Here is the Caletas Update from January and February!

THE BAULA STORY ENDS – LESSONS LEARNT

Yes, I was writing a lot about Mrs. Baula. She was also the most special, mysterious, fascinating and frustrating turtle mom I ever met. She reminded me that sea turtles can be unpredictable and surprising and are not fully understood yet – their mysteries not fully revealed yet. Plus: each sea turtle has a distinct character – oh yes, you read right! Some are little divas, a few are very shy, others are straight forward and bad-ass. Some of them nest in the most light-polluted areas with twenty people standing around and touching them while others run back into the sea as soon as they hear an unfamiliar sound.
But Mrs. Baula also reminded me once again how awesome and important hatcheries are – and will be in the future, with climate change, beach degradation and all that other stuff.

Altogether, she came NINE times to Caletas to nest – four of those nests got protected in our hatchery, four others were left in-situ on the beach and one was lost to the tide right after it had been laid.

Our first two hatchery nests were a success – with hatch rates of above 70 %, which is considered relatively high for relocated Leatherback nests.

So we were all pretty excited to find some “natural” hatchlings, emerging from an untouched nest on the beach in the middle of the night. For about two weeks, we had people sleeping out at the in-situ nests, waking up every half hour to check the area for any signs of hatchling emergence. We wanted to find the babies, guide them safely to the water and mark the nest location to be able to do an exhumation the next day.
Those Baula nest sleepovers were simply amazing! Now in the dry season, nights are comfortably chilly, the sky is clear and full of eternal stars or an overwhelming moon, no mosquitoes or other bugs bother you. You lie on the sand right next to a Leatherback nest, with the constant excitement of maybe finding a couple of hatchlings walking down the beach or having them walk right into you while you’re sleeping – then the patrol teams stop by for a quick visit, and quite often we had visits from Olive Ridley turtles nesting close-by. It was – again – simply amazing.


However, I got impatient when the first in-situ nest had incubated for 65 days – being five days “overdue” – and nothing happened. So I decided to have a last desperate try on finding the nest to see what was going on: had we missed the hatchlings, or do they take such a long time to incubate? Were there even eggs in the sand? How can we be so sure if we never actually saw the turtle depositing them?

I made my team look for the nest – we poked around with long sticks, dug up the top sand layer of the whole camouflage area, then started to dig down at random spots. And yes, my dear turtle friends, who happened to find the nest by just “randomly” digging down somewhere? It was me! 🙂 So please let me be proud of my “turtle sense” which I seem to develop sometimes 😀 (no, it was NOT just pure chance!).

The eggs we found looked perfectly round and white, as if they had just been laid. By now, though, the hatchlings should be on their way up already! After consulting my supervisor we decided to exhume the nest. We took out the first egg and opened it carefully – still hoping those guys just took an eternity to develop – and we found a dead embryo. So we dug up the whole thing, more than 70 eggs, and the great majority of them contained dead embryos.

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Arghhhhhhhhh

What a huge disappointment!!!!
All those embryos died within the same one or two weeks of their incubation – and the most likely reason for this is temperature – the sand must have gotten too hot.

We realized that we had guarded dead embryos for all those nights. The following days, we dug up the second and third in-situ nests. Again, finding the nests was pretty easy and quick – you just need a team of five strong, willing sea turtle conservationists with long sticks and shovels, you dig up the top 10 or 20 cm and then start poking – you will feel where the sand is a lot softer than anywhere else, just as with other turtle species’ nests – that’s where you dig down.

The second and third in-situ nests had – again – a hatch rate of 0%. Instead, they had up to 85 totally undeveloped eggs – there weren’t even embryos, just egg yolk, no sign of any life ever in there.

 

Caletas beach was definitely too hot for those Leatherback eggs. High up in the dry sand – safe from any occasional tidal wash-over – temperatures must have skyrocketed during the sunny dry season. Our hatchery, however, is shaded – which seemed to create better incubation temperatures.

I read a lot of sea turtle manuals and papers where it says that hatcheries should be a last option for sea turtle conservation, as they give so much potential for human failure and poor practice, require a lot of work and resources and a good monitoring of temperatures and other potentially problematic issues. Instead, nests should always be left in-situ where possible.
But nature is failing right now as well. Okay, I mean, it is probably a consequence of climate change and the hereby intensified El Nino Phenomenon which was recorded this year and brought exceptionally dry and hot conditions to this part of the world.
But let me ask: Have Leatherback nests at Caletas ever hatched in the past decade? Was it really only this year that the temperatures exceeded lethal limits?

