nature trip to croatia

                                     Map of Croatia with the main places visited during the trip

After our memorable trip to Morocco in 2019, I never thought it would take me two years to write a trip report again. Of course the COVID-19 pandemic has changed a lot of things in our lifes, and travel options are not the same as before. In 2020 my friend Max Benito and I were carefully planning a new herpetological trip to a tropical rainforest area, but finally we ended at home and almost with some less money (finally we were able to recover it). In 2021 most countries are still closed but we can travel now inside the European Union more easily. As I didn't want to stay two years without a nature trip, I decided to take advantage of an outstanding account and head to the E of Europe. I've never look for herps or birds on other european countries before, so the only european species I had seen were the ones we have in Spain. 

I chose Croatia for some reasons. This country has a wide variety of landscapes and most of the emblematic herp species from E Europe are here, along with some central Europe species and endemics. Other countries like Greece would also be great but we could only go on summer so the heat (and animal activity) would be lower on southern countries. In addition, Croatia host some interesting bird species that could arrange the trip if the herp activity was not as expected. For this trip none of my previouse trip mates were available, so teamed with a new set of young naturalists from my homeland in Valencia: Marcos Real, Arnau Rivera and Guillem de los Santos. Marcos is now an old friend and mate from the Timon Herpetological Association, being Arnau and Guillem two of his university classmates in Biology degree. So, in this trip I was de oldest one... 

This trip was not as thoroughly planned as the prevoiouse ones, because until a few weeks before, it was not clear to us that we all would finally be able to go. However, looking on online databases and with the help of some fellow naturalists I was able to plan a route that would take us through a wide variety of areas and ecosystems with options to see all of the target species. Due to a little problem with my camera that I'll later explain, in this trip the quantity and quality of my photographs are not the same as before, so most of the photos in this report are from my trip mates. I would like to thank them for providing them to me for this report. 

                                       The four croatian explorers in the mood we spent most of the trip: driving! From left to right: Marcos, Guillem, Arnau and me (Luis).

We took our flight from Madrid on August 2th and arrived to Zagreb the following day, after a stop in Milano (Italy). During this stop we had the first of loong series of problems and/or accidents on this trip, as we had to change airports but the available cabs cost a lot of money (more than 300 euro). Luckily, a kind Italian bus driver offered to take us out of hour for a much smaller amount, all of it entirely for his pocket, of course. We finally arrived safe to Zagreb and took our rental car, a nice BMW. 

The plan for this day was to explore some big fish ponds near Zagreb, mainly for birding, and head south to the Istria peninsula to herp on the afternoon and spend the night there. The first part of the plan went well as we stoped in Pisarovina fishponds and quickly spoted the target species: lifer white-tailed eagle (Haliaetus albicilla). As a big fan of raptor birds, seeing europe's largest eagle for the first time was a long-awaited desire. We could enjoy nice views of a juvenile eagle, which at some point flew really close to us, and also of an adult soaring above. We also saw other interesting species as our first pigmy cormorants and a black stork. On this place we also spotted the first herp of the trip, a tricky snake that scaped rapidly after lifting a log (maybe a Natrix?). 

As we had time, we decided to go for other nearby fishpond in order to get better views of adult eagles. On our way we found a place near a stream which looked nice for herping, so we made a stop. The result was quite disapointing: 2 scaped snakes. As consolation prize we could spot some Rana frogs (I think Rana dalmatina, but is complicated here as we could have R. dalmatina, R. temporaria and even R. arvalis). The way to the fishpond was cut off, so we headed back and continue to Istria. On our way we found a Coronella austriaca under some wood sheets. Perhaps the less desired croatian snake for me, but better than nothing!

On our way to Istria I had the first on a series of "accidents" in this trip, when, due to some confusion, I ran over my backpack with the car, as I thought that my mates had put it inside it, which was not the case. Inside the bag I had the binoculars and all my lenses except for the telelens, which fortunately was already in the car with the camera itself. The result was my binoculars with uncoordinated focus between the two sides, and all camera lenses with the autofocus broken. Miraculously, the entire optic was undamaged, not a single lens cracked. Of course, that was the reason I took not so many pictures the rest of the trip... Once in Istria we herp on a promising area on the afternoon and found nothing but a couple Lacerta viridis. Reptile activity appeared to be very low, so it would be for the rest of the trip. Maybe the intense heat wave on the week before had caused many reptiles to enter into inactivity or estivation. 

