Turtle & Tortoise

Aldabra Giant Tortoises Start Out Small

2 tortoise (Sarah Floyd)

Nine Aldabra giant tortoises have hatched at Tulsa Zoo in Oklahoma! The hatchlings started to pip, or cut through their shells, on February 9. Several of the tortoise hatchlings are on now exhibit at the zoo. 

The hatchlings started out weighing a tiny 50 grams each, but they will get much bigger. Aldabra tortoises are the world's second largest tortoise species. The zoo has three adult males and two adult females. The adult male tortoises weigh nearly 400 pounds (181 kg), while the adult female tortoises weigh around 175 pounds (79 kg). Their ages range from 31 to more than 100 years old.

5 tortoise (Sarah Floyd)


4 tortoise (Aaron Goodwin)

1 tortoise (Sarah Floyd)

3 tortoise (Aaron Goodwin)

Photo credits: Tulsa Zoo / Sarah Floyd (1, 2, 4); Aaron Goodwin (3, 5)

The incubation period for these tortoises lasts from 95 to 120 days. Once the tortoises pip, it can take up to five days to fully emerge from the shell, and usually two to three more days before they are ready to be taken out of the incubator and placed on a substrate on exhibit. 

Aldabra tortoises live on the islands of the Aldabra atoll in the Seychelles. They are classified as Vulnerable on the International Union for Conservation of Nature's Red List of Threatened Species. 

Tulsa Zoo has now successfully hatched 109 Aldabra tortoises since it began its breeding program in 1999. The Tulsa Zoo is the only Association of Zoos and Aquariums-accredited institution that has an Aldabra tortoise breeding program, and the zoo is one of only two U.S. institutions to currently breed this species. Their first Aldabra tortoise hatchling emerged from its egg in the winter of 1999 and they have continued to collect fertile eggs every two to three years since that time. 

Endangered Chinese Big-headed Turtles Hatch at Prospect Park Zoo

1 turtle

Five Chinese Big-headed Turtles have hatched at the Wildlife Conservation Society’s (WCS) Prospect Park Zoo in New York City. These turtles, hatched in November, are the first to be successfully bred at a zoo accredited by the Association of Zoos and Aquariums (AZA).  

Chinese Big-headed Turtles are native to China, Cambodia, Laos, Myanmar, Thailand and Vietnam. They can grow to be about seven inches in length. They have skulls of solid bone that is so large in proportion to their bodies that they cannot be withdrawn into the shell for protection.

The species is classified as Endangered by the International Union for the Conservation of Nature. They are threatened by trade demand across its Asian range countries.

2 turtle

4 turtle

3 turtlePhoto credit: Wildlife Conservation Society / Julie Larsen Maher

See video of the little hatchlings:


In zoos, specific environmental and climatic conditions need to be manipulated in order to stimulate Chinese Big-headed Turtles to reproduce. Zoo experts were able to successfully recreate and document these conditions in the zoo’s propagation facilities, providing a road map for other organizations to successfully breed these turtles. 

Husbandry techniques were fine-tuned to promote breeding and successful incubation of the eggs. Before the breeding season, adults are isolated and placed in enclosures with environmental conditions that mimic the annual environmental cycles they would experience in the wild. These environmental cycles are important to the regular reproductive functions of the species. Room temperatures and lighting are adjusted depending on the time of year – colder and darker in the fall and winter, warmer and lighter in the spring and summer. During their “winter" the turtles hibernate. After awaking, males are introduced to females.

The Prospect Park Zoo is breeding this species as part of WCS’s global effort to save critically endangered turtles from extinction. The strategy draws on all of the resources and expertise across the institution – including its zoos and aquarium, Wildlife and Zoological Health Programs, and Global Conservation Programs – to take direct responsibility for the continued survival of some of the world’s most endangered tortoises and freshwater turtles.

“The success we are seeing at this point in our turtle propagation work is encouraging,” says Jim Breheny, WCS executive vice president of zoos and aquarium and Bronx Zoo director. “Our work on breeding endangered turtles utilizes the expertise found throughout the entire WCS organization as well as various partner organizations with whom we work.”

Learn more about turtle conservation after the fold!

