Species Info and Photos
First captive breeding of Zhou's Box Turtle, Cuora zhoui , in North America
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David S. Lee and Leslie M. Levine
The Tortoise Reserve
All photos by Alex Siess
The Zhou's box turtle, Cuora zhoui , was not described until 1990. It is endemic to China but its exact distribution is unknown. All specimens to date have been recovered from live food markets in Guangxi and Yunnan Providences. The habitat of this turtle is also unknown, but the market animals are suspected to have been collected in remote hilly streams. While the population status is not known, based on the small numbers found in markets, the recent discovery of the species, and their absence from live food markets and the pet trade for a number of years, this Cuora was obviously a rare localized species and it is now believed to be extinct in the wild.
An adult pair of Cuora zhoui was donated to
the Tortoise Reserve in early 2003. After several months of quarantine
and routine medical treatments, they were brought to our North Carolina
captive breeding facility in March 2003 and introduced to an enclosure
constructed specifically for this species. They measure 170 mm SCL by 117 mm
(male) and 170 mm SCL by 126 mm in width (female). Weights varied from
686.5-788 grams (female) and 705-709 grams (male).
Though believed extinct in the wild, there are small numbers of Cuora zhoui
in captivity. Inventories suggest that there are approximately 35 captive
pairs in the United States and a similar number in Europe . Nearly all
specimens are held by the private sector. The fate of this species appears
to rest entirely on successful captive breeding, maintaining genetic
diversity in subsequent generations, and commitment for long-term
maintenance of captive populations. All prior captive breeding
of this species, to our knowledge, are the achievement of private turtle
hobbyist and conservationist Elmar Meier of M ü enster, Germany, who is
affiliated with the International Species Conservation Center at Zoo M ü
enster and who generously shared with us information about his
successful husbandry practices with this species. We report the first
captive breeding of this species outside of Elmar Meier's German facility.
Of note is that the husbandry methods associated with this North American
breeding are quite different from those used by our German colleague.
The adult enclosure in the greenhouse is in
a back corner that remains cooler than the rest of the building, and it has
less solar exposure at all seasons, The pen is 7 by 7 feet on the longest
sides but because of an angled front side is only about 35 square feet in
total area (for the most part, non-reptilian measurements are provided in
English units to perplex scientists unable to cope with inconsonant
descriptions and to confuse our European counterparts). Centered in this pen
is a 50-gallon (100 liters) oval Rubbermaid ® tub buried to the level of the
substrate. The tub measures 52" by 29" and is 11" deep. Because of a cooling
fan, maximal summer daytime air temperatures in this section of the
greenhouse are about 85 ° F. Minimal winter temperatures are 65 ° F. The
water temperature is about 5 degrees cooler than the average air in the
summer, and about the same as the minimal winter temperatures. The pen is
landscaped with various plantings including a ground cover of sphagnum moss,
black-stemmed elephant ear, prayer plant, an Asiatic terrestrial polpody,
jewel orchids, and a small papaya tree. Several hides are available for the
terrestrial turtles. The gravel-bottomed pond has an emerging cypress log
(for both basking and maintaining water pH), and a few water hyacinths. It
receives direct sun less than 2-3 hours a day.
Several additional temperate/sub-tropical turtles share the same pen (1.2
Geomyda spengleri , 0.1 Cuora pani , and 0. 1 C. galbinifrons ). Except for
the Cuora pani the other turtles remain on the land portion of the
enclosure. For the first several months, the male C. zhoui was housed in a
35-gallon aquarium inside the enclosure and was introduced to the female for
only a few hours a week. The male was allowed permanent access to the
female once it became apparent that he was not overly aggressive and that
the female took advantage of available retreats to escape his advances.
These Cuora feed both day and night. Their main diet is floating fish
pellets (36% protein) but they are also fed small live fish, earthworms, and
small crayfish. Snails, dragonfly larvae, and aquatic plants that
volunteered in the pool are probably also consumed. Once a week, sections of
bananas are placed near the edges of the pool and within minutes the C.
zhoui emerge from the pool and eat the bananas. If disturbed, they will
often carry the banana wit h them when they crawl back into the pool. Late
in the afternoon sun hits one side of the pool for about an hour and
occasionally these turtles will bask if there is no activity in the
greenhouse.
Zhou's box turtles are shy, and remain submerged in the water, typically
hiding under a cypress log, throughout much of the day. When found
undisturbed they are seen lying on the bottom with about 1/3 of their head
extended above the water surface. Like other turtles in our collection, they
are handled as little as possible and they have not become accustomed to
people.
