Giant Turtles – Working with the World’s Largest Freshwater Species

Turtle enthusiasts seem always to remain interested in even the commonest species. I’ve worked with world-renowned herpetologists who keep Sliders and private breeders who care for 2,000+ turtles (not a misprint!) yet find a place for Common Snappers.  I’m the same way…as I write, I’m watched by a Stinkpot that I acquired in 1969.  Yet there’s no denying the allure of 4 foot-long Giant Softshells, 200+ lb. Alligator Snappers, massive Painted River Terrapins and other rare giants like the turtle I’m holding in this photo (a Mata Mata rescued from a food market; the largest I’ve seen, perhaps a record). Today I’d like to share some experiences I’ve been lucky enough to have had with these and others. Don’t miss the chance to visit collections housing these amazing creatures; volunteer opportunities with field research programs are also sometimes available.

In 1985, while a reptile keeper at the Bronx Zoo, the opening of a 77,000 gallon Asian river exhibit (at Jungle World), allowed us to work with large turtles on a grand scale. Another unique opportunity came in 1997, with the seizure of nearly 10,000 turtles in Guangzhou, China. Many were sent to the USA, where I and others helped to place them in private and public collections. 

Painted Terrapin, Batagur borneoensis

The Painted Terrapin is among the rarest and most unusual of the world’s larger turtles. Ranging from Thailand to Borneo, it is listed as Critically Endangered by the IUCN.

The nearly 3-foot-long carapace is boldly marked with black stripes. Unique among turtles, males in breeding condition undergo an amazing color change…the head pales in color, and a bright red stripe emerges between the eyes! Some have theorized that this helps females distinguish them from Northern River Terrapins (see below), which sometimes share the same waters.

The Painted Terrapin’s broad, serrated jaws are mainly employed against plants, and I was amazed at their power.  Thick-stemmed kale, difficult to cut with a knife, was sliced like butter; they also snipped overhanging vegetation as soon as it grew within reach.

Northern River Terrapin, Batagur baska baska

The matriarch of my River Terrapin colony was a 70 pound female, estimated to be in her 60’s. Christened Miss Cunningham (long story!), she became one of the few of her kind to reproduce in captivity, and yearly rewarded us with fertile eggs.

The heads of the male River Terrapins darken during the breeding season, and white eye-rings develop. We were able to document a display during which males pumped their throats and possibly ejected water at one another.

Indian Narrow-Headed Softshell, Chitra indica

The mysterious giant softshells have always been something of a holy grail for me…none more so that the bizarre Narrow Head. I cared for several that measured approximately 3 feet in length, but 4 footers are known. There is even a possible record of a 6-foot-long animal (Annandale, N., and M. H. Shastri. 1914. Relics of the worship of mud-turtles, Trionychidae, in India and Burma. J. Proc. Asiatic Soc. Bengal n.s. 1914: 131-138).

I’ve handled thousands of snakes in my time, but have never come across one that could match this turtle’s strike-speed! Unfortunately, these shy creatures did not adjust to our sand-less exhibit, and were re-located to another zoo. The few Asian Giant Softshell Turtles (Pelochelys bibroni) that came my way also fared poorly.

Alligator Snapping Turtle, Macroclemmys temmincki

A 206 pound male that graced the Bronx Zoo’s Reptile House for many years was a highlight of the collection and my own turtle experiences.  He seemed very “fond” of his smaller relations, as he passed turtle scutes in his feces for quite awhile after we received him!  Please see the article below for more info.

Giant South American River Turtle, Podocnemis expansa

Three feet long and nearly as broad, these behemoths have long been in the Bronx Zoo’s collection.  However, “Podocs” need more attention …synchronized nesting has allowed poachers to decimate their numbers.

Those I cared for, some aged 50+, bred sporadically. One zoo reported that, when their Podoc pool was emptied unexpectedly, many turtles copulated when it was re-filled, despite the absence of any sexual activity for the previous 60 years. Apparently the 1 day “drought/rain cycle” was enough to stimulate them after all that time!

Malaysian Giant Turtle, Orlitia borneensis

The carapace of this black, highly-aquatic turtle is as highly domed as that of any tortoise. As with Cooters here in the USA, this may protect them from predation by crocodilians, and is likely “worth” the trade-off in swimming speed.

Malaysian Giant Turtles have only recently been bred in captivity (please see article below), and little is known of their natural history. An 80 pounder under my care moved along the bottom in Musk Turtle fashion, and was aggressive to other turtles. He consumed fish, crayfish and snails, but rejected fruits and vegetables.

Other Giants

I’ve run across a few unusually-large specimens of other species, including Mata Matas, Fly River Turtles, and several 60-75 pound Common Snappers.  Unfortunately, I missed the record-breaking 96 pound Florida Softshell…mishandling reportedly led to its demise. And working with Leatherbacks, and Galapagos and Aldabra Tortoises was awe-inspiring…please see the article below and look out for future notes.

 

 

Further Reading

Videos: Turtle markets,China

Malaysian Giant Turtle hatches

Florida Softshell feeding upon heron

Working with Leatherbacks

Turtle Survival Alliance

Alligator and Common Snappers

Painted Batagur image referenced from wikipedia and originally posted by Open Cage
Orlitia borneensis image referenced from wikipedia and originally posted by CowBongo