Continue reading "Endangered Chinese Big-headed Turtles Hatch at Prospect Park Zoo" »

Second Endangered Keeled Box Turtle Born in Tennessee

Keeled Box Turtle Tennessee Aquarium 1.jpg

For the second time in Tennessee Aquarium history, the institution welcomed a rare Keeled Box Turtle hatchling. Like many other Southeast Asian turtles, Keeled Box Turtles have been over-collected in the wild for food and the pet trade. Several conservation organizations are working to protect the remaining wild populations from illegal trade, while zoos and aquariums are building assurance populations so the species does not go extinct if these animals disappear in the wild. Currently the U.S. population of Keeled Box Turtles at AZA-accredited zoos and aquariums is less than twenty animals, seven of which are at Tennessee Aquarium.

This baby was the only one to hatch out of seven eggs laid in July. The incubation time was 92 days at a toasty 82 degrees Farenheit and the tiny hatchling weighed just 0.41 oz (11.7 grams).

Keeled Box Turtle Tennessee Aquarium 2.jpg

Keeled Box Turtle Tennessee Aquarium 3.jpgPhoto credits: Bill Hughes / Tennessee Aquarium

The Tennessee Aquarium has one of the largest turtle collections on public display with more than 500 individuals representing seventy-five species. Their Senior Hereptologist, Bill Hughes, manages the Keeled Box Turtle Studbook and serves as the Species Survival Plan Coordinator for Spiny Turtles, Four-eyed Turtles, and Arakan Forest Turtles. 

Meet Thelma... and Louise, the Baby Two-headed Texas River Cooter

Cooter hero

The San Antonio Zoo welcomed a very special arrival to their aquarium: a two-headed (bicephalic) Texas River Cooter named Thelma and Louise! Thelma and Louise were part of a quartet of Texas Cooters hatched at the zoo on June 18 that made their public debut on June 25.

Craig Pelke, Curator of Reptiles, Amphibians, and Aquatics, notes that while this is uncommon, it is not unheard of in both the wild and captive populations. Bicephalic animals are actually twins that did not separate, resulting in two or more heads on one animal. Bicephaly occurs most commonly with snakes and turtles, without any accompanying health issues. Pelke said, “At this time, Thelma and Louise are doing well on exhibit and eating with both heads!”

Cooter size 2

Cooter duo

Cooter hand
Photo Credit: San Antonio Zoo

The San Antonio Zoo is no stranger to two-headed reptiles. A two-headed Texas rat snake named Janus lived there from 1978 until it passed away in 1995. Visitors can see the Cooter hatchlings in the Friedrich Aquarium located inside the zoo.

See more photos below the fold:

Continue reading "Meet Thelma... and Louise, the Baby Two-headed Texas River Cooter" »

Enadangered Turtles Hatch at Houston Zoo


A few months ago, ZooBorns reported on two endangered Madagascar Big-headed Turtles who laid a total of 33 eggs at the Houston Zoo.  Because the ground was too cold for the eggs to develop, the females were induced to lay the eggs in the safety of the zoo clinic.  On May 18 and 19, three of the eggs hatched!


Photo Credits:  Beth Moorehead/Houston Zoo (1); Tina Carpenter/Houston Zoo (2,3)

Though the remainder of the 33 eggs were infertile, zoo keepers say this result is not unusual in young female turtles who have just reached maturity. 

The hatchlings are currently behind the scenes until they are old enough to be on exhibit.  In the meantime, zoo visitors can see their older siblings, who hatched on September 15, inside the reptile house.

The Big-headed Turtles live in the moat of the zoo's Lemur exhibit.  Zoo keepers have created a sandy spot for the female turtles to dig in and lay their next clutch of eggs.

The hatching of these Turtles is significant because they are one of the world's most endangered Turtle species.  Found only on the island of Madagascar, they are traded illegally for use in traditional Asian medicine.

Prague Zoo is the First to Hatch Rare Turtles


Eleven tiny Brown Roofed Turtles hatched at the Czech Republic's Prague Zoo this month, the first of the species to hatch in any zoo in the world. 



Photo Credit: Tomáš Adamec, Zoo Praha

Brown Roofed Turtles are native to South Asia, including Bangladesh, India, and Pakistan.  They are listed as Near Threatened by the International Union for Conservation of Nature.

Many Turtle species in this region of the world are in decline.  They are often collected illegally for the pet trade and for use in traditional Asian medicine.  The Turtles' shells are ground up, mixed with herbs, and marketed as remedies for a wide variety of ailments, but there is scant evidence that these potions are effective.