This day we began with a new herpetological searh on Istria, and another big failure, with again zero snake activity and only a couple Lacerta. At mid morning was the time to see the species that has taken us to Istria, one of the most emblematic european amphibians, the olm (Proteus anguinus). This subterranean salamander is a true relict and a very difficult species to look for, only observable in a couple places, mainly in Slovenia, but I found out that they can be seen also in Baredine cave on Istria. The experience was not very rewarding. The cave appearence was nice but the place was full of turists and they only gave us about 5 minutes to see the only two olms that were in a little puddle on the bottom of the cave (60m down the ground). As we found out asking the guides, this two olms were taken here from an even deeper area of the cave, were they occur naturaly, but which is inaccesible without the use of caving equipment. Therefore, despite the fact that they are incredible animals, the experience was somewhat bittersweet. I hope to see them better on Slovenia on the future, when inter-country travel is easier and safer!

After the cave, our plan was to look for mountain species and we went to Risnjak National Park, close to the slovenian border. This area has well preserved mature forest which are home to a rich animal community, with emblematic mammals such as the lynx or the brown bear. We begin on a meadow near a ski resort where we rescued a big common toad (Bufo bufo) from a cistern. We found nothing more apart from a couple slow worms (Anguis fragilis). On a nearby pond, I found two yellow-bellied toads (Bombina variegata), but they were inside the pond and we couldn't catch them to get a better view. These would be the only specimens of the species in the entire trip, so they remain as another pending account for me. Then we head up to a mountain above tree line where we wanted to search for adders (Vipera berus), rock lizards (Iberolacerta horvathi) and alpine salamanders (Salamandra atra), but again the target species failed (it was cloudy with some wind) and we only found tons of slow worms. However, the landscapes were great. As we went down, we took a brief view on the pond and found three juvenile grass snakes (Natrix natrix) under stones. Later, already at night, on our way back through the forest, we saw one unexpected species, an ural owl (Strix uralensis). It flew very close to the car but the sight was brief so we have no photographs. Likewise, one of the best encounters of the trip!

Our next destination was the island of Krk, where I read lots of trip reports of people finding nice herp stuff. We arrived to a campsite at night, and while my companions were setting up the tent, I wandered a little way off to satisfy my biological needs and in a small glimpse I saw a snake crawling on a landslide. One of our most desired species, the european cat snake (Telescopus fallax), an adult of decent size. Later on the night we went herping and Arnau found other, smaller, individual. That same night it was a big storm on the campsite, with lots of wind and lightning. Our tent survived as a champion, but some water went inside, wetting more than one thing...

After the storm of the previous night, the morning was cloudy with some moments of sun, so it seemed perfect for reptile activity. We set up camp and headed for the north of the island, near the airport. There, the scrubland habitat with some stone walls and big amounts of garbage (even large pieces of sheet), looked like an herpers paradise. Gradually, some reptile species were showing. The most abundant the dalmatian wall lizard (Podarcis melisellensis), and also some italian wall lizards (Podarcis sicula), and some of the impressive dalmatian algyroides (Algyroides nigropunctatus), on the rocky outcrops. But our main target was to find snakes and the european glass lizard, so we didn't spend time taking pictures of these lizards, thinking that we would see them the rest of the trip. The same happend with the big balkan green lizards (Lacerta trilineata), that were also quite common here. After a long seatch and lots of promising stuff lifted with no result, we found a snake, a balcan whip snake (Hierophis gemonensis). She wasn't one of my most desired snakes, but I admit that was nicer than I expected, even forgetting that it managed to escape before taking good pictures. The rest of the day we headed to our final destination, Paklenika National Park, were we stayed on the official campsite for the rest of the trip. We had time to carry out a small nocturnal survey of the coastal area, where we found a new specimen of cat snake and lots of fat dormouse (Glis glis), a species I've never succeded to find on Spain. 

This day we get up early on the morning and head up to the highlands of the national park to look for nose-horned vipers (Vipera ammodytes). On our way we saw a pigmy cormorant (Microcarbo pygmaeus) near the coastal road, which was oberved within a close distance. Once on the highlands, the habitat up there was a very cool one with lots of promising stone walls. The night before we had another strong thunderstorm with lots of rain, and when we set foot in the field we saw more reptile activity than ever before on the entire trip. Specially abundant were the balkan wall lizards and the balkan green lizards, of which I could see some specimens basking at close range, but unfortunately I did not have my camera with me because I was looking for vipers. After not so long I found a big horned viper quietly basking along a stone wall, a really impressive animal. We looked for a while longer and only saw this one, which was also on shed (perhaps that's why it was active on summer). What we did saw were some adult balkan whip snakes, very fast animals but finally Guillem managed to catch a pretty one for the photos. We celebrate the succesful morning with a great meal on a local restaurant! 

On the afternoon we decided to look for a local bird speciality, the western rock nuthatch (Sitta neumayer). We went to the Mala Paklenika canyon, a spectacular dry gorge on the park. As for reptiles, there was practically no activity and only a few lizards were seen. Marcos and I even climbed the canyon slope until we reached a large cave with several nests of nuthatches on the wall, but it was not until later, on the way down, that we began to hear their characteristic calls. Finally one individual perched very close, but only for a few seconds. Lifer anyway!