This example shows that hatcheries are really needed in the future – because they give the opportunity to influence natural factors which would lead to failure otherwise – you can influence the amount of sun and water a nest receives, monitor its temperatures, moisture and gas levels, and the best of all: you can change the conditions (apply more shading, start watering nests etc.) as soon as you find out that there is a problem. You can create the best incubation conditions. You can play god – because in such a greatly modified world than ours you need to (also see my Hatchery Talk).

Another thing I learned is that Leatherback nests are findable. Having no experience with this species, I heard that it is nearly impossible to find them if you do not see where the eggs are deposited, and that it would take too much effort and time to try – by then, the eggs shouldn’t be moved anymore anyway. And since Leatherback nests are relatively safe from poaching and predation (simply because they are so deep and thus out of reach for raccoons, skunks and Costa Ricans), it is a good idea to have some nests incubating in their natural environment.
If I could turn back time now…. I would have totally tried to find those nests. But in the end you are always wiser.
I mean, who would have imagined that….

Read also this paper about the Eastern Pacific Leatherbacks and decreased hatch and emergence rates during the warmer and drier El Nino years.


After all this desperation about undeveloped eggs, let’s get some good news:
The third nest in the hatchery DID successfully hatch, just as the ones before. We had a good success rate of close to 70 %.
We expected the hatchlings to emerge early in the night as I had found a few heads really really close to the surface during my “can’t-wait-I’m-so-impatient”-dig-down in the afternoon. But the little guys took forever to make that last final step to actually start moving! Me and two of my assistants sat in the hatchery for an hour to watch them emerge. Well, let me tell you a secret: we helped them a little bit.
Sleepy hatchlings usually “wake up” when there is some movement going on above and around them, as they think it is their brothers and sisters which are already heading towards the sea! As for logistical reasons we couldn’t wait any longer (well, we just wanted to release them with the whole team…) we started putting some previously hatched Olive Ridleys on top of the nest, so that them crawling around would accelerate the emergence of the Baby Baula’s 🙂

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And now let’s watch this cute little guy making its way to the sea 🙂

 

DAYTIME SURPRISES

While all that stuff with the In-situ nests happened, the Olive Ridleys thought they’d better make up for it and give us some positive surprises. So were several daytime nesters found on the beach, and with daytime I do not mean during dusk or during dawn, no, they literally came at 3 in the afternoon, when the sand is still so hot that we don’t even dare to walk barefoot on the beach!

Daytime hatchling emergences happen here and there throughout the entire season. You’d explain tourists and volunteers alike: “hatchlings come up once the temperature drops in the late afternoon or anytime during the night”, just to step into the hatchery at midday and see 60 lively babies going wild within the nest basket. Again, this gives great opportunities for photo shoots – so here are some pictures of
the real stars of Caletas beach – the Olive Ridleys
.

 

 

SO HOT…

Overall hatch success is very low at the moment – let’s estimate it to be around 60 % – and a lot of the unhatched eggs have half developed embryos inside. This shows that the conditions inside the nests – temperature, moisture and / or gas levels (less oxygen, more Carbondioxide) reached unfavorable numbers for at least a few of them – probably the ones in the center of the nest.

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He is just one of many others…

However, we do not know the real reason for all those dead embryos – is it still too hot, even though we water the nests every day and apply some additional shading when they are close to hatching? Does our watering and extra-shading maybe even harm those nests in any way? Would it be better to just leave the sand as dry as it naturally would be at this time of the year? Or should we keep fighting against the seemingful harmful natural conditions?

I know that embryos can die if the sand is too moist, because then they do not get enough oxygen by diffusion through the sand, so you literally “drown” them inside the egg. However, I do not have the feeling that we are pouring too much water on them – the sand seems to have a good moisture level.

So what are we doing wrong? Why are our hatching rates not as phenomenal as they used to be?

