Conservation Initiatives

Our conservation projects apply the tools and knowledge gained from scientific research to solve real-life problems threatening the world’s wildlife. These are actions where success is measured by their effectiveness in improving the security and stability of animal populations - both in the wild and in captivity. Though our scope is international, many of our initiatives are focused on U.S. species, including some here in the MidSouth. We work to conserve a broad variety of animals -- from small toads and spiders, to birds and snakes, to elephants and bears.

Dusky Gopher Frog Reintroduction

Animal: Dusky gopher frog, Lithobates sevosus

Project: Breed and release a sufficient number of dusky gopher frogs to be the genesis of a new population of this Endangered Species.

Why?: Without additional populations, the survival of the dusky gopher frog in the wild is unlikely. Using cutting edge reproductive technologies that were invented and refined by Memphis Zoo scientists, our research staff and our partners at the Detroit, Omaha, Dallas, St. Paul, and Birmingham zoos are preparing to produce thousands of froglets in 2018 and every year thereafter. The importance of succeeding couldn’t be any clearer – it could help save the dusky gopher frog from extinction.

A female dusky gopher frog next to one of its larval offspring.  The maturing tadpole has grown rear legs and is approximately three weeks from morphing into a miniature of its mother.

Memphis Zoo Research Fellow Beth Roberts and Dr. Ruth Marcec-Greaves, Director of the National Amphibian Conservation Center at the Detroit Zoo, are preparing to release a container full of zoo-bred dusky gopher frogs.

Adult dusky gopher frogs resemble toads, with squat bodies and “warty”-looking skin.

Dusky gopher frogs are released soon after they morph into frogs, which increases their ability to avoid predators compared to tadpoles.

Louisiana Pine Snake Reintroduction

Returning America’s Rarest Snake to the Wild:

Animal: Louisiana pine snake, Pituophis ruthveni

Project: Since 2010, we have been partnering with the U.S. Forest Service (Catahoula District, Louisiana) and our colleagues at the Audubon, Fort Worth, Ellen Trout, Phoenix, Jacksonville, and Knoxville zoos to release zoo-bred pine snakes onto restored habitat in Grant Parish, Louisiana to create a new, self-sustaining population of this critically endangered species.

Why?: Known from a mere 223 wild specimens since its discovery in 1927, the pine snake was extirpated from most of its historic range during the first half of the 20th century, due primarily to logging.  Today it persists on three tiny parcels of marginally suitable habitat in Louisiana, and these last populations continue a rapid decline.  Preserving these relict populations, alone, will not be sufficient to save the species. Since 2010, we have released 109 pine snakes back into the wild as of 2017, and many of our initial releases are now mature individuals so we expect to document reproduction soon.

A zoo-bred Louisiana pine snake peers from a pocket gopher burrow two years after its release into the wild. 

Louisiana pine snakes spend 90% of their lives underground.  This snake was found because it was implanted with a small radio transmitter enabling researchers to observe its movements and behaviors. 

The somber coloration and rough-hewn aspect of a wild Louisiana pine snake reflect the harsh, dry environment in which it lives.

Steve Reichling searches for a signal from the transmitter implanted in a pine snake.  The snakes can be detect and located when they are up to a mile away from the researcher. Photo by Dino Ferri.

A zoo-bred hatchling pine snake is released into a stump hole in the Louisiana piney woods. Photo by Emlyn Smith, U.S. Forest Service.

Partners from the U.S. Fish and Wildlife Service, U.S. Forest Service, Louisiana Dept. of Wildlife and Fisheries, Ellen Trout Zoo, Fort Worth Zoo, and Memphis Zoo at the release site for zoo-bred Louisiana pine snakes.  Photo by Gordon Henley.

A hatchling pine snake carrying a radio transmitter rests for a few moments after being released, while biologists work in the background.

The health of released pine snakes is monitored by several means.  Here, a blood sample is being taken by a zoo veterinarian.

