On our second night of field work we keep with the good luck and collected all the frogs we needed from the old locations inside the Chernobyl Exclusion Zone where they were collected back in 1987.

We started the day in the lab checking all the frogs collected during our first night of work in the Zone. This year the sampling is pretty easy compared with previous seasons in which we collected multiple tissue samples from each individual, so things were fast and easy. First thing we did was to set up our small experiment to look for coloration plasticity in the treefrogs. So, every frogs was photographed and put in a container either with dark or light background. One day later we will take another photo to estimated if coloration has changed with time, and as a consequence of background color. For now, frogs are quiet in their containers at the lab.

Then, we moved to work with the fire-bellied toads (Bombina bombina) taking a small sample from a feet phalanx of the five toads collected during the night in the Azbuchyn lake. This will allow us to compare, at the genomic level, these frogs with frogs collected in the Zone 30 years ago, right after the accident.

Finally, we worked with the other species from which we have old samples, the waterfrogs of the Pelophylax esculentus group. These are a rather complex group of three very similar species, not easy to differentiate at all. So, first thing we did was to take se real photos of their morphology, especially their feet (metatarsal) tubercles. After a quick email check with our colleague and expert on this group, Glib Mazepa (University of Lausanne, Switzerland) we confirmed that all were from the species we wanted, the hybrid Edible frog,.

We also collected a phalanx from these frogs, and all the sampling was finished. Quick and easy from once. So we had time to take good photos in the lab from some of the individuals. These photos that later on are just perfect when given a talk, or asked from a journal for a cover image. Let’s see how many of them appear somewhere in print 🙂

After some time in the hotel to re o es a bit of the little hours of sleep, and an early dinner, we where back to the lab and ready for another night of fieldwork. This time, we went for a locality close to Chernobyl city, in an area with low radiation levels, when we already collected treefrogs last year, and researches collected amphibians back in 1987-1990. Last year it was an easy place, wiijust the right amount of water and plenty of easy frogs to catch. It wasn’t the same this years. The are was a bit overgrown by reeds and had plenty of water, which made frog catching quite challenging. After more than an hour of fighting our way through the reeds and some areas with water level a bit too high we ended on a pond just full of waterfrogs. So, finally we managed to caught 23 individuals. But no fire-bellied toads or treefrogs on sight.

So, we went back to the car, and walk around the area following the distant calls of the fire-bellied toads. After some time walking in the dark, we arrived at a nice pond where the toads were active. There, it was quite challenging first to locate the calling males, and then to catch them before they moved away and deep into the water. So, it took more than an hour to catch the five individuals we needed, but we finally did it.

This morning, it will be time to sample of these individuals, and check the treefrogs of the coloration experiment. Let’s see if we can do this fast. With all these frogs, we don’t need any additional amphibians from the Exclusion Zone this time. The idea now is to focus on sampling environmental microbiome in all the places we have visited since 2026, to have an idea of how the amphibian microbiome is affected by the environmental microbiome, but also to understand the factors (other than radiation) that affecte the diversity and composition of the microbiome in the ponds and lakes of the Exclusion Zone. That means that today afternoon and tomorrow it will be time for us to move around the Zone, from pond to pond sampling waster, soil and sediment microbiome. Really looking forward to mi e through the Zone during daylight!!

We didn’t move much yesterday, but enough to see a group of 3 Przewalski horses (young stallions) near Chernobyl city, and a red fox.

Let’s see how it goes today. Still warm, but with chances of rain. More tomorrow!!