Nose-horned viper (Vipera ammodytes ammodytes)

Balkan whip snake (Hierophis gemonensis)

This day we got up even earlier than the previouse one. We wanted to visit Mount Dinara, the higher peak of Croatia, to look for some mountain specialities, and as it is a long way up with the car and then walking, we needed to be there short after sunrise to guarantee a high reptile activity. But sometimes plans don't go as expected, and the fact that we were driving so early in the morning caused a roe deer to cross in front of the car. Everything went so fast that even though we were not going very fast we could not avoid it and we ran over it.  Although no personal injuries were reported, the rental car was somewhat damaged and we had to call the police to file an insurance report. They took a while to appear, and when they arrive they put me inside their car with no explanation and they took me a little further back to show me the typical animal crossing danger sign, which is practically everywhere here. They said that we had to pay a 100 euro fine for killing the animal in a road with that sign, as they thought that if we ran over it, it was because we were going very fast. As much as I tried to explain to them that the deer suddenly ran off with no room to maneuver, their english was not very good and in the end we decided not to argue any more and pay the fine. The final result were about 4 hours lost, on the best herping time of the day, and a car with the air conditioner broken, which resulted a torture on the rest of the trip. 

We arrived at the parking site on Dinara at about 12 a.m. and started herping, finding almost only lizards, but the three Lacerta species of Croatia: L. viridis, L. trilineata and L. agilis, the latter a new species for us. After a bried meal we started our walk upwards towards the habitat of the meadow viper (Vipera ursinii). The route was hard due to the heat and the slope, added to the intense search for reptiles. Activity rapidly fall down, and was imposible to find other species, such as Iberolacerta horvathi on the rocky areas. We ended the trip without none of that species. Luckily, there were lots of tasty raspberries up there to calm our thirst. When we were already up, Guillem and Marcos, very tired, remained seated for a while while Arnau and I continued our search. And it was then when Guillem could see the small snake enter a crevice between stones. Finally, and by a miracle, we found the target species, the relict from the ice age. The truth is that it was very cool to find it in that highland landscape, with grasslands and scattered trees, which certainly reminded us of what it would be all over Europe during the glacial periods. It looked like a mammoth was going to appear on the scene at any moment haha.

Regarding other finds, we saw some cool birds, highlighting a flock of rock pertridges (Alectoris graecca), and a couple of black woodpeckers (Dryobates martius) on our way down through the forest at sunset. And going down the mountain with the car we also had other interesting encounters, such as a our only green toads (Bufotes viridis) of the trip, a hedgehog, and a big wild boar (which luckily we did not run over).

Meadow viper (Vipera ursinii spp.)

Despite our successes with mountain species, we had not yet managed to find many of the coastal species, especially snakes, throughout our trip. From this moment on, moreover, the already high temperatures rose, starting a new heat wave in Croatia. We decided to look on the area around Vransko lake, were numerose trip reports have shown good results. We arrive early as usual, but also as usual we didn't find nothing in our herping search, in spite of good looking habitats and lots of stuff to lift. We then headed to the lake and saw some birds on a walk along the shore. I also wanted to see the dragonfly Lindenia tetraphylla, which is found here, but the date was too late for them. After the walk, we consoled ourselves with delicious pizza and beers. The rest of the afternoon we did some snorkel on a local bay, seeing some dead Pinna nobilis and not a lot of fish. At sunset we find another good looking area with lots of garbage, but only tortoises (Testudo hermanni), were found. Finally, at night we saw our only snake of the day... another big cat snake, and had a encounter with a local old policeman who retained us for a while when he saw us there at night, without paying any atention to our explanations.

One of our main targets for this trip were some endemic lizards, and among all a colorful species, the sharp-snouted lizard (Dalmatolacerta oxycephala). In Croatia this species lives on the southern coastal part, being Dubrovnik the most famouse place to see them. As the way to that city would be too long and difficult (as we needed to travel trough Bosnia), we decided to look for a place nearby. After some research, I decided to try on Pisarovina river, which formes a beautiful gorge near the city of Split. I marked a site where a path goes down to the river and we went there. Although there did not appear to be much movement at first, the target species soon emerged, seeing a single adult and several juveniles. A truly beautiful species, we were lucky to see them active despite the heat, as we mostly found them in the shade. We also saw other interesting finds, such as better views of dalmatian algyroides (Algyroides nigropunctatus), another amazing lacertid. On the river we caught a big dice snake (Natrix tesselata) and found other specimens swimming and hunting. Our only dice snakes of the trip, a species quite similar to our spanish Natrix maura, but with even higher adaptation to the aquatic lifestyle. We liked that place a lot, was one of the most enjoyable mornings of the entire trip! On our way back to the car, we found another cat snake, this time during the day! It seems that destiny didn't want us to see any other snake species than that one... In the afternoon, after a noon of heat torture, we explored some ruins on our way to Paklenika where we found tortoises and our only Pseudopus of the trip... which had been killed by someone weeks before. Definetly they show zero activity on hot summers. 

