes, Coliiformes, Capimulgiformes and Trogoniformes TAG chair. “It can sometimes take a while to find a suitable breeding pair, and we might miss as many as two breeding seasons waiting. We now have multiple institutions holding single sex flocks from which we can easily find a match.”

The blue-gray tanager population has increased by more than 50 percent, and even though the red-capped cardinal has struggles with survivorship, Snyder expects that once that issue is addressed, the cardinal will follow the tanager model.

In 2003, the tawny frogmouth population was aging and heavily skewed toward males, according to Mark Myers, the curator of birds at Woodland Park Zoo in Seattle, Wash., and Tawny Frogmouth SSP coordinator. He began to import birds from Europe and Australia and sent them to institutions that had proven success in breeding them.

“Frogmouths have always been popular as ambassador animals, and there was a big demand for them within that community. But if we wanted the population to be here in 20 to 30 years, we had to focus on breeding.”

Myers reports that SeaWorld Orlando in Orlando, Fla., was one of the first institutions to make frogmouth breeding a priority and has since become a helpful resource for other institutions that joined that effort. “We’ve really turned the corner, and we now have a good base of young animals that can breed.”

With other birds, adjusting the physical environment holds the key. “The sub-Antarctic penguins live where the light [goes from] bright light for 18 hours a day and no real dark to barely any light for a few hours a day, and that change tells their bodies when to breed and when to molt,” said Olsen. “By re-creating these extremes, we are providing the most natural light cycle we can. We also added new UV lighting because research tells us that they use UV reflectance off of their feathers as a sign of health and fitness. We are already seeing courtship behavior we wouldn’t normally see at this time of year, and we are really looking forward to seeing what happens during breeding season.”

On the Ground  

White Rhino © Thinkstock

For the white rhinoceros, being paired off is not the path to breeding and animals are more successful when managed in herds, according to Adam Eyres the hoofstock curator at Fossil Rim Wildlife Center in Glen Rose, Texas, and White Rhino SSP coordinator. “When we started bringing white rhinos over in the 1960s and 1970s, we brought them in pairs and lost a number of generations because they didn’t breed. San Diego was one of the first zoos to put them out in a herd with one boy and many girls, and they did breed. The eight zoos that are managing in larger groups are having success, but space restrictions are an ongoing problem.”

Sometimes sustainability requires a shift in perspective among zookeepers, as it did with efforts related to the southern tamandua.

“They are such stellar ambassadors, they are often taken out to classrooms,” said Harrison Edell the senior director of living collections at the Dallas Zoo in Dallas, Texas and the Ciconiiformes and Phoenicopteriformes TAG chair and Southern Tamandua SSP coordinator. When two thirds of the population were comprised of solo animals for educational outreach, with only one third having the opportunity to breed, Edell encouraged colleagues to change their approach.

“If outreach managers wanted access to ambassador animals, we made it clear that we would give priority to zoos that would make room for two and breed them. It was a huge paradigm shift to get [outreach staff] to think differently about the animals in their programs.” Since approximately a dozen zoos have implemented this plan, population analyses have demonstrated a significant increase in the SSP’s  population sustainability.  

The team at Central Florida Zoo’s Orianne Center for Indigo Conservation in Sanford, Fla., is experimenting with new housing as a way to encourage breeding of the eastern indigo snake, according to Michelle Hoffman, snake specialist and Eastern Indigo Snake SSP coordinator.

“The indigo snake is unusual because it is always moving and foraging and it needs a lot of room. A lot of zoos and breeders keep them in rack systems, which is not ideal because of the artificial light and air. We’ve created 28 outdoor enclosures that are 6 ft. x 9 ft., each of which houses one snake. When breeding season starts, we will introduce a mate selection process with the males, and depending on the results, we will introduce a female. It’s too soon to tell how successful this will be, but we’ll be watching.”

Under the Sea

Understanding the breeding habits of fish is definitely a work in progress, according to Beth Firchau, director of husbandry at the Audubon Aquarium of the Americas in New Orleans, La., and Marine Fishes TAG chair and vice chair of AZA’s Aquarium Affairs Committee. “There are thousands of species of fishes…and it’s just recently that we can track fish long-term through their life cycle. We’re still cracking the nut on what fishes need in order to reproduce.”

Factors affecting the managed breeding of the sawfish include the small number of species within AZA-accredited facilities, the fact that many of the animals are not paired and many are too young to breed. The one reproductive success in this species took place at the Atlantis Paradise Island Aquarium in the Bahamas.

“They’re in natural sea water and exposed to natural sunlight there,” said Stacia White, senior aquarist at Ripley’s Aquarium in Myrtle Beach, S.C., and Sawfish SSP coordinator. That location makes it easier, but it’s logistically impossible in other places.”

Sawfish © thinkstock

Initial efforts to promote breeding include shifting animals among facilities to create more male/female pairs and adjusting the water temperature. The Dallas World Aquarium in Dallas, Texas, houses its sawfish in an aquarium within a larger greenhouse/aviary exhibit, said director of husbandry Paula Carlson, who also serves as Marine Fishes TAG vice chair and International Union for Conservation of Nature (IUCN) Sawfish Specialist Group member. “They receive natural lighting through the greenhouse canopy, and the temperature of the exhibit fluctuates seasonally. I believe both of these factors are important to promote breeding, and we’ve seen some very encouraging behavior with our sawfish trio.”

Temperature adjustments may also be the answer for the sand tiger shark. “To my knowledge, no AZA institution has had successful breeding of the sand tiger shark,” said Chris Schreiber, director of operations, fish and invertebrates at the Georgia Aquarium in Atlanta, Ga., and Sand Tiger Shark SSP coordinator. We have learned that sand tiger sharks are migratory…so we have started to track the movement of certain groups and found that they can tolerate temperature swings. When the water starts to warm up, they’re inclined to seek others’ company.” 

By fluctuating the temperature anywhere from 2 to 20 degrees Fahrenheit, Schreiber and colleagues at other facilities have seen the sharks’ successful act of copulation, but they don’t know if fertilization has taken place. And in addition to tracking natural insemination, Schreiber’s team is also experimenting with artificial insemination with the sharks. As their experimentation continues, Schreiber said, “Facilitating communication among all stakeholders shortens our learning curve. If everyone maintains an open mind and open lines of communication, everyone stands to benefit. Success will be a little sand tiger.”

The husbandry professionals’ commitment to creating optimal management programs for the animals in their care is inextricably linked to sustainability efforts. “If we don’t learn how to effectively breed and manage animals, we won’t have a future and they might not have a future,” said Lynch. “We can’t meet any other goals without excellent husbandry.”

Mary Ellen Collins is a writer based in St Petersburg, Fla.