Freezing Sperm and Preserving Biodiversity

  • Animals: Amphibians – Dusky Gopher Frogs (Lithobates sevosus), Houston Toad (Anaxyrus houstonensis), Wyoming Toad (Anaxyrus baxteri
    Reptiles – Louisiana Pine Snake (Pituophis ruthveni), Eastern Indigo Snake (Drymarchon couperi)
  • Project: The Memphis Zoo research team works on a number of research projects that focus on freezing (cryopreserving!) sperm from frogs, toads, and snakes. Through these projects, we have partnered with the U.S. Fish and Wildlife Services, Houston Zoo, Omaha's Henry Doorly Zoo and Aquarium, Leadville National Fish Hatchery, Central Florida Zoo, and Orianne Indigo Conservation Center to develop ways to increase the success of freezing sperm.
  • Why?: Freezing sperm from these threatened and endangered animals will help us preserve the genetic material from important individuals that can be used to fertilize eggs long after the individuals themselves are gone. More immediately, developing good freezing techniques will allow us to breed individuals from other Zoos or wild populations with those within Memphis Zoo. By having frozen sperm, we can simply ship the samples, without having to move the animals all across the country or even across the globe!

Kristin Hinkson (Research Technician) examining developing toad eggs under the microscope.

Houston toad sperm

Dr. Sinlan Poo (Postdoctoral Researcher) freezing Wyoming toad sperm using cryopreservation techniques.

 Developing Houston toad eggs (early developmental stage)

Developing Houston toad eggs (late developmental stage)

Lab work looking at quality of toad sperm.

Studying the Giant Panda

Giant Panda Ecology

  • Animal: Giant Panda (Ailuropoda melanoleuca)
  • Project: Since the arrival of the giant pandas, Ya Ya and Le Le, in 2003, the Memphis Zoo has worked with national and international partners to understand the many facets of giant panda ecology. Memphis zoo researchers, graduate students, keeper staff, interns, and volunteers have contributed directly to increasing the international community’s knowledge of the behavioral, nutritional, reproductive, and chemical communication ecology of captive and wild giant pandas.  
  • Why?:  40 years ago, both the captive and wild populations of giant pandas were at risk of extinction. Concerted international efforts to develop assisted reproductive techniques and to understand the nutritional needs of giant pandas, has led to a global boom in captive bred cubs; however, persistent reproductive failure for many females still occurs. Therefore, research needs remain such as the need for the development for reliable pregnancy detection and understanding reasons for pregnancy loss. As China rapidly increases its protected forest land, efforts towards reintroduction of captive born animals are also increasing. Our collaborative research into giant panda nutritional and behavioral ecology, chemical communication, and forest health studies adds to the knowledge to draw from as scientists in China work to prepare cubs and improve reintroduction success of the giant panda.

Researchers at the Memphis Zoo are studying why, when, and how pandas eat bamboo.

Research scientist, Beth Roberts studies giant panda reproduction and teaches research intern, Lina Rodriguez, how to measure hormone levels in panda urine.

Giant panda, Le Le, scent marking during the breeding season. Memphis Zoo researchers study the chemical communication of giant pandas.

Assisted Reproduction

Saving Species Using Assisted Reproductive Techniques 

  • Animals: mammals, amphibians, and reptiles
  • Project: The Memphis Zoo research team uses various assisted breeding techniques to conserve captive populations and improve breeding success. The team works to increase captive populations of many endangered animals including giant pandas, polar bears, African elephants, snow leopards, amphibians, and reptiles.  Working closely with our zoo veterinarians, keepers, and management team, the Memphis Zoo research team partners with other zoos, universities, U.S. Fish and Wildlife Service, and other institutions to apply these state-of-the-art techniques.
  • Why?: Animals at the Memphis Zoo are part of the larger U.S. zoo population and reproduction is an important part of successfully maintaining captive populations. Because animals are spread throughout the country, zoos work together to ensure breeding success to maintain population numbers and genetic diversity. Assisted reproduction consists of a wide variety of techniques that can include hormone monitoring, semen collections, sperm cryopreservation, artificial insemination (AI), in-vitro fertilization, and pregnancy monitoring. The employment of multiple techniques can be necessary in the reproduction of some species such as giant pandas. These techniques can also be used to optimize the timing of breeding introductions and AI procedures. 

Changes in the amount of hormones in urine and fecal samples give researches insights into the reproductive physiology of animals at the zoo.  From our research work, we were able to use urine samples collected off the floor to determine that Ateri, a female snow leopard, was pregnant in 2013.

Researchers at the Zoo use assisted reproductive therapies to collect amphibian sperm and eggs and perform in-vitro fertilization. For some species, researcher also use these techniques to produce frogs and toads for reintroduction into the wild.  

Collection of toad eggs for in-vitro fertilization.

Beth Roberts assesses sperm quality and movement under a microscope after collection. Fast movement in a straight line is important measure of sample quality for many mammals and reptiles. In comparison to mammals, many amphibians normally have slow sperm.