Wednesday 5 July 2017

Summer wildlife in the Karst

Although summer is frequently considered a quiet time for wildlife observation, there's actually a lot to see in this season. With this post we'd like to present some of the summer wildlife we encountered during our recent trips in the low and high Karst of Western Slovenia and in the Trieste area. At the beginning of the post there will be some birds and other animals we found mostly in the Classical (low) Karst region, while at the end we will present some interesting plants from the High Karst of Trnovski gozd. Although our main interest at the moment is mostly botany and butterflies, don't despair, we still regulary see interesting birds! There we go...
Short-toed Eagle Circaetus gallicus is a true Karst's specialist as it hunts over stony grasslands for reptiles (mostly snakes and lizards). Thus it is mainly found in the south-west of Slovenia, where such habitats are still common. Although it can be frequently seen in the proper habitat, it is a rare breeder with well-spaced breeding territories. Where the neighbouring territories meet, disputes between two or more birds are common. A few days ago we witnessed one such dispute between 3 individuals, over a large good hunting area. Short-toed Eagle is most frequently seen in flight while performing its "hanging" hunting technique, usually late in the morning and around midday. On rarer occasions it can be seen perched on black pines Pinus nigra or pylons (first pic). Being a reptile-specialist it can only find its food during the warm season, so in autumn it leaves Europe and migrates to Africa.
Certainly worth of mentioning is the observation of a pair of Eagle Owls Bubo bubo on the Karst's edge near Trieste. The birds at this time of year aren't singing (juveniles have just left their nest), but they can be still located and observed around dusk. We were lucky with the above bird as it appeared on one of its perches, quite early in the evening, allowing us to have great "daylight" views. The species is another iconic inhabitant of the warmer part of Slovenia, where it breeds on inaccessible, south-facing limestone cliffs. Of course it can be found in the same habitat in the nearby area of Trieste in north-east Italy, where the above photos were taken. In Slovenia there are at least 100 breeding birds, mostly concentrated in the western and central part of the country, which is more mountainous. In recent years new sites are being discovered in eastern Slovenia as well. Where the natural habitat (rocky slopes and cliffs) is lacking, Eagle Owls readily occupy abandoned and active quarries.
In early spring, when Hoopoes Upupa epops return from Africa and sing across Karst's meadows, vineyards and orchards they seem to be quite abundant. However later in the season, when the pairs settle they are not so easy to find. They sing less and even show themselves more rarely. Now by mid summer, juveniles will start to appear and the birds will become more detectable once again. But that's unfortunately for quite a short time, because between August and September most will start their autumn migration to Africa. Although declining, Hoopoes are still widespread countryside birds in Slovenia, preferring the warmer part of the country (mostly in the west and extreme north-east), where they feed mostly on large ground invertebrates (grasshoppers, crickets, mole crickets ect.).
Although we are not specifically looking for them in this period, Middle Spotted Woodpeckers Dendrocopos medius have been frequently seen on our trips recently. The most interesting was the above bird that we found in almost open countryside on the Karst, on a new location for the species, not far from Sežana. This and several other observations we made involved juveniles (with faint colourings) probably on dispersal, discovering new territories. It is quite amazing we can't get rid of them even in mid summer, when our attention is concentrated on completely other things!
One of our targets for this summer was finding a handsome Stag Beetle Lucanus cervus and having a closer look at it. These beetles are quite common in the Karst, as the area is full of oak trees Quercus - their favoured trees. But until now, we have mostly seen them only in flight at dusk. At the end of June and beginning of July the adults emerge from underground, where the larva & pupa have been developing for several years (up to 7). Adult males, recognised by their enlarged mandibles (top two pics), climb on trees and fly around looking for females (last pic). When two or more males meet, disputes occur and the opponents fight each other with their "antlers". The adult beetles live for only a few weeks. In the area where we took the above photos we found up to 10 Stag Beetles of different size and sex. The above male had the most impressive mandibles of all. Target accomplished!
Quite different from the Stag Beetle, but equally impressive due to its size is the Great Capricorn Beetle Cerambyx cerdo. This species belongs to the longhorn beetle family (Cerambycidae) and it can measure up to 6 cm (antennae excluded). It is one of the largest European beetles and certainly the biggest insect we have ever seen! It's interesting that we found the above specimen on the same tree where last year we had two of them (see this post). And that tree wasn't actually far from those occupied by Stag Beetles.
The Dalmatian Algyroides Algyroides nigropunctatus is a colourful lizard that can be commonly encountered among limestone rocks and cliffs close to the Adriatic sea. The species' range stretches to different countries along the Adriatic sea, down to Greece, but in our region it has the northwestern limit of distribution.
Dry stony grasslands, especially those at higher elevations are full of butterflies at this time of year. On one such grassland at the southern edge of Trnovski gozd we counted some 20 or so species. One of them was the rare Great Sooty Satyr Satyrus ferula, in the above photo feeding on Trifolium alpestre.
The southern edge of Trnovski gozd is also well known for its botanical biodiversity. The area is one of the richest on a national level in terms of rare species and biogeographical mix. The above Genista holopetala is a classic example. It was first collected and described right here. In Slovenia it grows nowhere else and belongs to the group of the so-called Liburnic species (those with a north-western Balkanic distribution). Outside Slovenia it can be found down to the Velebit mountains in Croatia.
Another not very impressive, but rare plant is Onobrychis alba. It is only found here and at a few other sites around Ajdovščina. The above photo was taken on mount Kucelj - the highest peak along the southern edge of Trnovski gozd.
Edelweiss Leontopodium alpinum is a plant most often associated with the Alps. But it also grows away from the well-known mountain range. In Slovenia there are some disjuncted locations where this species can be found and Trnovski gozd is an example. The above, quite poor specimen, is one of the very few you can still find in this area. Certainly not like those you can see in the Alps! Nevertheless, from the biogeographical point of view, it is a very interesting species for the area.
Although common on sunny mountain meadows Lilium carniolicum is always a beautiful find. As a backdrop in the above photo is part of the ridge that forms the southern edge of Trnovski gozd. But the prettiest flower of the moment is another lily... one found in the forest...
Lilium martagon is quite common in mountain beech forests of Slovenia and flowers a few weeks later that the other two species. The above shots were taken in the Trnovski gozd (Trnovo forest), along one of the main roads that run through this area. In the second pic you can notice once again, the lily-eating beetle, Lilioceris lilii, a parasite on all species of lilies.
Although this plant is perhaps one of the least impressive of the Slovenian flora, it is also one of the most important! It is named Hladnikia pastinacifolia and is a stenoendemic species of the area of Trnovski gozd - it grows nowhere else in the world! It also belongs to the only endemic plant genus in Slovenia. Hladnikia was named after Franc Hladnik (1773-1844), a famous Slovenian botanist. Speaking about the flora of Trnovski gozd, we simply couldn't neglect this important plant.
Two views from the southern edge of Trnovski gozd; the first pic looking south-east, the second to the north-west. These are perhaps the most scenic views in the whole of Slovenia, where you can catch sight of a great variety of landscapes: from mountains, forests, valleys and the Karst to the Adriatic sea. In both photos the picturesque Vipava valley can be seen, surrounded by forested slopes rising to Trnovski gozd on one side and to the Karst on the other.