Saturday, 31 March 2012

Turtles and Tortoises 3: Boxed into a corner

One of the most serious conservation issues today is the catastrophic decline in recent years of the various species of turtle to be found in south-east Asia. Turtles have been used for local consumption for many years, but urbanisation (which destroys habitat), agricultural development, pollution, and above all over collection from the wild for the expanding food markets of China has placed all of them on the critical list. Many species are in fact only known from specimens found in food markets, and probably have very restricted ranges if they still survive at all.

Among these threatened species are the various Asian box turtles of the genus Cuora. As with their more well know American equivalents, the various box turtles placed in Terrapene, they have a flexible hinge on the plastron (the underside armour) which enables them to seal themselves completely inside their shell.. At present at least ten species have been described, many with several subspecies, and the range of the genus extends from India across Malaysia and north into Vietnam and southern China.

Cuora favour damp habitats, and many species are semi-aquatic, and in past centuries many forms could be found around human habitations, as flooded rice fields were ideal for them. Although they live in areas with high humidity and temperatures, the more northerly and high altitude forms seem to be tolerant of low winter temperatures, although whether they go into true hibernation is unclear.

As with most semi-aquatic chelonians, Asian box turtles are omnivorous, but in most species the adults mostly rely on vegetation. They will happily consume snails, insect larvae, small fish or frogs if they get the chance however. They are not very prolific, laying only a few eggs each year, and as a result are extremely vulnerable to exploitation, especially as this mostly involves breeding size adults. The growth rate and lifespan are unknown, but it is likely they take at least 7 or 8 years to reach maturity and have a lifespan of decades.

At Bristol we have five species of Cuora on show and have bred several of them. As part of our commitment to turtle conservation, one room of the reptile house is a dedicated turtle breeding room. This is climate-controlled and contains the large plastic tubs we use for housing the animals off-show. Each tub is designed to give a combined water and planted land area and houses a pair or trio of adults of the various species. Currently our collection comprises the following:

Cuora amboinensis SE Asian Box Turtle 1.2 (Vulnerable)

Cuora flavomarginata Yellow-margined box turtle 4.2.4 (Endangered)

Cuora galbinifrons Indochinese box turtle 3.3 (Critically Endangered)

Cuora mouhotii Keeled Box Turtle 2.1 (Endangered)

Cuora trifasciata Chinese Three-striped box turtle 0.0.2 (Critically Endangered)

We usually get a few eggs each year, but the breeding season is only just starting. I will update with any results later this year.

Finally, a plea to anyone who keeps these turtles themselves – it is absolutely vital that any adults of any of these species be in a breeding set up. If you have one on its own, even if it is a family pet for many years, please contact a turtle society (there is one in most countries) and see if you can match it up with a mate.

Next week, another rare turtle, this time from Vietnam.
(images from wikipedia)


  1. Great blog, informative and up to date. Bookmarking your page. Thanks and more power!

  2. Great news - a baby Vietnamese Box Turtle (Cuora bourreti) has hatched, only the 2nd breeding in Europe. Unfortunately off-show at present, but check the Bristol Zoo website for photos.