Tiny Tortoises Hatch in Perth


The Perth Zoo in Australia had another successful season in their efforts to conserve Western Swamp Tortoises with 33 successful hatches. The zoo has been working hard since 1989 to help conserve this critically endangered species by rebuilding their wild population through a captive breeding and reintroduction program. Since the program's initiation, the zoo has hatched more than 800 tortoises, 600 of which have been successfully reintroduced to the wild. 

In order to help increase the hatching success, after tortoises lay their eggs, keepers dig them up and place them in incubators. They remain here for four to six months until the hatchlings emerge. This year, the zoo was able to capture rare footage of two tortoises emerging from their shells, which can be found below. After they are born, the hatchlings are weighed and marked with nail polish on their shells so that they can be individually identified.


Photo credits: Daniel Scarparolo / Perth Zoo

Hatchlings are raised at the zoo for about three years until they reach 100 grams in weight. At this point they are released into one of four sites that are managed by the Western Australian Department of Environment and Conservation to help boost the wild population. In addition, the zoo maintains an "insurance population" of 150-200 Western Swamp Tortoises in case of an unforseen  drastic decline in wild number.

See more photos after the fold!

Continue reading "Tiny Tortoises Hatch in Perth" »

Tiny Pancake Tortoises Hatch at Gladys Porter Zoo

Tortoise 1

Three Pancake Tortoises have hatched at Gladys Porter Zoo in Texas. The first tortoise began to pip on March 31st, followed by two more hatchlings on April 1st and 10th. 

Found on rocky hills and savannas of east Africa, Pancake Tortoises have unusually flat and thin shells. These flexible and agile tortoises are excellent climbers, and escape from predation by fleeing or squeezing into tight crevices instead of hiding in their shells. Due to habitat loss and poaching, they are listed as a vulnerable species by the IUCN.  

Tortoise 2

Tortoise 3

Tortoise 4
Photo credits: Gladys Porter Zoo

In the wild, Pancake Tortoises live in isolated groups, and many individuals may be found sharing the same rocky crevice. Males compete for females during the breeding seaon in January and February, and nesting occurs in July and August. Females generally lay one egg at a time, but may lay several eggs over the course of a few months. In captivity, females will breed year-round, with an incubation period of four to six months.  The tiny young are independent as soon as they hatch.

Coming Soon to the Houston Zoo: Baby Big-headed Turtles!

Houston Zoo MBHT Egg X-ray

Lurking in the murky waters of the Houston Zoo’s Lemur exhibit moat are seven critically endangered Madagascar Big-headed Turtles.  When the Turtles received their annual veterinary checkup, radiographs and ultrasounds revealed that two of the females had eggs. 

Houston Zoo MBHT-7572

Houston Zoo MBHT-7763a

Houston Zoo MBHT-7648a

Houston Zoo MBHT-7622a
Photo Credits:  Houston Zoo

The females would normally lay their eggs in nests excavated near the water’s edge, but the Houston Zoo staff determined that ground temperatures were too cold for the eggs to develop successfully.  Instead, the zoo veterinarian induced the females to lay their eggs in the safety of the clinic.  The two females laid a total of 33 eggs! 

The eggs were collected and placed in two separate incubators in the reptile house, with temperatures set at 28.5° Celsius (83.3°F) and 30.5° Celsius (86.9°F).  The Houston Zoo is the first in North America to incubate eggs from Madagascar Big-headed Turtles, and little data exists.  The staff expects the first hatchlings to emerge sometime in May.

Madagascar Big-headed Turtles are found only on the island of Madagascar, where they inhabit slow-moving streams.  Though they are among the world’s most endangered turtle species, they are still eaten for food and illegally shipped to Asia, where they are used for traditional Asian medicine. 

Rare Roti Island Snake Neck Turtles Hatch at Bristol Zoo

Turtle CU

The UK's Bristol Zoo announced some very good news: Six new Roti Island Snake Neck Turtles hatched and are all doing very well. They are just about a month old. It can take up to ten years for them to reach full adulthood.

The Roti Island Snake Neck Turtle has an extremely limited distribution and has been subjected to intense collection pressure for the international pet trade market, which has driven it into virtual commercial extinction. Recent field surveys have documented extremely depleted remaining populations still being impacted by persistent collection efforts, with remaining habitat areas also being reduced by agricultural development and conversion of swamps and marshland to rice fields.

The turtles will eventually be put out on display, although they’re still very young and fragile so are currently kept safely behind the scenes.



Photo Credit: Bristol Zoo