Mating was observed on a number of occasions starting as early as 22 March
and continuing at least through early June. In late May 2004, the female was
found on a number of occasions out of the water and was believed to be
looking for a nesting site. On 5 June the pen, pool, and filter were given a
complete cleaning. At this time the female was palpated and eggs could be
felt. Two sand areas were added to the enclosure to serve both as nesting
sites and as focal points for searching for the eggs. One was heated with a
ceramic heater while the other was not heated. Four eggs were discovered
about 4 inches below the surface of the sand in the shaded, and unheated
nesting area on 19 June. The eggs were placed in an incubator on 22 June and
they banded within a couple of days. They were very consistent in size and
measured 48.9-49.1 x 23.9 mm. They were not weighed, but slightly exceeded
10 grams. Incubation temperatures were fluctuated between 78 ° F at night
and 85 ° F during the day. After 90-91 days of incubation two eggs hatched
between 16-17 September, the other two eggs spoiled early in the incubation
process and when opened showed no indication of development. The first young
turtle emerged with an extremely extended yolk sac, and soon died presumably
because of infection resulting from the extended yolk. The second one
hatched ca. 38 hours later. The absorption of yolk appeared normal on the
second individual. Both young were kept in a non-abrasive, light-free
container in the incubator for their first two days.
The failure of two eggs to hatch and the death of one young within 48 hours
of hatching suggest that the eggs were not incubated properly. In the future
we plan to incubate the eggs with ambient outdoor temperatures in the same
way in which we incubate eggs of Cuora flavomarginata as well as Clemmys and
other aquatic and semi-aquatic temperate turtles.
Description of young: The nose is extremely
pointed, and the tail is proportionally long. Legs and tail black. The head
is black dorsally. The carapace is also black, and the posterior marginals
are slightly serrated. The bridge and adjacent ventral marginals have small
yellow blotches, and the plastron is black with pale thin yellow-orange
marking on the anterior and posterior edges and broken elongated
yellow-orange marking on the mid seam. The net result is a yellow smiley
face on a black plastron. No hinge is apparent. The weights ranged from
9.4-10.1 grams and shell measurements averaged 33mm SCL by 29.5 mm in width.
By mid-October 2004 the single surviving hatchling appears healthy and is
growing (13 % increase in mass).
The single hatchling is in an indoor 10-gallon aquarium with a slope
allowing for variation in water depth (0-3/4"). One end is covered with an
inch of live sphagnum the other is open water with a small cypress root
separating the two sections. The tank is illuminated 24 hours a day with a
full spectrum florescent light suspended 12 inches above the water surface
and substrate. The room in which the tank is housed remains about 80-85 ° F.
The hatchling spends 90% of its time in water, but beneath the sphagnum or
the log. The remainder of time is invested in patrolling the open water.
Within two days of hatching, it fed on small mealworms and mosquito larvae
and pupae. Finely cut earthworms and fish pellets were initially refused.
Like other first year Cuora maintained in adjacent tanks, it also probably
selectively feeds on insects attracted to lights and subsequently fall into
the aquariums.
This box turtle is but one of a number of highly endangered species of
turtles indigenous to Southeast Asia . As part of a long-term conservation
effort, members of the Asian Turtle Consortium are committed to captive
management of Asian turtles. Through captive breeding, they hope to be able
to maintain genetically viable stocks of species such as Cuora zhoui that
have become highly endangered and, in a number of cases, extirpated from the
wild. The Tortoise Reserve is one of the founding members of this private
sector non-profit conservation organization. The Asian Turtle
Consortium works independently of, but in cooperation with, all governmental
agencies and other conservation groups. The 100-member organization oversees
a composite collection of over 90 taxa of adult Asian turtles and annually
produces thousands of young. Several programs are now in place where captive
bred young are being returned to countries in Southeast Asia .
We thank the late Dr. Barbara Bonner of the Turtle Hospital , who
accompanied the turtles when they were transported to the Tortoise Reserve.
She is responsible for initially assessing and stabilizing their health and
donated a number of the other turtles inhabiting the same enclosure. Mike
Lowe, NC Vet School, has helped to oversee the health of the adults and
hatchlings. Dr. Charlie Innis pit tagged, examined and medicated the turtles
immediately after acquisition. In June 2004 the greenhouse facility
where these Cuora and other Asian turtles are maintained was named in honor
of Dr. Bonner.
(Lee) The Tortoise Reserve, Inc. P. O. Box 7082, White Lake, North Carolina
28337 Torresinc@aol.com