Sea Turtle Stories – Episode 2

Minnie: To give the briefest of overviews, Dr Jeanne Mortimer has been working in the field of sea turtle conservation since the 70s, and has worked with turtles in over 20 countries across 6 continents. She has published over 200 papers and has been at the forefront of sea turtle conservation, particularly in the Seychelles – a place she has called home for the best part of three decades now, and where she founded the Turtle Action Group Seychelles or TAGs – an organisation that brings together sea turtle researchers for communication and collaboration. In fact, she’s popularly known as Madame Torti in Seychelles – tori meaning turtle in French.

We’re very fortunate to have her here with us today and to get a chance to pick her brain about all things sea turtles with a special focus on sea turtle nesting.

So welcome Dr Jeanne, thank you for joining us.

Dr Jeanne: Well, thank you for your interest, Minnie. It’s so nice to meet you.

Minnie: It’s so nice to meet you as well.

Minnie: So we’ve got a huge amount of incredible stuff that we could talk about, but I think to try and sort of initially start us off, I would love to know, because you’ve been involved in so many different fields of sea turtle conservation, and I’d love to know what you would say is one of the most interesting or the one that you enjoy the most across your experience so far.

Jeanne: Well, you know, one reason I was interested in studying sea turtles is, you know, sea turtles are both marine and a bit terrestrial since they have to come ashore. So you get to look at a lot of different things.

And also, I’m kind of like a little bit of an anthropologist at heart. And sea turtles tend to be very important to people economically where they occur. And so if you want to work with sea turtle conservation, you really also need to be able to work with people and try to understand them and their relationship to turtles.

And so, you know, to me, combining these different fields is really, you know, has been really interesting over the years. And I don’t know exactly which I would enjoy most. It’s just, you know, to me, it’s a very holistic view of something.

You know, people might say, oh, you’re just working with sea turtles, but sea turtles are really a very broad thing. And because they inhabit so many different ecosystems, you know, they serve as a really good flagship species for the various ecosystems. And they can attract conservation attention to the ecosystems, in addition to attracting attention to themselves.

Minnie: It certainly is really nice. I think a lot of people do forget the human aspect of working with turtles.

Dr Jeanne: Yeah, it tends to work both ways. It’s not always positive for the turtles, but you can’t just discount people. You have to try to work with them and solve problems with people.

Minnie: Absolutely. And I suppose to that end, you’ve obviously worked on a lot of really interesting projects, sort of helping to standardise monitoring projects, but also set up quite a few. But there is one in the Amirante Island that I think our listeners would be really interested in because it kind of touches a lot upon what you just said regarding sort of working with people.

Dr Jeanne: Yes, that was in D’Arros, St. Joseph. You know, if you look at Seychelles in the outer islands, for a long time, the only outer island sea turtle monitoring project that was functioning was at Aldabra. And of course, Aldabra is very exciting.
But there’s lots of territory and lots of islands in the outer islands. And it wasn’t until 2004 that we set up a long-term monitoring project at D’Arros. And we set that up using local workers. And just the guys working on the island, I kind of enlisted them, trained them to understand what kind of data to collect. And they got really excited about it. It was great to see some of these guys who had previously been fishermen or even were still fishermen and had a history of killing turtles.

And as they got to know them more and more, they started looking at them in a different way. And what’s always been really fun is to try to get people to look at the turtles in a different light than how they had looked at them before. And when they realise how complicated their life history is and just how interesting these animals are, I’ve always been really happy to see how people respond.

And I love working with fishermen because they have a sense about the animals. And they take good data because they understand the animals.

Minnie: Yeah. Many people have said no one can find eggs, you know, perhaps with the level of skill and sort of intuition. Perhaps someone who formerly used to take them to eat but now sort of does it to monitor and assess.

Dr Jeanne: Yeah, that’s right. It’s like, you know, when we’re doing beach monitoring, you know, you want people to say, look at the track, the turtle track and say, did this turtle lay eggs or not?

And the ex-poachers, I can trust their data because they’ve watched turtles, and they had a pretty good sense about, you know, what the track really meant, did this turtle lay eggs or did it just dig around, you know? So it’s kind of interesting. Yeah, they have a lot of very, very useful lived experience, very much learning on the job on that one. And one thing I think, that, was an important concept to get across.

