Working With The Rare Ryukyu Black-breasted Leaf Turtle
The Japanese government thought so highly of the unique and beautiful Ryukyu black-breasted leaf turtle it was designated as a National Natural Monument on June 26, 1975
The Japanese government thought so highly of the unique and beautiful Ryukyu black-breasted leaf turtle (Geoemyda japonica) that the turtle was designated as a National Natural Monument on June 26, 1975 (who knew that a turtle could be classified as a monument?). This means that in Japan, handling of the Ryukyu black-breasted leaf turtle, including its purchase, sale and captive maintenance, are all strictly controlled by law. Geoemyda japonica is also listed on the 1991 and 1999 Japanese Red Lists, it is listed as endangered on the IUCN Red List, and it was recently designated an Appendix II species on the Convention on International Trade in Endangered Species (CITES).
Geoemyda japonica occurs only on the Ryukyu Islands of Japan, specifically on Okinawa, Kume and Tokashiki. Although found rarely on other islands in the Okinawa archipelago, these occurrences are thought to be due to introduction by humans. As with many turtle species, fossil records indicate that the Ryukyu black-breasted leaf turtle was more widely distributed in the past than it is today.
The Ryukyu black-breasted leaf turtle is kept in captivity in Asia, Europe and the United States, albeit rarely — a consequence of the significant protection within the turtle’s home range. It was imported to the U.S. more frequently at around the turn of the century, usually with paperwork that claimed the turtles were Vietnamese black-breasted leaf turtles (G. spengleri), which was considered a subspecies of G. japonica as recently as 1992, and even the same species prior to 1935. Anyone who has worked closely with both turtles knows how distinct they are from one another in their appearance, behavior and husbandry needs in captive situations.
Due to its beautiful appearance, as well as the species’ rarity, the Ryukyu black-breasted leaf turtle is highly coveted by collectors and turtle breeders. This puts pressure on wild populations despite Japan’s efforts at protecting them and, unfortunately, the G. japonica found offered for sale around the world are likely to be illegally smuggled turtles. Happily, though, there are dedicated turtle breeders who are breeding the turtle in captivity with some success.
The Beautiful Ryukyu Black-Breasted Leaf Turtle
The Ryukyu black-breasted leaf turtle attains a straight carapace length (SCL) of roughly 6 inches. It has a relatively elongate, slightly domed shell with a flattened peak. There are three well-developed keels running down the shell, with the vertebral keel being the highest. The marginals are serrated, which diminishes over time. The carapace coloration may be dark orange, tan, or reddish, but it’s often brown overall, and the keels are usually accompanied by attractive black markings.
The plastron is large and almost entirely black. Geoemyda japonica possess axillary scutes, which are located just behind the front limbs. These little scutes might not seem remarkable, but they are actually used by customs agents as the most straightforward and accurate method for quickly distinguishing this rare species from other closely related turtles, such as G. spengleri.
The handsome and average-sized head has a hooked beak. Both head and neck are adorned with beautiful orange and red stripes, and the sides of the head have an attractive yellow streak that extends behind each eye. The exposed surfaces of the limbs are protected by large scales, which can be brightly colored, and the limbs and tail are always darker in color.
Ryukyu Black-Breasted Leaf Turtle Care in Captivity
Many keepers of Ryukyu black-breasted leaf turtles maintain theirs in groups, but there are some drawbacks to keeping G. japonica communally. Keepers may not find eggs before other turtles in the enclosure discover and eat them. And, as with other reptiles that are kept in groups, submissive G. japonica may be less likely to eat and behave naturally.
We house adult G. japonica singly in 30-gallon Rubbermaid tubs made of opaque plastic and measuring 31 by 20 by 17 inches. A substrate mix of organic topsoil and peat moss with a top layer of cypress mulch provides a naturalistic living surface that holds moisture without getting moldy. Oak leaves, sphagnum and live mosses are added, as well as a hide to provide aesthetic appeal to the enclosure. A water dish is provided, too; my only rules are that it be BPA-free, that the turtle can easily enter and exit the bowl, and can fully submerge while inside it.
