Ear-notching and translocating Malilangwe’s rhinos

Working for Malilangwe for the past 20 years and watching the rhino population grow over that time has been a privilege I don’t take for granted.

Since the introduction of our original rhinos in 1998, we have been able to identify every rhino individually. This has been possible through ear notching which involves clipping a unique pattern of notches into the outer rim of the ear.  It’s a system that cattle ranches have used for decades, and it allows anyone to identify an animal based on the position and combination of notches.

Being able to distinguish one rhino from another is like being able to recognise the faces of people around you. It opens a whole new dimension to understanding rhino behaviour and their relationships with one another. With this information we can calculate population size and demographics accurately. It also allows us to track how rhinos use the landscape, what they need to be healthy, who they choose to spend their time with and who to avoid, when a cow has a calf, and how that calf’s journey through life progresses. It’s powerful information.

Ear notching needs to be done before a calf leaves its mother, so that the maternal history isn’t lost. A calf can leave its mother any time from 20 months onwards when the mother gives birth to a new calf.

Being in a position where we can contribute black rhinos to a new population without jeopardising our own, is a great honour. It is something that rhino conservationists aspire to, but it is also bittersweet. Decades of monitoring individual rhinos builds an affection for each animal, and an understanding of this species’ ecology and their complex social relationships, making it very difficult to disrupt the status quo.

Aside from good security and quality habitat at the destination, successful rhino translocations are enhanced by the selection of very specific rhinos. While any group of rhinos may be captured to form the founders of a new population, selecting individuals that meet specific physical and social requirements is likely to improve the project’s success and dramatically reduce stress to rhinos in both translocated and donor populations. In addition to knowing the age and sex of individuals it is an enormous advantage if maternal bloodlines and social interactions between individual rhinos are understood. While a knowledge of the maternal histories helps to ensure that genetic diversity is maintained in both populations, understanding individual rhinos’ social relationships ensures emotional stability in a species that forms strong, yet selective relational bonds, a fact that is generally poorly recognised. By careful selection of individuals for translocation, population growth can be maximised without compromising genetic variation and social stability in both translocated and donor populations.

Malilangwe’s Animal Population Database is the powerhouse for our biological monitoring and research. Daily sighting details of all large mammals and raptors are captured first into field sighting books and then into the custom-built Access database that currently holds over 400,000 records collected over the last 24 years. Technology has made huge advances over the last two decades and the questions management needs answered have also become more sophisticated. For the database to continue providing quality information for research studies and for managers to base their interventions on, it is imperative that the programme is upgraded. This upgrade will allow for the capture of cell phone photographs tagged to field sightings, an option that wasn’t available 20 years ago, and it will also allow the database to interface with current Geographic Information Systems (GIS), modelling and statistical software. In the case of rhinos, the database allows us to track individual animals’ life histories, and while this data provides powerful new insights into the habits and ecology of rhinos, it ultimately guides our management of this species, enabling us to take informed actions that prioritise the welfare of the animals under our care.