I found this in Seychelles, I found this working in Malaysia, just about anywhere, people have a tendency to look at the turtle resource and they think, oh, these things must take about two or three years to become adult, like a pig would or a chicken – the domestic animals they’re used to. And so, you know, look how many there are. We can certainly kill lots of them because if we have a lot of pigs, we can kill a lot of pigs and get more pigs very quickly. And turtles must be the same. And when people start to realise, well, actually turtles are more complicated – from the time a turtle hatches from its egg until the time it first comes back to lay eggs. For green turtles and hawksbills, you really need like, you know, at least 25 years, sometimes as much as 40 years or sometimes even more for the animal to reach adulthood.

And so when you start to look at it like that, it’s like, oh okay, so it’s not the same as a pig. It’s a very different sort of thing. And the turtles that you’re looking at on the beach this year may have hatched out of their eggs 35 years ago.

So what happened 35 years ago is going to determine what kind of population you have now. And what you do now is going to determine what kind of population you have 35 years from now.

Minnie: Yeah, it’s very long term.

Dr Jeanne: Yeah, it’s a hard concept to get across. I developed different diagrams to show it, which seemed to be pretty successful. But, it’s a completely different way of looking at things. Because people just assume, oh, we’ve always had turtles, we’ll always have turtles and we can do whatever we want with them. And it’s not true.

Minnie: Reptiles, I think in general, do go a little bit, you know, under the radar with a lot of people. People sort of don’t think reptiles have much going on. They don’t have any facial muscles. They can’t really emote in the ways that we identify. So just understand the sheer amount of time these guys have taken to get to that stage and the work that they’ve put in to get to that point is actually really quite remarkable.

Dr Jeanne: That’s right. And so once you have a female on the nesting beach, you’ve got a very valuable animal. It has taken ages to get to that point.

Minnie: Yeah. And actually, that’s a really good segway into nesting. This is a really important life stage in a particularly female sea turtle’s life.But why is it actually so important to study nesting turtles and what does it offer to the wider field of sea turtle conservation?

Dr Jeanne: Yeah, I think it’s very important to understand nesting turtles because, first of all, you know, the long time that they’ve taken to reach adulthood, finally they’re doing what they’re supposed to do to maintain the species.

And if you don’t let them do that, you won’t have more turtles. So it’s an extremely important stage in their life cycle. But it’s also an extremely vulnerable stage in their life cycle because they have to drag themselves out of the water. They’re not really comfortable coming out of the water, and for good reason, because once they’re on land, they tend to be pretty helpless against land predators, which include humans. And so, you know, it’s very important to understand their behaviour and also understand, you know, their habitat, where is it that they’re nesting and make sure that people understand what are their habitat needs.

You know, you may love nesting turtles, but that’s not a good reason to put up a resort with lots of lights right next to the beach so that people can come and view them, because you won’t have turtles moving forward. What’s really important really is to identify what are the critical nesting areas around the world and then make sure that you take the precautions needed to protect those habitats.

And obviously, like in a place like Seychelles, you can’t protect every inch of beach because people need to be able to use the beaches. But I think it’s important to identify what are the most important beaches and try to establish protections. And often the protections don’t have to be painful for people, you know, just use a bit of common sense, keep lights off, don’t have people running around on the beach when the turtles are nesting.
This is a problem in Seychelles in the sense that, you know, we have two species. We have green turtles and we have hawksbills. The green turtles nest at night. And so they’re like normal turtles in most parts of the world. And it’s easier to have tourism with green turtles because all you have to do is make sure that at night your beaches are dark and at night most people are asleep. So they’ve gone to bed and the turtles are out nesting.

Now, in Seychelles, for some reason, and we do not really understand why, the hawksbills nest in the daytime. And they do this in, I found that they do this in the Western Indian Ocean in general. But Seychelles has most of the nesting left in the Western Indian Ocean. So this would include, you know, Chagos, the Mascarene Islands, Seychelles and the East African coast.

If you go up into the Red Sea area, the Persian Gulf, they also tend to nest at night, but they kind of do half-half. But if you cross the ocean over to Western Australia, they’re night time nesters.

Minnie: Yeah.

