The (no) mating game
Published: 11th Mar 2018Paignton Zoo is open as usual - but behind the scenes, animal staff are busy juggling lions, tigers and giraffes...
Staff at Paignton Zoo are in the strange position of trying to prevent hundreds of animals from breeding. Where they might normally be delighted at the prospect of lion cubs or zebra foals, right now it’s a case of “No sex please, we’re under TB restrictions.”
A single case of TB at the Zoo last year led to the deaths of eleven antelope. The animal charity can’t move mammals in or out because of restrictions automatically imposed by the Animal and Plant Health Agency. Staff don’t want animals to breed if there isn’t the room to keep them properly.
When it comes to dealing with the consequences of TB, Paignton Zoo is better placed than most farmers and many other zoos. The Zoo has its own in-house vet team with three vets and two vet nurses based in a purpose-built Vet Centre. In charge is Ghislaine Sayers, Paignton Zoo’s Head of Veterinary Services. She has a plan - and it’s a huge plan, taking into account some 60 species, including primates and hoof stock.
Ghislaine: “Animal contraception is a relatively young science and presents us with many problems and worries. Some groups are single sex, which is one piece of good news. But we have many breeding groups here because that’s something we do – breed rare and special animals.
“In many cases we need to discuss contraception with the studbook coordinators or the European Endangered species Programme supervisors for the species. What we do here could have consequences for international breeding programmes.” The animals are the responsibility of Paignton Zoo but in many cases they’re playing an important role in the future of their species globally.
Ghislaine: “Contraception is a complicated subject. I find it fascinating, but it is also vitally important to large parts of our collection right now. We must prevent overcrowding but we must still be in a position to take part in breeding programmes when the restrictions are lifted. So we need temporary solutions.
“We can simply separate males and females during the breeding season if they are seasonal breeders, like maned wolves. We can also give contraception to both males and females; it comes in the form of tablets, injections, implants and IUD coils. Some of the injections act like a vaccine that kills off the animal’s own reproductive cells.”
Ghislaine is upfront about the risks associated with contraception. “It isn’t an exact science. The length of time the contraceptive works may vary between individuals. Animals could get pregnant if the contraceptive wears off earlier than anticipated.
“If animals are contracepted too young it may permanently sterilise them. Contraceptive implants can be lost - I’ve known them to be groomed out by primates!”
Contraception can sometimes change a male animal’s appearance - he may lose his mane, or experience muscle loss, for example. And contraceptives may change the way other animals interact with them, as they might not be perceived as either male or female. Finally, inserting a contraceptive implant may require a general anaesthetic, which is always something of a risk in itself.
Some types of contraceptive can cause uterine disease or predispose an animal to neoplasia (abnormal tissue growth), as they can in people. Ghislaine: “It’s a pretty new technology, so we are still collecting data on contraception in different animals and how it might affect them. And animals are individuals, so – like humans – some contraceptives suit some better than others.”
The Zoo has consulted extensively with the European Group on Zoo Animal Contraception, a Europe wide body that shares data, experiences and recommendations, as well as colleagues in EAZA, the European Association of Zoos and Aquaria. Meanwhile, the Zoo is working closely with the Animal and Plant Health Agency, the government agency that runs alongside DEFRA. Restrictions will only be lifted when APHA are satisfied that TB has been eliminated from the Zoo’s animals. Paignton Zoo Environmental Park is a registered charity.