The Complexity of a Bull Transfer

An extraordinary transport operation was planned at Planckendael ZOO in Mechelen: the Asian elephant Upali was to be brought here from a zoo in France. The arrival of this 31-year-old bull was crucial to the European species conservation programme that safeguards the genetic diversity of this endangered species.

In the wild, Asian elephants live in close-knit female herds, but when the males reach maturity, the bachelors leave to live either alone or in groups of other males. ‘To prevent inbreeding and ensure the species’ survival, elephant herds in zoos are composed with the greatest care,’ explains Sander Hofman, Animal Care Manager at Planckendael ZOO. ‘So, our strategy is to keep the females where they are and periodically transfer the males from one herd to another.’ These bull transfers are part of the European Endangered Species Programme (EEP), through which zoologists determine which animals are the best genetic match for breeding.

After Chang and Kanvar, Upali is the third bull elephant to arrive at Planckendael ZOO since the start of the breeding programme. ‘The arrival of a new male is always an exciting moment’, adds the ZOO’s Head Keeper Ben Van Dyck. ‘Each elephant has its own personality, which can change the herd’s dynamics completely.’

A Logistical Tour de Force

An adult bull elephant is a strong, intelligent animal that can weigh up to six tonnes. What’s more, during musth – the period of heightened testosterone – he can be highly unpredictable. All this makes a transfer like this a complex operation, with months of preparation taking place behind the scenes before a bull even arrives at his new zoo. ‘We handle all the arrangements and make sure every last detail is taken care of, right up to the moment the truck carrying the crate drives through the gates,’ explains Suzy Janssens, Transport Coordinator at Planckendael ZOO. ‘An operation like this involves lots of people: zookeepers, vets, the EEP coordinator, and so on. Every aspect, from transport logistics to paperwork, has to be exactly right, regardless of the species involved. And when it concerns an endangered species, it’s even more complex because you also have to take CITES into account.’

CITES is the treaty that regulates the international trade in endangered plants and animals. Each time an animal on the endangered species list, such as the Asian elephant, is relocated, official documents are required to confirm that the transport is legal and responsibly managed. ‘It serves as a passport, meticulously recording every step in the life of an endangered animal. In addition, health certificates and keeper sheets are prepared. These contain information about the animal’s behaviour, training and habits. We even arrange overnight accommodation for the keepers accompanying the animal.’

On top of that, transferring elephants presents an additional challenge as they are one of the few species that remain standing during transport. To ensure a safe and stable journey, the transport crate must be robust and carefully balanced, and the elephant undergoes crate training to familiarise it with the crate and encourage it to enter voluntarily.

In parallel with the logistics operations, animal care and veterinary teams also work at full speed, overseeing the necessary medical checks: from vaccinations to a trunk rinse. The keepers at Planckendael ZOO also remained in close contact with their colleagues at the other zoo for several months in preparation for the transfer. ‘Each animal is unique, with its own personality, needs and preferences’, says Ben Van Dyck. ‘So, last August, our keepers visited the zoo in France to learn all they could about Upali.’ Meanwhile, all protocols in Mechelen are being reviewed and adjusted where necessary: from door operation plans to the division of tasks during transport.

Why a Transfer Was Necessary

Although Kanvar seemed perfect for breeding on paper, in practice, things didn’t turn out that way. ‘If a bull is introduced to a herd of adult females too soon, if he isn’t the right size or weight, or if he doesn’t fit socially within the group, he may not be accepted for mating,’ explains Sander Hofman. ‘In such cases, it’s important that we, as members of the EEP, can respond quickly.’

The EEP closely monitors the fertility of female elephants. Keepers collect dung samples and send them to the herd book keeper’s laboratory for analysis. These samples help determine whether the females have a healthy, regular cycle, whether the bull mates at the optimal time, and if any of the cows are pregnant. ‘This is crucial’, Hofman continues. ‘If a female elephant goes too long without conceiving, she risks “flatlining”: a conditioning that could lead to permanent infertility.’

So, a bull transfer not only contributes to genetic diversity but also to the health and fertility of the cows. ‘Bringing in experienced breeding bulls like Upali increases the chances of successful pregnancies and helps us keep the Asian elephant population in Europe healthy and thriving.’

Upali’s Passport

Upali is almost 31 years old, weighs 5½ tonnes, and fits well within the EEP population. ‘He has already earned his stripes with other females at different zoos,’ recounts Ben Van Dyck. ‘He has fathered 14 calves and even has three great-grandchildren.’

With his experience as a stud, Upali is a valuable asset to the European breeding programme. Expectations are high. Kai-Mook and May Tagu are the prime candidates to conceive with Upali. ‘This is crucial for their health as well as for the genetic diversity of the population. However, patience is required: an elephant’s gestation period lasts 22 months.’

Een domino-effect in Europa

A bull transfer is rarely without repercussions elsewhere in the international zoo community. The arrival of Upali at Planckendael ZOO is just one piece in the larger jigsaw puzzle being assembled all over Europe. When one bull is relocated, it creates space elsewhere, triggering a chain reaction. ‘The EEP coordinates these transfers to ensure that every piece of the genetic puzzle fits perfectly,’ explains Hofman. ‘Dozens of zoos cooperate to safeguard the conservation of the Asian elephant.’

For Planckendael ZOO, Upali’s arrival marks the start of a new chapter. While the bull settles into his place within the herd, a wealth of knowledge is gathered and shared behind the scenes. Each transfer brings new experiences that help make the next one safer and more efficient.

Research and Nature Conservation Hand in Hand

Beyond coordinating bull transfers for breeding purposes, Planckendael ZOO is deeply committed to scientific research and nature conservation initiatives that benefit the Asian elephant. One of these was helping to build elephant corridors that connect the animals’ habitats and help prevent conflicts between elephants and local communities in Kerala, India. Planckendael ZOO also plays a pioneering role in international research on elephant herpes: from a promising vaccine trial in young elephants to a major breakthrough in developing treatments. In this way, animal care, science and nature conservation are inextricably linked.