Dr Jeanne: Getting back to Seychelles, when they are nesting in the daytime, if people are out on the beach, as they tend to be, the turtles are terrified and they’ll go back into the sea. And so, you know, in that sense, tourism and turtles are not that compatible unless it’s really well controlled.

Minnie: Yeah. It’s really interesting to me. Like you say, Seychelles carries now one of the most important hawksbill nesting sites. So we still don’t really understand why they’re up in the day? That’s something we’re still not really sure of?

Dr Jeanne: No, it’s really interesting. It’s an interesting issue. If you look at the turtles that are, you know, like in the Western Indian Ocean, they’re all kind of genetically more or less related to each other and different from, say, Western Australia turtles – hawksbills.

But, you know, it could just be an accident or it could be a good reason. Some of the ideas people have had is, oh, maybe it’s sharks. You know, maybe there’s the sharks are more dangerous at night or, you know, but that wouldn’t explain why green turtles don’t mind coming up at night. So it could just be an accident.

But what we do see is when the hawksbills do come up in the daytime, they go straight through the bushes and they, you know, you rarely find them nesting on the open beach. It’s too hot for them and it’ll be hot for their eggs too.

But it may just be an accident. It may just be like an accident of evolution. You know, every behaviour doesn’t have to have a purpose. If it’s not deleterious, then it can stay.

Minnie: That’s true. Yeah. If it doesn’t actively, you know, decimate the population in some way, I guess it can just hang about. Very interesting. And that’s something I would love to see.

But I was going to say, one of the big problems for most daytime nesters would be the fact that it’s so hot, so I guess that’s how they mitigate that – by just legging it to a bush.

Dr Jeanne: And hawksbills can go pretty fast if they want, you know. I mean, you do occasionally find a hawksbill nesting in the open sand, in the open sun. But yeah, but that’s pretty rare. They mostly go right under the bushes and stay there.

Minnie: Do we assume that that’s like a new mother or do we assume that they’ve just made a mistake?

Dr Jeanne: It’s hard to say. I think that’s something that could be the topic of a study. Who are these females who are stopping in the middle of the beach?

Minnie: I would say that was one of the things we would say jokingly amongst the team on the island that I was on, you know, if there was a green who came up and then just made a complete hash of it. Terrible, terrible sort of location. Terribly dug chamber. We’re just like, maybe she’s new, you know, maybe she’s new to this.

Dr Jeanne: And what’s kind of interesting is that there doesn’t seem to be a lot of reproductive senescence in female sea turtles. They tend to lay more eggs as they get older and bigger. And they don’t grow much once they reach adulthood, but they do continue to grow a bit. And bigger turtles tend to lay more eggs. And it seems like the older turtles, the ones who are coming back multiple times, tend to lay more egg clutches. And so they get better with age.

Minnie: They get better with age.

Dr Jeanne: Yeah. So that’s good. And we don’t know really whether, you know, what happens to the old females. Do they drop dead when they’re no longer nesting? Or do they go to the rocking chairs in the feeding ground somewhere far away and rest, you know, until the time comes to die? But meanwhile, the ones that we see, you know, the ones that are coming over the longest period are doing better.

Minnie: Amazing. Do you have data regarding the Seychelles about some of the sort of nesting durations of some of the females? How long has the longest girl been coming back?

Dr Jeanne: Yeah, I don’t have the latest record, but certainly like 35 years where some females will come back that long. It’s amazing. But it does seem like based on our data, that most of them stop, we stop seeing them after a shorter period of time. But it’s not a real short period. You know, 20 years is not a big deal for turtles to be coming back. And, 10 years certainly is nothing for them.

So if you think about it too, you know, humans become reproductively mature, if not mentally mature, at about 12 or 13. You know, they shouldn’t be reproducing, but they can. Whereas a turtle is, you know, takes a much longer time to become sexually mature than a human.

And then a turtle will, you know, will remain sexually mature, probably longer than a human would. But some go, well, they’re in their 60s and still laying lots of eggs, whereas humans by that time usually have stopped producing offspring. And that’s why it’s just so important that, you know, to respect these breeding animals, because they really, you know, they’ve survived so much.

