Saturday 23 November 2019

Leptodirus hochenwartii - endemic cave beetle

Slovenian caves are amazing places to go searching for rare wildlife, regardless of the season and the outside weather conditions. Caves have a constant air temperature throughout the year, a high air humidity and are dominated by complete darkness. Life in the underground goes on following its own rhythm since millenia and animals living here are specifically adapted to a slow and sight-less existance. Most cave animals are very small (mostly invertebrates) and are usually also difficult to see. 
There are more than 10.000 known caves in Slovenia, mostly in the central and western part of the country, lying on limestone. The Karst, where we live is absolutely full of caves and our fortune is to be able to explore them and find very rare animals not far from home.
Today the weather was cloudy and wet, thus ideal to escape from the surface's late-autumn mood and explore a cave in search of rare beetles.
Entering the cave...
Inside the cave.
Small pools of water - ideal places to find cave animals.
The first stage of a stalactite.
Odd rock formations.

Our main target was the rare and bizzare Narrow-necked Cave Beetle Leptodirus hochenwartii, the first described cave beetle in the world. It was first found in 1831 in the famous Postojna cave by Luka Čeč, a local cave guide who actually discovered the inner parts of the same cave about a decade earlier. More detailed info about the discovery of Leptodirus hochenwartii can be found in this excellent article.
The discovery of this amazing beetle triggered the active search for other cave animals and later the development of speleobiology. There are now 400-450 known species of cave animals in the Slovenian Karst and Slovenia is known worldwide as the cradle of speleobiology.
The Narrow-necked Cave Beetle is a true troglobite, meaning it can only live in cave ecosystems and nowhere else. Because of complete darkness inside caves, the beetle has no eyes and relies on other senses. The specie's most characteristic features are the long "neck" (actually the thorax) and the swollen abdomen. It is endemic to the Dinaric Karst, being only found in parts of southwestern Slovenia, Croatia and the Trieste Karst in Italy.
Finding one inside a large cave is not an easy task as the beetle is roughly the size of a large ant! We were thus very relieved to find one, walking a cave wall, some 3 meters above the ground. Thanks to a good zoom, we managed some documentative shots of this rare animal.
Spot the beetle...
Narrow-necked Cave Beetle Leptodirus hochenwartii

Other animals were to be found in the cave, the most obvious being some hibernating Lesser Horshoe Bats Rhinolophus hipposideros. The cracks and crevices within the cave walls were hosting the two rather common species of cave Orthoptera: Cave Cricket Troglophilus cavicola and Neglected Cave Cricket Troglophilus neglectus. Another interesting and rather typical cave animal was the pigment-less Cave Woodlouse Titanethes albus. On the other hand, we didn't find any of the cave spiders, which are also typical for this enviroment and are completely blind.
Lesser Horshoe Bat Rhinolophus hipposideros
Cave Cricket Troglophilus cavicola
Neglected Cave Cricket Troglophilus neglectus
Cave Woodlouse Titanethes albus
Bone of a presumed cave animal (bear??).
Old inscription by an early cave explorer, dating back to 1863.

For more about the subject check the following links:
The underground world - on our WildSlovenia website
Karst Museum in Postojna 

Monday 18 November 2019

Slow November birding

Flamingo Phoenicopterus roseus, Škocjanski zatok NR.
The Zoo: White Stork Ciconia ciconia, White-fronted Geese Anser albifrons and Cattle Egret Bubulcus ibis with "boškarin" cattle, Škocjanski zatok NR.
A typical scene of Škocjanski zatok in the recent weeks.
Reed Bunting Emberiza schoeniclus, Škocjanski zatok NR.
Curlew Numenius arquata, Škocjanski zatok NR.
Sandwich Tern Sterna sandvicensis, Miramar (Trieste).
Cerknica lake filling with water.
Hen Harrier Circus cyaneus, Cerknica lake.
Grey-headed Woodpecker Picus canus, Cerknica lake.
Goshawk Accipiter gentilis, Karst edge.
Bullfinch Pyrrhula pyrrhula in our garden.
Green Woodpecker Picus viridis, Karst.
Trooping Funnel Clitocybe geotropa, Karst.
Oak woodland in autumn colours, Karst.
Smoke Bush Cotinus coggygria, Karst.

