The Cilla Black of tigers

Matchmaking tigers is a tricky genetic job.
14 November 2017

Interview with 

Jo Cook, ZSL London Zoo


Tiger and cubs


Once Kat Arney escaped from the delightfully relaxing bird pavilion, she went off to the other side of London Zoo in search of larger prey - or rather, predators. She chatted with Jo Cook, from ZSL London Zoo, about tiger dating and what population management actually means for a species like the Sumatran tiger.

Jo - I'm Jo Cook. I'm a Conservation Breeding Specialist for Zoological Society of London and we’re currently in our Sumatran tiger habitat at London Zoo and that is one of the programmes I manage for the European region.

Kat - So you're basically the Cilla Black of tigers?

Jo - That’s not been said before but yes, I guess I am.

Kat - We’re here in the tiger enclosure, your lovely tiger territory here. We can see a tiger up there just relaxing. Presumably, that tiger is in your breeding programme.

Jo - That’s right, yeah. We’ve got a pair of adult tigers here, Jae Jae and Melati, and this is their second litter that they’ve had as part of the breeding programme. In a few months’ time, the youngsters will be going off to other zoos to continue the programme and make sure that their genes are captured for the future.

Kat - Unfortunately at this point the tiger enclosure was over-run by an invasive species - noisy small children - so Jo and I headed up to her office to chat about tiger dating in more detail, and what population management actually means for a species like the Sumatran tiger.

Jo - So for us, it’s maintaining a captive population that is genetically and behaviourally diverse so that we can support their wild counterparts and that can be in terms of raising awareness and funds for in situ conservation but also, maintaining a lifeboat population if you like, should reintroduction be necessary in the future.

Kat - So, if all the wild population is completely wiped out, your like, “Hang on! We’ve got some in the zoo. Let’s try and put them back.”

Jo - Obviously, we hope that will never happen but yes, that’s one of the reasons for maintaining captive populations.

Kat - And with something like the Sumatran tigers that are so endangered that there are so few of them left, how do you go about managing that population, working out how to keep them genetically diverse and keep that population sustainable?

Jo - It can be quite difficult. The one thing we rely on is actually knowing how each tiger is related to every other tiger within the population, because we do want to maximise that genetic diversity.

It’s very important that we have good clean data, and we know how all the tigers are related. And by analysing that information, we can then decide which tigers should be breeding together and which pairing we need to create to make that happen.

Kat - How do you work out the genetics of an individual tiger? Do you need to take a DNA sample? How do you do that apart from “very, very carefully”?

Jo - For some populations that definitely is needed. But for the tigers, we’re very lucky and that has been a very long running historical stud book and we can actually trace each one of our captive tigers right back to its wild founders. So we can do it through pedigree analysis rather than DNA analysis.

Kat - What would you mean by a stud book? What is that?

Jo - It’s essentially a database which contains all the information of every tiger that’s been born within the captive population. And that does include recording data on animals obviously that have died, but also, those that were stillborn because that information is necessary for demographic analysis.

Every time an animal is born, we enter into a stud book along with its parents and where it’s born, etc. Throughout its life, we track its movements between different zoos and obviously, the last record will be its death.

Kat - What happens when another zoo wants you to play Cilla Black and says, “Oh, we’ve got this tiger…” How do you set up a tiger date?

Jo - It is very difficult because obviously, the other thing about tigers is, they're such amazingly beautiful animals and tiger cubs bring in a lot of revenue for zoos. Everyone pretty much wants to be breeding tigers and we do have to limit the number of recommendations we can give because there simply isn’t space to house all the potential tiger cubs there could be.

So, when a zoo does approach us, we have to see whether they have important animals and whether they should be given priority for breeding, and if not, we have to try and shift things around if you like and move tigers to the right places to meet up with the right mate. It is very complicated and it’s been likened to moving house a thousand times over with all the added stress but yeah, we get there.

Kat - And what happens if you go through all these process and the tigers don’t hit it off or they don’t make cubs together?

Jo - It can be highly frustrating when that happens and occasionally, there are just incidences where two animals just aren't compatible or you may find that a pair isn’t compatible in one place but if you move them to a different zoo, actually for some reason they're quite happy together. So, there's lots of other variables that affect the success and we just have to deal with those as they happen.

Kat - Focusing on the wonderful tigers that you have here, tell me a bit about them and their breeding history. You’ve had quite a lot of luck with them, haven't you?

Jo - Yeah. We have a breeding pair. The female is Melati and the male is Jae Jae. Jae Jae came to us from Akron in the United States and Melati from Perth in Australia. That was part of the global programme that we also manage here at ZSL. They currently have two cubs with them and they previously they had three cubs but those animals have already grown up and gone to their new homes to continue the programme.

Kat - So the cubs that have already headed out into the world, are they breeding yet? Have they got grandchildren out there?

Jo - Not just yet. They're still a little bit young for that but maybe in the next 2 or 3 years, then yes, there will be grandchildren from the London Zoo pair which will be great.

Kat - When Jae Jae and Melati did successfully raise their first cubs, how did you feel? Did you feel a bit sort of maternal or grandmotherly?

Jo - Yeah, absolutely! The majority of my time is spent in front of a computer. So to be actually able to go down to our enclosure and see the cubs that have been produced as part of a recommendation, it does bring at home to you and you think, “Yeah, that’s a good day!”

Kat - Given how successful Melati and Jae Jae have been with having cubs, are there plans for having more? I mean, if they're so good at it, why don’t you have loads and loads, and loads of cubs from them?

Jo - That would be lovely but unfortunately, we don’t want to have an influx of their genes within the population. So, it’s actually unlikely that they will have another breeding recommendation, certainly in the near future, and we might need to look at changing the pair we have here.

Kat - Oh my! You're going to split them up.

Jo - Possibly, but we will see, yes.


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