I mean, you know, it isn’t just that turtles are dying when they’re hatchlings. So people always think, oh, they all die before they get to the sea. You know, that’s not true.
You know, they do have a lot of problems on the nesting beach, especially with things like crabs. But once they get into the water, it’s quite interesting. I mean, I’ve followed hatchlings out to sea, both in the daytime and at night.

And I found that once they get into about 10 metres of water, the predators that would have been coming up before to eat them tend to look up and they see the turtle at the surface of the water and just say, uh, I’m going to stay down here. Because it’s dangerous for a fish to come up through the water column to get to the surface. They’re exposing themselves. So once the turtle gets into fairly deep water, the level of predation goes way down.

But they have a lot of time to grow over the next, you know two, three decades. And during that time, an awful lot of things can go wrong. You know, they can get eaten by bigger fish. They can get into nasty currents that are unhealthy for them, maybe too cold or not enough food. They can get sick. A lot of opportunity to get sick over 30 years. You know, it is tough for them. And so once they do become adults, it’s so important to try to do your best to not kill them and let them reproduce.

Minnie: Yeah, looking at watching a female, you know, haul herself onto the water, you just think you are putting in the absolute most amount of effort.
You know, she is trying the absolute hardest. They really are giving it their all. And it’s just incredible to see.

Dr Jeanne: Yeah, and I’ve seen turtles come up with horrible wounds on them, you know, missing flippers, recent bites from sharks.

I did my doctoral work on Ascension Island in the South Atlantic, and there’s some really heavy seas there and lots of rocks. We had turtles coming ashore that had obviously been slammed on the rocks.You could take a torch and look inside them and see their organs inside their body. But they’re still coming up to nest.

They’re still going. Turtles missing a flipper, you know, and they’re trying to dig a hole with one flipper. I’ve seen the turtle trying to dig a hole with no flippers.

Minnie: Yeah, the drive is incredible, the instinct to do it.

Dr Jeanne: Yeah. So it’s pretty impressive.

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Minnie: I think regarding nesting, it’d be good to talk about the fact that, we have recorded pretty significant distances between a female sea turtle’s nesting grounds and their foraging grounds.

So they tend to only nest, it depends on the species, but every few years generally, and then they’ll have a big gap of, yeah, two, three years where they recoup, they get their energy back, they eat a lot, and then they’ll do it again. But they usually travel pretty significant distances to do that. I understand from some of your research that we’ve found that in the Seychelles, the hawksbills are actually pretty local. Is that right?

Dr Jeanne: Yes, it’s quite interesting. It’s, you know, this was helpful, to find this out. It was very helpful in terms of conservation and trying to, you know, make people understand that they have a responsibility to protect these animals. Because when I first came to Seychelles, people would say, oh, you know, the turtles go away and they go to other countries and people are killing them. And why should we, you know, deprive ourselves of turtle meat when other people are eating our turtles?

And, but the thing is, you know, first of all, if a turtle is coming ashore, you know, at the nesting grounds, it’s the most vulnerable place. So whoever owns the nesting grounds, whether it’s in Seychelles or any other country, they are responsible. They really have the highest responsibility for taking care of the animals because that is their most vulnerable time in life.

And when turtles do travel to other places, they’re out at sea. And so if someone’s going to kill them, it’s harder to kill them then, than it is when they walk up on the beach and they’re helpless, you know. So they are less vulnerable once they’re farther away at the feeding area.

But I was, I was interested in the fact that when we were tagging our green turtles, like, especially at Aldabra, we were getting the occasional turtle captured in East Africa, Madagascar, you know, some of these places far away. And yet the protection at the nesting grounds enabled the population to increase. So even though we knew that some turtles were being killed farther away, protection at the nesting ground was causing the population to increase. Although up until the time of protection, it was massively decreased.

In the late 1960s, the population of green turtles at Aldabra was just a fraction of what it had been in the early 1900s, you know, so they definitely declined. Whereas, now with hawksbills, I was interested in the fact that we had tagged lots of hawksbills in the inner islands of Seychelles, but we were not getting tag returns from overseas, even though we were getting green turtle tag returns from overseas. So I was thinking, okay, maybe they are staying, you know, in areas not near where people are hunting turtles, possibly staying in Seychelles.