We started this day as always, looking for coastal snakes at sunrise. And, as always, we found nothing. So, we decided to explore the most famouse part of the national park, the Velika Paklenika canyon. Maybe on this shaded gorge, snakes were more active that on the coastal areas. The gorge was plenty of people and climbers, but the landscape was beautiful and as soon as the water appeared, we followed the river bed crossing much less people than on the path. The undisputed stars of the day were the grass snakes (Natrix natrix), all juveniles or subadults and most of them  with the striped "persa" morphotype. We also found some common toads and dalmatian algyroides, and not so much more. At the end of the morning, Marcos got separated from us and we thought he had gone back downstream to the car, so we headed back. But no, he had continued upstream and found an adult Aesculapian snake (Zamenis longissimus). He thought we were still further up the river but he was wrong. So he was the only one to enjoy this species, so difficult to see in Spain. Next time the walkie talkies won't fail.... That day we get dinner late and spent our last afternoon in Paklenika with another failed search for coastal snakes and glass lizards.

Last day of the trip, and finally we have learned the lesson that eastern mediterranean snakes are imposible to find on summer. That's why we decided to spend the last morning on the highland viper habitat of Paklenika in order to find more Vipera ammodytes.  Up there reptile activity was not as high as in our previouse visit but much more higher than on the coast. We saw several balkan whip snakes, lizards and finally I caught one big male ammodytes, a pretty one with the red tail. Good animal to end the trip with. After packing the tent and all our stuff we headed north and in our way to Zagreb we stopped on Plitvice lakes N.P. We arrived a bit late so we didn't see much reptiles or birds, but the place was amazing, one of the most beatuful places I have visited ever. We only had time to visit one of the waterfalls that separate these travertine lakes, and it is a site that I really want to return and visit more thoroughly. The highlights for me were the dragonflyes Aeshna grandis and Somatochlora meridionalis, cool but impossible to photograph whith sunset light. On our way back, at nigth, we saw plenty of amphibians on the road, of three species: Bufo bufo, Rana temporaria, and a novelty for us: Rana dalmatina. We arrived to Zagreb and leave the car on the rental place, on the walk back to the airport we have a great encounter with a family of little owl to end the trip.

Nose-horned viper (Vipera ammodytes)

Summer is definitely not the best time to herp in the Mediterranean, especially if you get caught in a heat wave and numerous thunderstorms. All this explains why reptile activity on our trip was very low, with intensive searches that yielded no results. We learned too late that looking for coastal species was useless, our desire to see them was stronger, and perhaps it would have been better to leave the coast earlier and move inland or highland, where we could have been more successful with the species there, some of them we did not see (such as Vipera berus bosniensis). Nevertheless, we saw many things, some of them long-dreamed-of species, and it was not bad for an impromptu trip and our first naturalist trip in Europe outside the Iberian Peninsula. I fell in love with Croatian landscapes and ecosystems, and I am already looking forward to visiting the country again, hopefully this time in spring! 

Finally I thank all fellow naturalists who helped us and provide spots for the trip: Rubén Sánchez, Jeroen Speybroeck, Gert Jan Verspui and Gabri Martínez. 

Herp species list

Pelophylax ridibunda

Rana temporaria

Rana dalmatina

Bufo bufo

Bufotes viridis

Bombina variegata

Proteus anguinus

Triturus sp. (Lar)

Salamandra salamandra (Lar)

Testudo hermanni

Podarcis muralis

Podarcis sicula

Podarcis melisellensis

Algyroides nigropunctatus

Dalmatolacerta oxycephala

Lacerta viridis

Lacerta trilineata

Lacerta agilis

Anguis fragilis

Coronella austriaca x1

Hierophis gemonensis x10

Zamenis longissimus x1*

Natrix natrix x9

Natrix tesselata x5

Telescopus fallax x5

Vipera ammodytes x2

Vipera ursinii x1

*Only seen by Marcos

eBird checklists:

https://ebird.org/checklist/S92694286

https://ebird.org/checklist/S92695059

https://ebird.org/checklist/S92764029

https://ebird.org/checklist/S92827972

https://ebird.org/checklist/S92834441

https://ebird.org/checklist/S92852115

https://ebird.org/checklist/S93076447

https://ebird.org/checklist/S92930177

https://ebird.org/checklist/S93005456

https://ebird.org/checklist/S93076469

https://ebird.org/checklist/S93105019