11 08/11/2018

The EAZA Group on Zoo Animal Contraception celebrates 10 years!

Established by Chester Zoo’s Head of Applied Science, Dr Sue Walker in 2008, the EAZA Group on Zoo Contraception (EGZAC) celebrates its 10th year anniversary this year.

One of Chester Zoo’s six specialisms, Conservation Breeding and Management, focuses on managing reproduction in ex situ populations of animals to increase their reproductive success.  EGZAC plays an important role in that process.  

Sue Walker, Head of Applied Science at Chester Zoo and co-chair of EGZAC explains:

EGZAC was established to support conservation breeding in the EU zoo community. Managing populations is not always about successful births - it’s sometimes about controlling reproduction to ensure healthy and genetically diverse populations.

EGZAC is supported by a global network of reproductive specialists and is responsible for systematically collection of detailed contraception data from the zoo community. Together these resources enable EGZAC to help others make informed decisions on contraception and support conservation breeding programmes worldwide!

EGZAC birthday cake

A history of conservation breeding

As good zoos evolved from places simply of spectacle to leading conservation organisations and stricter regulations were put in place to protect endangered species in their natural habitat, zoos became responsible for safeguarding ex situ populations.  As a result, zoos had to ensure that their populations of animals were self-sustaining.  As solely breeding animals from a single zoo with one another would quickly limit the genetic health of the zoo population, they established collaborative breeding programmes in which animals were transferred between zoos for breeding.

Deciding which animals are best matched is largely decided upon by looking at the genetic history of the animals in the breeding programme.  Ideally, only animals that would maximise the genetic diversity of the ex situ population would breed with one another. But what happens if the animals that we hope will breed don’t?

There are many factors that can affect the reproductive potential of animals.  These can include diet, group management, temperament and early life history.  For example, in wild golden-headed lion tamarins, where males as well as females provide offspring care, having multiple males in a group benefits offspring survival, growth and adult body weight.  Looking at how factors like this translate to the management of groups in zoos can therefore be useful for conservation breeding.

Silawasi macaque

Conservation breeding

In some cases, for example when animals are housed in family groups, zoos may want to delay or restrict reproduction, with a view to maximising the health of the population as a whole. Contraception is a method which is available to zoos to do this, and can be used to restrict breeding and manage certain medical conditions.

However, as animals have diverse physiologies and life histories, choosing the right contraceptive product for each species or context can be challenging. Although contraception is widely used in the zoo community, the distribution of knowledge is patchy.  

Veronica Cowl, Reproductive Biology Coordinator, explains:

EGZAC is really important because there are so many different ways to place animals on contraception and each individual has a completely different physiology to the next. We need to gather as much information as we can to identify trends so that we can make sure that the products and protocols we use are safe, effective and reversible because that’s important for conservation breeding programmes.

To this end, a centralised database was created by the AZA Reproductive Management Center (RMC) and EGZAC in an effort to collect information on the global use of contraception in ex situ wildlife populations. This database has over 40,000 records and collects information on products used, effects on health, impacts on behaviour, and future fertility to ensure that contraception practices are safe and effective.

Science team

EGZAC is an international collaboration between vets, curators, researchers, and zoo professionals that use their knowledge, experience, and the Contraception Database to identify gaps in knowledge to focus research in key areas of need. Information collected is also readily made available to ensure that decisions on using contraception are informed and evidence-based.

Veronica continues:

We have now also started to build a research aspect and that really comes from being able to work with the data and knowing what the needs of the zoo community are.

Exciting plans ahead! 

As EGZAC moves into its 10th year of supporting European zoo collections, we are increasing the support that we offer to the zoo community. Given the extensive knowledge on animal health and fertility within the group, EGZAC’s remit is widening to include reproductive management, in which we explore practical ways to promote reproductive success in ex situ populations. To facilitate this, the position of the Reproductive Biology Coordinator was established in a joint partnership between EAZA and Chester Zoo.

For more information on EGZAC please visit www.egzac.org or follow us on Twitter @EGZAC_1.  For more information on conservation breeding programmes please read the ZooQuaria Special Issue “EEP @ 30” (Spring 2016, Issue 93).