But the only way to really prove that was to do some satellite tracking. And so when we did satellite tracking of the turtles, we found that turtles tagged at Cousine Island, which is right in the, kind of the centre of the inner islands, they stayed on the Seychelles bank. So they stayed in Seychelles waters. And so this was a very good message to be able to tell people, look, these are your turtles, you are responsible, don’t feel that, you can just kill them on the nesting beach because they’re going to go somewhere else because they’re not, you know, they’re staying mostly in your waters. Now, more satellite tagging over time has shown us that some of the animals are actually going farther away.

Some get down into the Mascarenes, some go down to Madagascar, but those are really only a very small percentage of the turtles. Most of them are still staying within Seychelles waters. So they are Seychelles turtles, but they’re Seychelles turtles as adults. As hatchlings, when the hatchlings get into the sea, they probably travel all over the Western Indian Ocean because they get caught in currents and they don’t have much control of themselves.

Gradually they work themselves, you know, as I think as a juvenile, they’ll be feeding at islands that are outside of Seychelles often, but then as time goes on, they move closer and closer to their original place of nesting and tend to stay, you know, stay nearby. And in Chagos Islands also, by satellite tagging hawksbills, we found the same thing. They tend to stay in the Chagos archipelago, whereas the green turtles are going far away, we’ve got green turtles travelling, you know, 4,000 kilometres to Somalia or along the East African coast, which the hawksbills tend not to do.

Minnie: That’s really so interesting. Does that by any chance at all make their inter-nesting interval shorter? Because usually the sheer distance that some of these turtles, are travelling controls how much they’re going to nest because they’re travelling, yeah, 4,000 kilometres to reach their nesting ground. So does it mean that the hawksbills of the Seychelles nest more frequently or not really?

Dr Jeanne: Yes, I do think it does. I think our green turtles tend to nest at longer intervals, sometimes three, four, five, six years between nestings. Whereas the hawksbills, the hawksbills in the inner islands, this is kind of interesting. The hawksbills in the inner islands tend to come back after two or three years, which is fairly short for sea turtles.
And I think that’s because they’re not really leaving, most of them are not really leaving the Seychelles plateau. And so their life is a little bit easier.

But what’s been kind of interesting, we started satellite tracking hawksbills from the outer islands of Seychelles and the Amirantes group at D’Arros. And those turtles, I was really, you know, really anxious to find out, do they stay in the Amirantes? You know, just like inner island turtles stay on the Mahe plateau, do Amirantes turtles stay on the Amirantes bank? Or do they go somewhere else? And it turns out that the hawksbills in the outer islands of Seychelles tend to go to the Seychelles plateau, to the Mahe plateau. So they travel farther. And our tagging data, our preliminary tagging data is suggesting that the inter-nesting interval for those, the remigration interval for those turtles, the time between nesting seasons, tends to be maybe a bit longer, like more like four years, as opposed to two or three years.

So, and if you watch these things when they’re migrating, you can track their movements and you think, oh my gosh, you know, these things, we’ve had turtles that kind of get lost going to the Mahe plateau, they get to the plateau, they don’t like it, they come back to their island where they were nesting, go back again. You know, I mean, it’s crazy. Whereas the ones that are starting from the inner islands on the plateau tend to have an easy time finding their feeding area at the plateau.

So they use different kind of cues, I think, when they’re migrating.

Minnie: Nesting sea turtles do seem to be quite picky, I suppose, in deciding their nesting kind of grounds and the, I mean, they can sense the density of the sand and everything, can’t they? They can establish exactly like where they want to nest based on all the things we probably can’t even figure out ourselves.

Dr Jeanne: Like you’re watching them and, you know, you’re waiting for them to lay their eggs. And it’s kind of like, well, what’s wrong with that hole? Well what’s wrong with that hole? It looked good to me. But they’ll kind of move on to another one until it feels quite right to them. Until it’s perfect.

Minnie: And considering the effort that they take to be digging these holes, I mean, they’re digging them just with their back flippers, which I think is the most incredible thing. And suddenly, yeah, after spending all of that time doing that, they’ll trap along to a completely different part of the beach. There’s no reason that we can figure it out.