The tubs help to contain humidity, and their opaque walls help to reduce stress because the turtles can’t see through them. They’re easy to clean, and we drill holes in the bottoms for drainage. It can rain virtually every day during the Ryukyu Islands summer, and proper drainage in G. japonica enclosures is a must. The substrate should be kept moist, but not flooded, and the addition of live plants, such as pothos, not only reduces the risk of stress-related health problems by providing the turtles with security, but aids in maintaining humidity during the warmer parts of the year.
Indoor temperatures for adult turtles should never be more than 90 degrees Fahrenheit for long periods, or lower than the 40s. Keepers should aim to keep their turtles in the low 80s during the summer and the high 50s to 60s during the winter, though they should not be wet in cooler temps.
Hides For The Black-Breasted Leaf Turtle
Perhaps the most important element in a Ryukyu black-breasted leaf turtle enclosure is the inclusion of a hide. Practically all reptiles kept in captivity require suitable hides in order to feel secure and free from stress, but this secretive turtle takes this need to a new level.
Researchers know that in the wild, Geoemyda japonica is best found by sticking their hands, and perhaps even an entire arm, into holes in the sloped mountain terrain where this species resides. Individual turtles are reported to return again and again to the same burrow, sometimes remaining in the burrow, or at least close to it, for as long as seven months.
We have found the best way to provide a naturalistic hide for this species is by using long pieces of cork bark placed on top of the substrate. These replicate the lengthy burrows so often used by G. japonica in nature. Additionally, sturdy terrarium plants, like pothos, can grow over a cork bark hide, adding to the beauty of the enclosure and comfort of its inhabitants.
Perhaps the best reason to provide a hide made of cork bark is its porous nature. During watering of the enclosure, this allows water to quickly seep into the interior of the hide, increasing humidity and alerting the turtle hiding inside that it is time to get become active. The Ryukyu black-breasted leaf turtle is a crepuscular species, meaning that it is active in the morning and just before dusk in order to avoid the heat of mid-day, but it is also known to become active during wet weather.
Maintaining Ryukyu black-breasted leaf turtles outdoors is certainly possible and has been done successfully by some of the most accomplished G. japonica keepers. However, this should only be attempted where the weather would make doing so sensible, and this does not include the majority of the U.S. because the average winter temperature in the Ryukyu Islands is 68 degrees.
If your local weather does permit you to keep G. japonica outdoors, as with indoor keeping, the enclosure should be very well planted with long hides — one for as many turtles as there are in each enclosure. During the warmer parts of the year, the enclosures should be sprayed with water to simulate the heavy rains experienced in the Ryukyus, and remember, excellent drainage of the enclosure is of paramount importance. A perfect outdoor enclosure for Ryukyu black-breasted leaf turtles would include some rocky and/or sloping terrain to replicate the species’ mountainside habitat in the wild.
What Foods To Feed The Black-Breasted Leaf Turtle
Geoemyda japonica eats a wide variety of foods. As with many captive omnivores, food that moves is always preferred. Thoughtful keepers must be mindful of this fact, and ensure that their charges are also provided with the most balanced diet possible. We feed our turtles a diet that is identical to other terrestrial Asian species, such as flowerback and Chinese box turtles of the genus Cuora.
Protein, fruits and vegetables should all be present in the Ryukyu black-breasted leaf turtle’s diet, in addition to calcium and vitamin supplementation. A variety of protein is offered to our animals, including boiled chicken, boiled or cooked ground turkey, frozen/thawed shrimp, chopped earthworms, pinky mice and scrambled eggs.
