How do you reintroduce lions?

Wednesday 29th Nov 2023, 12.30pm

Lions are iconic species, but they are threatened with extinction. In Zambia, researchers and conservationists are working together to find ways of conserving these majestic animals and preventing them from becoming by-catch of poaching. In this new episode of the Big Questions podcast, we speak to Dr Egil Dröge from the Department of Biology to share the steps involved in bringing lions back to a national park in Zambia. Careful selection of a few young female lions which are genetically similar to those lost from the national park, and collaboration with local communities could pave the way for lions to return to the area over the next decade.

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Emily Elias: I don’t want to throw the word iconic around easily, but I would say that lions kind of fit into that iconic species status. Yet they are threatened with extinction, and working on conservation projects to bring them back into the wild, it can be tricky.

On this episode of the Oxford Sparks Big Questions podcast, we’re focusing on Zambia, and we’re asking, how do you reintroduce lions?

Hello, I’m Emily Elias, and this is a show where we seek out the brightest minds at the University of Oxford and we ask them the big questions. And for this one, we have found a researcher who is hoping that lions are going to make a comeback.

Egil Dröge: So I’m Egil Dröge. I’m the lead tutor in a postgraduate diploma in international wildlife conservation. And I’m also working alongside the Zambian

Carnivore program and Frankfurt Zoological Society in Zambia, where Frankfurt Zoological Society is restoring this national park. And I’ve been involved in the monitoring of this restoration and since 2017 in a project which should ultimately lead to reintroductions of lions in that national park.

Emily: Okay, so we’re looking at reintroducing lions. I mean, where did they go? What happened to them in the first place?

Egil: It’s a good question. so back in 2017, we tried to establish if the lions were really gone or if they were still present at very low numbers, because the last sighting of lions was actually a female with cubs was only a few years before that, in 2014 or 2015. So we had to establish, are they gone? And then to establish as why they were gone, is it lack of prey? Was it targeted poaching or was it poaching from bycatch or disease? So, that’s what we tried to work on, and it seemed that it was by catch from poaching. So poachers trying to catch other animals for food, would also catch lions sometimes.

Emily: Okay, so you figured out why they weren’t there. I mean, you’re looking at reintroducing them, how do you know which lion is the right lion to reintroduce?

Egil: Well, you try to find the lions who would be best suitable. So, in our case, we want to reintroduce these lions slowly. We don’t want to throw in a whole bunch of lions at once. So our aim is to reintroduce young adult females so they’re in the prime or at the start of the prime of their life so they should have an easy life, finding prey, catching prey. So they should have the best chance of survival in a new area where we bring them to.

Emily: And where do you get the lions from?

Egil: So these lions come from within Zambia. Zambia has several large lion populations, most notably in Kafui National Park and another one in the Luangwa Valley. So these are large lion populations and they’ve done genetic studies where they found that these two different populations, Kafui and Luangwa, actually belong to different sections in the larger lion population in Africa. So we aim to get lions from the Luangwa Valley because they were closest to Nasumbu National Park, where this is too, and they would have belonged to the same genetic group of lions.

Emily: Is that really important to make sure that you’re bringing in the right genetically friendly lions to that area?

Egil: It’s the best option. So if these wouldn’t be available, these genetic lions which were genetically close to what was originally there, then yes, maybe we would have chosen lions which were less genetically related. But within the larger landscape, there might be a chance there are still some lions available or present. And also nearby there are other lion populations in Tanzania. So if in the future there would be exchange, it would be best to try to mess as little as possible with the genetics to let the normal evolutionary processes take place.

Emily: How big is the population that we’re talking about in Zambia? How has it been decimated?

Egil: The total lion population in Zambia, that’s hard to estimate. Lions occur at low densities in Zambia. It’s maybe around five lions per 100 km². But overall, they estimate the Kafui lion populations in the hundreds, maybe between 200 and 400, and the Luangwa lion populations somewhere between 500 and 1000. So the Luangwa population is a quite large population.

Emily: And so then how many lions are you talking about moving around and reintroducing in?