Dr Jeanne: Yeah. People have said, oh, maybe they’re just providing false holes to, you know, confuse predators or something. But I don’t think that’s the case at all.
Because one site I’ve worked a lot at in Costa Rica is at Tortuguero, where there’s a lot of rain and very, very fine sand. So digging a hole there is really easy. And those green turtles tend to come up, dig one hole, lay their eggs and go back. It’s very rare that they will be messing around on the beach for very long. Whereas the green turtles that are nesting on the calcium carbonate, white, beautiful sand beaches that have round, relatively dry sand, you know, round particles, fairly biggish particles.

Minnie: Yeah.

Dr Jeanne: They have a hard time. Cause even for people, you know, when you dig a hole in the Tortuguero beach, the sand is very fine and it tends to be volcanic. So it has sharp edges. So it doesn’t have these round, smooth grains that tend to collapse easily.

And it’s very easy. You just, you can just dig a hole and make a nest for yourself, you know. Making up nests in these coralline sands is really hard work. Even like checking hatching success. You know, it’s a real pain because they keep collapsing too.

Minnie: Do you, how long on average do the sea turtles spend nesting? What is their general kind of nesting time?

Dr Jeanne: I think the hawksbills are a little quicker than the greens. And that may be partly because they’re, they’re tending to dig shallower holes deep in the vegetation. So they tend to be moist holes, you know, with vegetation, the sand is a little bit moister. So they might have a little bit easier time digging. But you know, they tend to be up on the beach, maybe an hour or two, sometimes a little bit more. Whereas green turtles on these, you know, they’ll be digging on the coralline sands and sometimes, you know, tend to be more in the open there. They can dig under the vegetation, but they often dig on the open, open beach.
And they’re digging deeper. You know, whereas a hawksbill might dig down to about 50 centimetres or less. The green turtle will go down to 80 centimetres.

And it depends on how much rain an area gets. If it’s a high rainfall area, they’ll spend less time. But when I was doing my doctoral work on Ascension Island, which only gets like five centimetres of rainfall a year on this coralline, I had females come up and dig, my record was 14 nest holes. And she went back, she went back because she wasn’t happy. And they can come up several days in a row before they finally are successful.

Minnie: 14.

De Jeanne: Yeah. Now 14 is very unusual, but that’s just to give you an idea. Imagine how much work that is.

Minnie: Yeah. I mean, I did see one turtle who came to nest at the Maldives and she was there for seven hours, just wandering around, trying to find somewhere she liked, dug, did a body pit, left, dug another hole, left and just, yeah, and then sat down for two hours. Just exhausting.

Dr Jeanne: Yeah.

Minnie: It’s just an incredible amount of effort that they do have to take to do that. And they do that, obviously, I suppose it depends on the species, but usually about, well, I think greens are up to sort of eight times potentially in a season.

Dr Jeanne: We’re finding out more and more now that greens can come up a dozen times. So whereas hawksbills, at least in Seychelles, our hawksbills tend to max out at about six to seven, eight clutches. And so the average is more like three or four per female.
But we’re finding for green turtles, the average is probably more like six, and they can go up to 12 clutches in one season. And that would probably be the older females.

Minnie: Yeah, the experienced girl.

Dr Jeanne: Yeah, but this is another point that’s really important to try to get across to people, because once your turtle population starts to increase, as it has been doing in Seychelles, people see lots of tracks on the beach, and they say, wow, look at all those tracks, we can start killing turtles again. I see a hundred tracks, must be a hundred turtles.

But actually, you have to consider that each time a turtle lays a clutch of eggs, she
probably, even for hawksbills, can come up an average of two times, and for green turtles, more. And then each female lays X number of egg clutches. So let’s say for hawksbills, if you say the average is about two times to come up before they actually lay a clutch of eggs, and they lay an average of four clutches per season, sometimes more, that means one turtle equals eight tracks. Eight tracks does not equal eight turtles, and that can be a hard thing to get across to people. No, it’s not quite as good as it looks. And green turtles are even more so, because a green turtle may come up an average of three times, and lay an average of six, seven, or more clutches. So three times six or seven is 21 tracks. And so 21 tracks does not equal 21 turtles. And this is something that’s really a hard concept for people to absorb, but they need to.

Minnie: So between each nest, how long do the turtles wait, I guess? What’s the average?

