It wasn’t easy, but we ended the night with ten Eastern treefrogs (Hyla orientalis) collected in a new locality near Slavutych. These frogs are extremely important in order to complete and give power to our coloration analyses, since until now we only had two localities outside Chernobyl Exclusion Zone. Again, a long and exhausting night, but a really good one!!

First thing we did in the day (after a fantastic breakfast of orange juice, cappuccino and Benedict eggs!!) was going to the lab for measure, photograph, and took a sample from the Pelophylax frogs collected the previous night. We did all this at the labs of the Chornobyl Research Centre for Nuclear Safety, Radioactive Waste and Radioecology. Our colleague Sergey Gaschak is the deputy head of the Centre and the director of the Radioecology lab. Great facilities with fantastic labs.

Among the frogs we sampled was a huge marsh frog (Pelophylax ridibundus), the biggest frog we have collected in all these years. A massive female of 154 grams!! After sampling her, we had to take some photos as a memory, no doubt.

This time we have a sampling protocol much more simpler than in previous years. We mainly took a photo of each individual, measure the mass, length, width and depth of each frog, and took a phalanx sample for the genomic analyses. In previous years things were much more complicated, since we sampled a lot of different tissues from each individual for genetic and physiological analyses, something that took us about half an hour per frog. Now, in a little more than an hour all the 30 frogs were ready. This also allows us to have time to take some good quality, profile photos of our study species, the kind of photos that later on are fantastic when given talks, presentations, or for working with the media.

“The beast”. Female marsh frog (Pelophylax ridibundus).

Male Centroeuropean green frog (Pelophylax lessonae)

After lunch, we went back to the road. First we released all the frogs collected in the first locality we visited last night. All back to their original pond, as every frog this year. Then, we started to drive around the southwest of Slavutych looking for potential good areas to visit during the night. We find some, with some Pelophylax activity, and many more pretty dry after a spring with little rain in the area.

During this drive we had the chanc to see some wildlife too, including many birds linked to meadow habitats like red-backed shrikes (Lanius collurio), grey partridges (Perdix perdix), white storks (Ciconia ciconia). We also saw, and sometimes moved out of the road, many European pond turtle(Emys orbicularis).


We finally went back to Slavutych for dinner, and back to the car again at 8:30PM. Really a non-stop schedule we have here… We first drive to some of the localities we visited after lunch. No fire-bellied toads calling, no treefrogs. We waited and waited in some localities. Nothing. Not a single amphibian, apart from the Pelophylax that we don’t need anymore.

We moved to other area, closer to the Dniepper river and the Belarusian border. There, we heard treefrogs, finally!! But they were far, far away, in an area of sandy meadows and water channels. Thanks to Sergey’s knowledge of the area, we drove back, making a big circle trying to get closer to the frogs. Everytime we stopped the frogs continued to be far away. It looks impossible to get closer to them, honestly. Finally, thanks again to the driving skills of Sergey and the sturdy “Great Wall” Chinese 4×4, we went straight trough the unknown meadows. Trying to avoid water channels, holes, or whatever in the middle of the absolute darkness. Finally, we arrived close to where the treefrog were calling!! We put on the waders and moved quickly to the pond. Treefrog they were many, but extremely well hidden. It took as one and a half hours to catch ten. But these ten are extremely important, pure go,d in terms of research. They will allow us to have a much more balanced design in our coloration study between contaminated and non-contaminated localities. On the way back to the car, Pablo couldn’t hide a big smile thinking about sampling size, statistic power, and all these things that a researcher thinks about in the field 🙂


Today in the morning we will sample and photograph all these treefrogs, and then we will back into the car releasing them, and start sampling microbiome in the last two localities where we collected frogs. Another great addition to our studies here!! During the night, we will be back to the ponds trying to get these additional five fire-bellied toads and more treefrogs. This may be our last night in the field for this campaign, since we finally leave on Tuesday and will not have much time for sampling that day if we go to the field Monday night. But, let’s see…

We start our day here now. More tomorrow. Enjoy the Sunday!!