 

Another factor is that we do not have recent temperature data from inside the nests which have been watered throughout their incubation. Looking at this data could show us if the temperatures are still too high or favourable – which would tell us that it must be something else that is unfavourable.
Incubation duration can be an indicator for nest temperatures – the faster a nest develops, the warmer it is. Most nests incubate for 47 to 48 days at the moment. Extraordinarily hot nests would have shorter incubation periods, though. And back at the beginning of the season we had the same incubation duration and that was when we had all those good nests of above 90 %.

So to conclude this: there is something happening at a certain stage of embryonic development which causes the death of many. It is not clear if success rates would be better or worse without our intervention in this case. There are no studies about the success of Olive Ridley in-situ nests on Caletas beach, but the Leatherback nests did not hatch.
I hope this little mystery will be able to be solved in the future – maybe with more measuring equipment and research. As for me, I just have to accept those low rates for now – too bad, as my plan was to have a record-breaking overall success rate of above 90%.

 

CALETAS SHOWING OFF ITS BEAUTY

 

 

CAMP AND WORK LIFE

On the 6th of February we stopped relocating nests to our hatchery. This has the simple reason that Caletas only runs until the end of March, so by then, all the nest need to have hatched.
We had a pretty good run in our “countdown week”, as we were able to relocate between two and six nests every night, thanks to an overall high turtle activity.
Now, we still do night patrols but leave all nests in-situ. Our primary goal now is to encounter the turtles, tag them and collect a bit more data on them.

Turtle work these days is definitely different, maybe comparable with the first month of this season when there wasn’t any hatchery work to do. I have six research assistants right now – more than I ever had before. Adding the numerous volunteers we’ve been receiving since December, we’ve been able to do a loooot of patrols. Four patrols a night with three people in each patrol team was definitely a noticeable change from the high season, when we were suffering from permanent personnel shortage. Also, we do not have to do double shifts anymore (that means, 3hr-patrols plus 1 or 2hr-hatchery shifts) but either patrol OR hatchery. Then, nesting activity has definitely gone down in those past couple of weeks. We walk more during patrols but work less – and sleep a lot more altogether. Coming back late from patrol? No, we rather come back half an hour early. Running to bed right after dinner at 6:30 pm? No, we rather stay up until 8 or 9  until we truly feel tired.

Yes, we have become lazy – or are we just not over-worked any more?

And during the day? With such a “big team”, everyone has two chores maximum. Those are done within half an hour. What do you do then? It is TERRIBLY HOT these days, so you cannot go out unless you dip into the rock pools or find a rare shaded spot. People start getting sick of reading all day long. They started playing cards, making crafts, daydreaming in hammocks, exploring Caletas’ surroundings, watching birds and other wildlife… and you still hear from time to time that they feel bored. The afternoons are mostly free, now that there is only one or two exhumations per day. One person is kept busy, seven others are not.

Other things that keep us entertained during the day is watching Iguanas invading camp and trying to steel our fruits and playing a shit ton of Candy Crush.

 

Our food situation also changed. After being spoilt for many months – because we had fewer people but seemingly the same amount of food and fresh produce as now – we had to learn to cook differently with what we’ve got. Now we have to use protein-rich, thus filling legumes such as beans, chickpeas and lentils on a daily basis. While beans are mostly accepted among the team, lentils and chickpeas are being avoided whenever possible. No one really likes them. So how do you make eight people eat something every third day that they cannot stand, and which gives some of them bloated stomachs or other digestion problems? And how do you keep all those picky, diversity-longing, western youngsters happy when they are eating beans for breakfast, lunch AND dinner? And to be honest, how can I convince everyone of the deliciousness of those foods when – after nearly eight months – I am sooo sick of it as well?

However – I want to stay with the healthy diet from Caletas when I am back in Germany – more freshly cooked vegetables, lots of fruits and rice and water (who knows me knows that I usually only drink IceTea or gassy drinks!), less chocolate, cookies and gummibears – instead I want to keep baking 🙂


So I have only two more weeks in the heat – then I am back in Germany. I have traveled a lot before, but I have never stayed in just ONE place abroad for longer than 6 months. How will it feel to leave a place forever that feels like home?

The good thing is – and that’s what I have learned over the years – that there are a lot of places in this world that can feel like home to me. So I will leave one home, but always find a new one which might just be as good as the old one.

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