Vegetables we offer include sweet potato, green zucchini, summer squash, pumpkin, bell peppers and a variety of mushrooms. Wild mushrooms are not recommended, but any purchased for human consumption should be safe for the turtles. Fruit such as blueberries, strawberries, raspberries, blackberries, mango, banana and tomato are all appreciated and safe to offer.
Food should be finely chopped and mixed together; we invested in a food processor to make this much easier. The turtles are more likely to veggies they might otherwise eat around if they are chopped finely and mixed with the fruit and protein sources. It’s fun to watch these delightful turtles eat all the food while trying unsuccessfully to pick out their favorite types.
Breeding the Ryukyu black-breasted leaf turtle, as well as incubating and hatching the eggs, if you get that far, is tremendously difficult. Cooling the turtles during the winter months is thought to contribute to successful propagation, and G. japonica can tolerate winter temperatures into the 40s as long as they are kept dry. They should be exposed to such low temperatures gradually and only temporarily, however.
We incubate eggs on a 50/50 mixture of peat moss and vermiculite, with long-fiber sphagnum moss on top to cover the eggs during incubation. The eggs are kept fairly wet compared to the eggs of many other chelonian species, but not so wet that there is water pooling anywhere in the incubation container. We choose to incubate our eggs at fluctuating room temperatures in warm, low-traffic areas of the house, where temperatures range from the mid 70s to the mid 80s Fahrenheit. This usually leads to incubation periods that last about 82 days.
Some of the most prolific breeders of G. japonica keep their adult turtles outdoors year-round, allowing them to breed and lay eggs, with eggs later hatching from the ground. Then they simply collect fresh hatchlings within the adult enclosure!
We keep individual hatchling Ryukyu black-breasted leaf turtles in 6-quart plastic containers within a rack system. Each container measures 131/2 by 8 by 5 inches. We provide light via a movable fluorescent fixture that is hung vertically down the front of the rack. This provides a natural day/night cycle and helps maintain humidity and predictable temperatures — all perfect for steady growth.
Each container is full of clean sphagnum moss and about a half inch of water, with a half of a plant pot, cut vertically, that serves as a hide. Live pieces of pothos or artificial plants are added to provide a touch of naturalistic decoration. Turtles are kept individually in these small enclosures for approximately their first six months, before they are moved to 18-quart covered tubs measuring 18 by 12 by 7 inches. These have clear covers, and heat is provided from beneath. With these juvenile enclosures, as well as the hatchling enclosures, the goal is to create an environment in which condensation can be seen on the walls of the enclosure. The turtles are moved to the terrestrial habitats previously described when they weigh about150 to 200 grams.
Offset the Damage
If you are a turtle breeder who is looking to add the Ryukyu black-breasted leaf turtle to your captive-breeding program, be sure to put forth the proper effort needed to familiarize yourself with the animals being offered for sale and the people selling them. If a deal seems too good to be true it probably is, and you should proceed with caution. Many well-meaning keepers have purchased turtles only to find out afterward that their animals were probably wild caught and required unexpected veterinary care, or worse.
It is not likely that efforts to breed G. japonica will soon be seen as a conservation movement, because Japan never really let any turtles out of the country legally. I would argue, however, that the demand for the Ryukyu black-breasted leaf turtle remains unsurprisingly high, and the success of private breeders could help offset the situation that is currently leading to the illegal poaching and smuggling of this species. Dedicated champions need to step up and attempt to breed this species, to offset illegal practices that threaten the future of this unique and beautiful turtle.
Anthony Pierlioni is the senior director of theTurtleRoom, an official Conservation Partner of the Association of Zoos and Aquariums. He recently wrote a book on Geoemyda species as part of Living Art Publishing’s Turtles of the World series, and he is also the co-host of the Pondcast, dedicated to reptiles and amphibians and the people who love them (listen at theturtleroom.com). Anthony has also developed the Second Chance Project, which gives people with disabilities a chance to build skills and confidence by caring for critically endangered turtles. To watch a video about the Second Chance Project, go to http://bit.ly/2vI7vQ9.