Thursday 29 July 2021

Dinaric dreams... of bears and beetles

Last weekend was super intense and all packed in a fantastic two-day adventure in the Dinaric mountains. As Sara had other work to do and didn't seem to like the proposed plan, I (Domen) was joined by two friends who were eager to search for the iconic Alpine Longhorn Beetle Rosalia alpina in the Dinaric forests of central Slovenia. As my two fellows didn't have a plan where to spend the night, we first decided to do a dusk-to-dawn wildlife watching session on the Snežnik plateau. In the evening we were strategically positioned on the edge of the forest, waiting for wildlife to emerge and feed, under a bright full moon. While driving to the spot we already encountered a magnificent Red Deer Cervus elaphus stag close to the road, so our morale was high and the evening seemed promising indeed. Soon after the sun set and still in good light conditions, our dreams came true very quickly: a mother Brown Bear Ursus arctos with cub emerged from the forest and walked through a meadow in full view! For the next half an hour or so we could watch the two bears (the young being 2021-born) wandering around the meadow and looking for food. The female was most probably a young mother, as this is usually the case with bears that wander out of the forest and show well before darkness. Young bears always try to avoid encounters with night-roving older bears (especially alpha males) that rely on darkness for safety. As the site looked incredibly promising, we waited there a considerable amount of time, even when darkness descended. We were hoping to watch some more animals on the meadows enlightened by the full moon's strong light. And of course our patience was rewarded. When the female bear with cub was still around, first a stag Red Deer and then a female appeared, although shortly. Later and rather suddendly, two large black shapes materialised in the moonlight - they were two new bears, certainly adults. The visibility was not very good, so we could only make out the bear's shapes. When the bears left it was then time for a group of Wild Boars Sus scrofa, another strictly nocturnal animal in these forests. Meanwhile it was also lively in the trees around us. We expected to see a Ural Owl hunting on the forest's edge, but in fact we observed 2 different Long-eared Owls Asio otus, certainly a quite rare species in this area (and on Snežnik's plateau in general). At last we also heard a singing Ural Owl Strix uralensis in the trees above our heads, but also two distant Tawny Owls Strix aluco. We were however quite surprised by the complete absence of Edible Dormice Glis glis and their quintessential squeaking noises.

Brown Bear Ursus arctos (last pic by Silvio Davison).
Red Deer Cervus elaphus by the road (by Silvio Davison).
Our spot for the night was a cosy little hill at the edge of the forest, where we wanted to scan the surrounding meadows first thing the next morning. When we woke up at dawn, deer were still out grazing on the meadows. We came across a loose group of 10 Red Deer Cervus elaphus grazing the rocky meadows, all nice males with large velvet antlers. At the very edge of the forest several Roe Deer Capreolus capreolus were around, including a female with two young. It was quite windy, so not ideal for any dawn chorus, although there was a Rock Bunting Emberiza cia singing nearby. Later as the sun rose and the its first rays hit the rocky slopes below us, raptors began to appear. Apart from good numbers of Common Buzzards Buteo buteo and Kestrels Falco tinnucnulus (probably all local birds with juveniles), we were surprised to see a Short-toed Eagle Circaetus gallicus hunting and successfully catching a small reptile (probably a lizard) at around 6.30 in the morning. It was a distinctive bird, with an extremely white plumage colouration and had literally no dark markings on the underparts. Sitting on a pine nearby was another Short-toed Eagle, probably its partner.
Wild night out.
Scanning the rocky meadows at dawn.
Red Deer Cervus elaphus
Roe Deer Capreolus capreolus
Rocky meadows on the edge of Snežnik's plateau.
Great Yellow Gentian Gentiana lutea subsp. symphyandra
Garlic Cress Peltaria alliacea
As the day wore on, we found ourselves driving through the extensive forest roads of the Snežnik & Javorniki mountains, in the direction of the Rakitna plateau. Along the gravel roads we frequently stopped to admire interesting forest butterflies, like the impressive Purple Emperor Apatura iris or the abundant White Admiral Limenitis camilla, two typical summer species of this habitat. Upon reaching the Rakitna plateau, an area of extensive Dinaric forests, but known for its many forest streams, we also spotted an individual of the rare Balkan Goldenring Cordulegaster heros, Slovenia's largest dragonfly, living in small untouched forest streams.
Purple Emperor Apatura iris (by Silvio Davison).
White Admiral Limenitis camilla
Brown Bear's droppings on a forest road.
Balkan Goldenring Cordulegaster heros
"Carniolan" Yellow Bellflower Campanula thyrsoides subsp. carniolica
Finally we reached an area of beech forest where we were supposed to look for the rare Alpine Longhorn Beetle Rosalia alpina (aka Rosalia Longicorn), an endangered Natura 2000 species of international conservation concern (see this post). These attractive beetles, sporting an amazing blue-grey colouring on the elytra (vaguely similar to the much commoner Morimus funereus) live in sunny beech forests, especially those on steep slopes. Like other forest specialists they depend on the presence of dead beech wood, where they lay the eggs. Trees affected by windfall, ice-storms or the like are particularly suitable places for the reproduction of Rosalia Longicorns. Even more attractive to them are freshly-cut beech trunks piled at the side of forest roads by lumberjacks. The smell of freshly-damaged wood is very attractive to the beetles that flock to these logs from far away (Rosalias are excellent fliers). After mating, the female beetles deposit the eggs inside dead wood, where the larva develops and emerges as imago (adult) after three years. The main conservation issue with this species in commercial forests is that the beetles deposit their eggs in log piles that are soon removed by the forestry and the broods are therefore destroyed. Still, checking such log piles in summer is an efficent method of finding the Alpine Longhorn Beetle. And that is exactly what we did. At first the area we worked didn't seem very promising as no log piles were found, but then we came across three large beech trunks stacked at the side of the road and... there it was - a marvellous Rosalia alpina! We then spent a good half an hour there, photographing the beetle, as well as checking the surroudings for any other potential Rosalias, but with no more luck. It was the only one we saw that day and needless to say we were truly overexcited!
Typical view of Rosalia alpina
Alpine Longhorn Beetle Rosalia alpina (last pic by Silvio Davison).
Rosalia addicts.
Wearing the perfect t-shirt for the occasion, as usual!