Dr Jeanne: For most species, it’s about two weeks. But one thing that’s kind of interesting, we found that during the cooler part of the year, it tends to be a little bit longer. And so they tend to lay their egg clutches closer together during the warmer periods, and that’s because their metabolism is higher, because they’re cold-blooded animals.

So that means in between egg clutches, in between coming up to lay a clutch of eggs, they’re sitting offshore, preparing the next clutch of eggs. And so if you were to kill a turtle right after she laid a clutch of eggs, you will find no shelled eggs inside that turtle, because she needs to go back, lie down on the ocean bottom, and wait two weeks while she runs the next set of yolks down her oviduct. And during that time, the shells are put on, and then she’ll have shelled eggs.

So she arrives with ovaries full of yolks, but not shells. And so you can see how in warmer water, they’re going to produce the shelled eggs quicker than in colder water, because their metabolism is higher.

Minnie: It’s really interesting. I think it’s interesting for people to know that generally, we understand that turtles do not eat during their nesting period. So they will spend this whole number of months that they are doing all of this, sitting around waiting for their oviducts to kick in. They’re not eating at all.

Dr Jeanne: That’s right. And we just put a paper out a couple of years ago, where I was looking at, when I was first in Seychelles, they were killing turtles legally, and I was collecting gut contents. And I collected all these gut contents from males and female turtles that were being killed. And then I got a student, Holly Stokes from Swansea University, to analyse these gut samples. And fortunately, I had preserved them quite well. And she was still able to see what was inside.

But we got definitive proofs that at the nesting area, you had both males and females. We could see them mating at the time. But the males’ guts were full of food, absolutely chock-a-block full of food. And the females were completely empty, in most cases, or filled with weird stuff, like little twigs, and maybe calcium carbonate chunks of sand. And I think what happens is the females, first, they need the room. They can’t be filling up their gut, their internal cavities with food.

Because they start out with like 1,000 eggs or more, and then each clutch has to be shelled. And so each clutch takes up more space as it’s being shelled, and the albumin is put on, and the white of the egg. And so they really need to make sure that they’ve got lots of fat stored up from previous, from their feeding time. But now is the time to focus on the work. Whereas the males are having a wonderful time. They are mating and feeding and mating and feeding

Minnie: They are having a great old shindig.

Dr Jeanne: And we have some evidence that the males may actually return more often than the females. They have to go away and stack up on fat and produce more eggs, whereas the males are raring to go.

Minnie: They can keep this up all year.

Dr Jeanne: All year, I can’t wait till next season.

Minnie: Yeah, well, I think that’s true, because sea turtles don’t have a diaphragm. So everything is just in there. All of their organs are just in one hole. So yes, you can’t be separating everything. You need to keep all of that space for eggs.

Minnie: And their reproductive tract is long.

Dr Jeanne: It is long. And their ovaries are full of eggs when they arrive. And in fact, by the time they leave, their ovaries often still have yolks in them. And they may be using the unused yolks as energy to help them get back to the feeding area. By that time, they’re quite depleted. You know, their fat stores are way down.

Minnie: Yeah, they can lose, I can’t remember quite what the figure was, but they can lose quite a huge percentage of their body weight over the course of that time. Because, yeah, they go away, get really, really, really fat, and then use all of that to keep them going for up to four months.

Dr Jeanne: They’re quite good at it.

Minnie: Oh, they’re so amazing. I hope everyone who listens can eventually one day in a very safe and well-managed way get to watch sea turtles nest, because it’s such an experience.

Dr Jeanne: Pretty amazing. Pretty amazing.

Minnie: Well, Dr. Jeanne, thank you so much. I think that is going to probably bring us to the end there. It’s been such an interesting conversation. I could go on forever.

I really, really, really appreciate you joining us. It’s been really, really interesting. Thank you so much, Dr. Jeanne. And it’s been a pleasure to meet you.

Dr Jeanne: Thank you, Minnie. It was wonderful meeting you.

Minnie: Thank you all, to everyone who is listening. We would love to hear your thoughts, so please do leave us a review and let us know.

If you would like to learn more about sea turtles and ORP’s work, please visit our website oliveridleyproject.org, where you can also support our work by naming and adopting a sea turtle, adopting one of our sea turtle patients or making a donation.

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We’ll see you for our next episode, and until then, stay turtley awesome.