Egil: Initially, we’re hoping on just a few females, two or three females. And that’s just to see how well they do. So we don’t want to take too many lines away from the source population, and then we first want to see, are they doing well before we start bringing over more lions. Obviously we have to bring in males as well if we want them to breed. And we don’t want a new population to start with too few lions because then they might suffer from inbreeding where brothers and sisters start breeding, or mothers and sons, which we don’t want. But initially, just a few lionesses to see is everything – the numbers of the prey numbers, the poaching levels. Have we removed all the old snares which poachers set on the landscape? Is that all OK?. And once these lionesses prove that things are all right, we’ll add some more. And over time, we’ll probably bring somewhere between 10 and maybe even up to 20 lions. But that might be over a time span of more than ten years.

Emily: How do you monitor these things? Like, do you have little lion babysitters that are checking up on them?

Egil: Lion babysitters? Well, there will be a team, dedicated to monitor these lions. So we fit them with radio collars around their necks. And these radio colours these days are quite sophisticated. They offer us several ways to monitor these lions.

First off, these radio collars have a GPS unit which takes a GPS locations of these lions every 1 hour, 2 hours, which we can actually, we can program that remotely. And then these collars send the GPS locations through satellites to a server. So we can just watch on a phone, on an app, where the lions are and so we can see did the lions move? And like I said we can program these remotely. So the first few weeks we will probably want updates more frequently than later on.

The second way we can monitor them is directly, visually. So these collars also have a VHF, a very high frequency unit, which sends out a beep. And that’s just we can pick up those beeps with antenna and a radio receiver, which we can tune into the specific frequency of the radio collar. And with that, we can pick up the signal when we’re on the ground, from up to 2 to 3 km. But when we fly in a little airplane, fixed with these antennas as well, you can pick up the signal from over 10km. The park has a dedicated airplane to monitor the park because the park itself is several thousand square kilometres. The wider landscape is over 10,000 km². So it’s a big area and they fly every week, they fly with the plane over the park to look for signs of poaching. Where are the elephants? Is there a fire? And they can also track collared animals. So the lions, elephants, buffaloes are collared which directs on the ground movements of the anti-poaching personnel. So that’s several ways we can monitor these lions to see if they’re healthy, see if they do what lions do.

Emily: I mean it sounds like a lot of moving parts going on. I mean how do you actually know if it’s going well? And what you’ve set out to do of reintroducing the lions is doing what it should do so that you can bring in more.

Egil: Yeah so how do we know if it’s doing well? So initially we would monitor them very closely. We would aim to see them every few days on the ground visually, physically. Later on that will probably be turned down to a bit more. And every time you see them you want to check, do they look healthy, do they have injuries, have they eaten? One way, which also offers these GPS collars, you can look for clusters of points. So if you see these lions have spent a prolonged time at a single spot, you can go and look, investigate those spots and what happened there and oftentimes you can see, did they make a kill, did they eat? So that can offer insights into, do these lions actually manage to catch prey? Which is an important thing to do for the lions because that’s what keeps them going.

Emily: But why is it important in the first place to go to all of this trouble to reintroduce these lions?

Egil: Well, yes, we try to keep ecosystems intact. Intact ecosystems, they’re very valuable for people. They provide clear water, they provide food, also for people. And in this system, that’s also the case. Like, it’s bordering Lake Tanganika, there’s a lot of people relying on fisheries.

And lions can be used in several ways for conservation management. First off, they’re an indicator species, which means that certain species, if they do well, it’s an indication that the whole system does well. So it’s good to monitor indicator species, and you need to have those indicator species to do that.

Secondly, they can be a keystone species. So, they’re relatively more important to the ecosystem than other species. And again for large carnivores, top predators often act as keystone species.

And then a third one is lions are flagship species. Everybody knows lions, they attract attention. And with attention, you can draw the attention to the park, attract more tourists, generate more income for the park, for example. So, for those three things, there are important species. And in this park, lions went quite recently extinct.

The other thing is, so you want to keep the biodiversity in the park intact and the people living around the park, for one of these chiefs, his symbol is actually a lion. So it’s quite sad that they’ve possibly lost the symbol of the chief. And so we’ve been working with these communities as well to reintroduce them. And actually, most of the community members believe the lions are still around. And if lions come back and do well, that would be the proof in the pudding that the ecosystem is doing well again.

Emily: This podcast was brought to you by Oxford Sparks from the University of Oxford with music by John Lyons, and a special thanks to Dr Egil Dröge.

Tell us what you think about this podcast. You can find us on social media, we are @OxfordSparks. Whatever that platform might be called these days, we are there. Or you can check us out. We have a website

I’m Emily Elias. Bye for now.