León herping: Spring/Summer 2020

It's time to bring a post here dedicated to my current area of residence here in Spain, the province of León. Located in the NW quarter of the Iberian Peninsula, this region hosts a great variety of habitats, from mediterranean to eurosiberian and mountain environments, which makes León one of the richest areas of Iberia in terms of variety of amphibians and reptiles. My intention in this post is to make a summary of my herp observations inside the province in this 2020 season. It has been an atypical herping year due to the quarantine imposed for the covid disease, which made impossible to go out to the field during some of the best period here, all April and the first half of May. In spite of that, the rest of May and June are also good months here specially for reptile activity, and I have been able to enjoy lots of great encounters. My incursions to the field in search of herps have been primarily during the weekends, taking advantage of the scarce free time that my Phd allows, but also I had some encounters during my research fieldwork.

I'm going to divide this post by talking about the four main areas I've herp here, the two main mountain ranges of the province (Cantabrian Cordillera and Montes de León), the mediterranean plains of the iberian northern plateau and the surroundings of León city. Each one with its particular sort of habitats and different herps. 

Located in the SW of the León province, shared in part with neighbour Zamora and Galicia, Montes de León is an area with a few parallel mountain ranges like the Sierra del Teleno, Sierra de la Cabrera and Montes Aquilianos. This area ranges from about 600m in the lower valleys to more than 2000m in the summits. The climate is humid mediterranean and the habitat dominated by oak forests (Quercus ilex, Quercus pyrenaica), pastures, rocky areas and scrublands. The areas near the rivers and streams are the best to look for herps here. For me the star of this area is the iberian emerald lizard (Lacerta schreibieri), perhaps my favourite european lizard and an abundant species along some rivers in the area. They tend to occupy the riverside forests, and leave the dryer slopes for the ocellated lizards (Timon lepidus). Just before and after the quarantine I visited one particular river I discovered full of this beautiful lizards, enjoying some great observations of the males in their colorful breeding suits, and also females and juveniles.   

Other herps that can be found along this rivers are the iberian stream frogs (Rana iberica), other lizards like the Bocage's lizard (Podarcis bocagei), and snakes, such as the viperine water snake (Natrix maura), which tend to be large and dark here. I also found some smooth snakes of the two species (Coronella austriaca and Coronella girondica), and cantabrian vipers (Vipera seoanei) with pale morphs. In more higher places, the mountain lakes and rocky areas host new species like the Galan's rock lizard (Iberolacerta galani), and I could encounter one cool adult iberian grass snake (Natrix astreptophora), one of my favourite local snakes. 

The Cantabrian Cordillera occupies the entire northern half of the León province. This is a higher mountain range with more humid climate, so its herpetofauna has typical north european species like the reddish frog (Rana temporaria) or the viviparous lizard (Zootoca vivipara, subsp. louislantzi). In the bushes is frequent to encounter cantabrian vipers (Vipera seoanei) with different colour patterns, and near the water bodies inhabits the iberian grass snake. Also, this area has the greatest landscapes!

Most of León province is inside the Iberian Northern Plateau, a plain and dry area with mediterranean climate, dominated by croplands and forest patches. Here is where I'm conducting the research for my Phd thesis, sampling natural ponds and studying their amphibian community. So, during my fieldwork I could observe most of the area's specialities, like the iberian treefrogs (Hyla molleri) and the western spadefoots (Pelobates cultripes), two of the species I'm currently working on their dispersal ecology, via genetic analysis. During my nights on the field to catch amphibians, I also encountered a couple snakes, specially southern smooth snakes (Coronella girondica), which here are bigger and more reddish than in other places, as I've observed. I think this could be due to the absence of other, bigger, terrestrial snake species in the northern part of the León plateau, where my Phd ponds are located.

In the southern part of the province inhabits the king of all iberian snakes and my personal favourite, the montpellier snake (Malpolon monspessulanus). I've encountered more than 10 specimens of this spectacular reptile during this spring, providing also new and relevant information about its distribution in its northern range limit. This powerful snake is expected to be favoured by the climate change and its range in León will expand if years tend to be warmer in the future, at the expense of less thermophilous species like the vipers and smooth snakes. 

The last place is perhaps the most surprising of all, the very surroundings of the city, León. During the final part of the covid quarantine we only were allowed to move a few kilometers and inside our municipality of residence, so I was forced to find good herping places near my home, accessible by foot. As that was in very good dates for herps here (May), I could discover some great places on the outskirts of the city. An abandoned building just outside the city, where some people tend to go to drink and hang out, was proven to be a paradise for iberian greatest lizard, the ocellated lizard (Timon lepidus). There I found lots of individuals not so afraid of me as they usually are (probably they are used to people passing by), so I could make some in situ photos, normally difficult thing with this species. In spite of their size and colourness, people didn't notice the presence of this big reptiles until they saw me pointed them with my camera! I also found here a couple southern smooth snakes (Coronella girondica), one of them really big for the species with almost 80cm. 

But the star species of my "urban herping" has been with no doubt the Seoane's viper (Vipera seoanei), as I found a place not far from the city with a good population of this venomous snakes, where they can be seen very easy on spring. Here this species is in its southern limit. The mediterranean and dry climate is not very suitable to them, but they manage to survive due to the great abundance of rodents. This specimens are among the "cantabrica" morphotype, previously recognized as a subspecies. I have started a study on this interesting population, and by the moment I've found ten different adults, all females as I missed their breeding time (females are more active after mating). Most of them were really big for this species, and showed a variety of grey and brown colourations. First, I show you a collection of photos of the individuals from this suburban population: 

Then, here you have a collection of their dorsal patterns:

This will be a very unusual year. Due to the current pandemic situation our herping plans outside Spain have gone to nothing... Luckily, I live in a region which is a true herping paradise and while I'm waiting to go back to the tropics there are still some very cool species to discover here, and in every encounter you know more about them, their ecology and habits. In the end the goal of all my research here is to provide knowledge about this misunderstood animals to grant that future generations wills still enjoying the variety of colourations, behaviours and shapes of the iberian herpetofauna, of which León is one of the best parts of the peninsula to discover them. 

There are still some mysterious herp species that I couldn't encountered during my field journeys here, specially three snakes which status in León is unclear: the ladder snake (Zamenis scalaris), the aesculapian snake (Zamenis longissimus) and the lataste's viper (Vipera latastei). I expect to see them before ending my staying here! For ending, I have to mention and thank all friends that have came with me during any of my leonese journeys in search of herps: Martín Rey, Rubén de Prado, María Borrego, Marta Borrego, Alberto Benito, Alex Cachorro, Jorge Peláez, Nacho García, Aitana Barriuso, Ainhoa Pérez, Javier Burgos, Ángel Gálvez, Ferrán Giménez, María Revilla and Jorge Pérez. I almost never had to go to the field alone. It is great to see this whole lot of people interested in this fascinating animals!!