The amazing history of the Bornean River Turtle

In December of 2001 thousands of turtles were confiscated by the Hong Kong authorities. These turtles were stacked on top of each other in shipping containers on a ship headed for China. There were so many turtles that finding shelter for them just in the Hong Kong region was inadequate and ultimately no less than 4200 turtles left for America and Europe. Despite all of the efforts of caregivers all over the world thousands of turtles still died due to the poor health condition of the turtles. Many, many turtles were loaded with fish hooks and attempts to get them to eat were not always successful.

Royal Burgers' Zoo as shelter

The turtles that were sent to Europe were, at first, taken in by Diergaarde Blijdorp in Rotterdam and by Burgers' Zoo. After the period of quarantine many of the surviving turtles were sent to various animal parks in the Czech Republic, Spain and Portugal. A few Bornean River Turtles (Orlitia borneensis) stayed here in the Mangrove. This species was not yet represented in European zoos. Because all of a sudden there were a few dozen turtles in the European population, it was decided to set up a genealogical registry (European Studbook) for this species. The Zoo in Prague accepted the coordination.

Special turtles

Orlitias are special turtles for several reasons. It is the largest freshwater turtle of Southeast Asia, which can get up to a metre long, including the head and tail.

The shell of the back (carapace) of the adult species is smooth and has a brown to blackish colour. The underside (plastron) has a pale yellowish brown colour. The adult turtles have a dark head, while the young ones have a more mottled head with a thin pale line from the corner of the mouth to the back of the head. They are capable of diving deep and staying under water a long time, they also like to lie still and unnoticed in a little puddle of mud. Regretfully, many turtles are still used for consumption and considered a delicacy in China. That is the reason these turtles are considered seriously endangered.

Challenge

So, unknown to the public, we had a number of special species in our Mangrove. After the turtles had recovered completely, we faced our next challenge: how could we breed this species? After three years of patience we were rewarded; at the end of February eggs were found on the little beach in the Mangrove. These eggs were placed in a moist container in the incubator. How long the breeding time was and what temperature or moisture the eggs needed was still unknown at that time. Finally, after five months, two turtles hatched from the eggs. What was even sweeter, was that this same year seven baby turtles were discovered in the Mangrove! One morning a caregiver found the little turtles swimming between the older ones.

Inventory

In the mean time quite a few years have passed and it became time to inventory our group again. This inventory consists not only of weighing and measuring the turtles, but also of checking them carefully. Is the paper administration still current on how many of the species are ultimately in the animal quarters? Also, is the sex of the turtles still correct? At a young age it is hard to see whether it is a female or a male turtle. The Studbook holder from Prague also wanted to have some pictures of the shells of the species to include in a research about determining the sex on the basis of the shell. And so it happened: on December 4, 2015 we caught all the turtles in our Mangrove, including the "snake-necked" turtles (now that we had chosen this path anyway..). The turtles were weighed and measured. In addition, pictures were taken and a tiny bit of blood was collected from the river turtles for DNA research. The drawing of this blood is not without risk, because it must be done just below the shell above the head. You have to make sure to stay away from the head, because the turtles can bite very hard. In fact, it could even cost you a finger!

Answer to questions

We do know how we got these turtles, but we still do not know exactly where they came from. Perhaps DNA research can provide this answer in the future.

Luckily the inventory showed that all turtles that were present appeared to be in good condition. We only had to change the sex of one turtle in our administration. Gradually we are getting to know this special, giant and strong species, which is living a mysterious life in slow flowing rivers.