Monkey matchmaking at RZSS Edinburgh Zoo

14/02/2018 in Edinburgh Zoo

Above: Diana monkey at RZSS Edinburgh Zoo

Approaching Valentines’ Day I thought it would be appropriate to share some behind the scenes tales of how we matchmake with certain species at RZSS. Most of the species held within accredited Zoos are centrally managed through studbooks or dedicated breeding programmes.

So what is a studbook I hear you ask? It is simply a record of all the individuals of a given species that are found in the captive population within accredited Zoos.  They contain lots of details on each animal such as birth date, sex, location and full ancestry. Studbook keepers like myself are responsible for keeping this data accurate and up to date to inform decisions when managing the captive population.

Currently L’Hoest’s and Diana monkeys are listed as vulnerable by the IUCN as they have a decreasing population trend mainly due to habitat loss and hunting. Studbooks and breeding programmes are vitally important to ensure that healthy populations of species can be sustained in Zoos.  Studbooks aim to maintain a high genetic diversity in the captive population by identifying which individuals should be matched to avoid the risk of inbreeding.

Above: Young Diana monkey at RZSS Edinburgh Zoo

Diana and L’Hoest’s monkeys have an established history at RZSS Edinburgh Zoo and we have had many successful births with both species . Both studbooks have been held by the RZSS for well over 20 years and are managed as EEPs which is the most intensive level of management for a zoo population. EEPs are usually applied to species of high importance that require a more intense level of management due to their conservation status. As well as the the EEP coordinator, these programmes also benefit from the input of a species committee, vets and nutritionists

The main goal of a programme is to get individuals breeding but there is more to it than simply putting a male and female together.  There are lots of criteria that are taken into consideration when matchmaking monkeys.

First we look at the genetics. Thankfully there are lots of software tools available now that allow us to ensure that the best genetic matches are made and help prevent inbreeding.  At that basic genetic level things are relatively easy; a computer can simply look at the data and tell us who should be matched with who.

This leads to the second stage when we consider how the demographics of a population is structured, mainly by age and sex. For example, we need to consider the sex ratio, the number of males and females and if the animals are of breeding age.  Out of 100 animals you may have 30 that are infants and 20 that are too old to breed so suddenly you have only half of the population to currently work with. If the sex ratio is skewed towards too many males then a population manager needs to start looking at managing this, for example by setting up bachelor groups. Age is important too, as we may not want to pair a juvenile male with an elderly group of established females or vice versa.

Above: Young l'hoest monkey at RZSS Edinburgh Zoo

The third stage is looking at how the animals behave. This heavily influences how a population is managed. Do they live in pairs, groups or are they solitary?  What is their reproductive behaviour?  When do they become sexually mature?  Often, we have to take into account an individual animal’s personality when making matches to ensure that they will get on well enough to live together and (hopefully) reproduce. Managing a studbook can be a bit of a roller coaster and doesn’t always go smoothly, a sudden death or falling out within a group can mean that we have to react to situations quite quickly. 

The final stage doesn’t involve the animals at all and comes down to working with people.  There are currently 63 L’Hoest’s monkeys across 14 European collections and 153 Diana monkeys in 39 collections across Europe, North America and Asia. There are often challenges working with colleagues spread across so many different countries ranging from logistical through to language and cultural barriers.  Despite the challenges,  this can also be one of the most enjoyable aspects, getting to know colleagues and the animals they look after. It is fantastic when we can collectively share in the success stories of new births, successful transfers and welcoming new zoos who want to be involved looking after these beautiful monkeys.  I’m pleased to say that the population of Diana and L’Hoest’s monkeys in Zoos is growing and we are currently achieving our aims with these species. 

Above: Donald Gow conducting primate research in the Budongo Forest, Uganda

Being a studbook keeper does hold a certain amount of prestige but it is also a lot of work and a big responsibility.  Luckily there is a lot of support both here at Edinburgh zoo and throughout the zoo community for the work we do.  There is a huge structure of dedicated individuals who are involved in breeding programmes throughout the world. To be working in this community is a great privilege and feels like being part of an international conservation family.

Going forward we hope to continue the growth of both monkey species in Zoos, in addition to developing more in situ conservation links and research for these wonderful primates.  We plan to establish a new breeding group of Diana monkeys here in Edinburgh and continue to grow our L’Hoest’s monkey group in their large new enclosure by the hunting dogs.  There is an exciting future for both species at Edinburgh Zoo! 

Wishing you all a Happy Valentines’ Day!


RZSS Budongo Trail and Living Links Team Leader

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