Short photo-post this time, due to lack of time, rainy weather, laziness and most of all... lack of wildlife - oh, it's November! Most of the recent birding has been either at work in Škocjanski zatok or in our garden in the Karst. There was nothing really special in particular, but rather some low-intensity seasonal birding. The highlight has been a Wallcreeper Tichodroma muraria, enjoyed during "working hours" along the Karst edge and a shy Ural Owl Strix uralensis in the forests by lake Cerknica. Other seasonal species included Northern Bullfinch Pyrrhula pyrrhula ssp. pyrrhula, Great Grey Shrike Lanius excubitor, Hen Harrier Circus cyaneus, Redwing Turdus iliacus and the local scarcities/rarities at Škocjanski zatok, featured in the above photos.
At this time of heavy rains and floods it is perhaps better to enjoy some typical geomorphological features of the Karst (karstic springs, swelling rivers, temporary lakes, roaring sinkholes ect.), rather than roving around aimlessly in search of wildlife.

Saturday 2 November 2019

Crane day & northern visitors

After the unusual spell of warm and sunny weather of the past weeks, now autumn (or winter?) is really upon us. The recent days have been amazingly cold and wintry due to the strong north-easterly burja wind blowing across western Slovenia. Many areas experienced the first sub-zero temperatures of the season and even the first snow in the mountains. Yesterday the skies cleared over much of Slovenia and the sunny, but cold weather unleashed the migration of Common Cranes Grus grus from the plains of Hungary. Apparently yesterday was THE day to be out and witness the large movements of these majestic migratory birds. Hundreds were reported from around Slovenia and we were also lucky to have chosen the right sites to go birding. Taking the weather into account, we headed for the Štajerska region to visit the country's migration hotspots near Maribor and Ptuj. By mid morning we were already watching a large flock of around 350-400 Cranes catching a thermal over the Medvedce reservoir and forming a "wedge" before flying west. Later we observed several other flocks, including around 50 over lake Ptuj, 12 near Pragersko and finally 80-100 low over the Medvedce reservoir in the evening. All in all we must have seen more than 500 Cranes, which is a rather good total for a day in Slovenia. Below is a video we recorded when the flocks were passing low - listen out for their loud and distinctive migration calls.
Common Cranes Grus grus
The Medvedce reservoir hosted a large flock of +1000 Greylag Geese Anser anser among which were also a few White-fronted Geese Anser albifrons. Two 1st winter Little Gulls Hydrocoloeus minutus were also of note for us, as we don't often observe this species in western Slovenia. A nice flock of migrating Lapwings Vanellus vanellus and the first Bittern Botaurus stellaris of the winter season were also good to see. 
Nearby, the large reservoir lake of Ptuj held good numbers of wildfowl, among which Tufted Duck Aythya fuligula and Pochard Aythya ferina were the commonest as usual. Among the early winter arrivals were 4 Goldeneyes Bucephala clangula and a Red-throated Diver Gavia stellata. A migrant Grey Plover Pluvialis squatarola, good numbers of Pygmy Cormorants Phalacrocorax pygmeus and several Goosanders Mergus merganser were also of note. However we were most happy when an adult White-tailed Eagle Haliaeetus albicilla, a rare breeder in Slovenia, glided above the lake. At the fishponds of Rače we observed another Little Gull Hydrocoloeus minutus and some Ferruginous Ducks Aythya nyroca, the latter having the largest Slovenian breeding population right in the Štajerska region. Other interesting birds at various sites were also Water Rail Rallus aquaticus, Crested Lark Galerida cristata, Great Grey Shrike Lanius excubitor and a White Stork Ciconia ciconia taking a nap on its old nest.
White-tailed Eagle Haliaeetus albicilla
Red-throated Diver Gavia stellata
Goldeneye Bucephala clangula
Tufted Ducks Aythya fuligula and Pochards Aythya ferina
Ferruginous Duck Aythya nyroca
Pygmy Cormorant Phalacrocorax pygmeus
White Stork Ciconia ciconia
The artificial lake of Ptuj on the river Drava with the town of Ptuj in the distance.

Last week's bird monitoring at Škocjanski zatok which took place during an overcast and misty autumn day was also quite productive in terms of migrants. The most interesting species was a beautiful male Northern Bullfinch Pyrrhula pyrrhula ssp. pyrrhula. This bird seemed a bit out of place at this coastal wetland and it was indeed a new species for the reserve. We identified the bird by its distinctive trumpeting call. Birds with such calls have a north-European or Siberian origin and are usually referred as "Trumpeting", "Komi" or "Northern" Bullfinches. Morphologically they are almost identical to "our" ordinary Bullfinches, except for they are slightly bigger and have colder colour tones. They are known to make irregular winter irruptions into continental Europe, including Slovenia. Apart from the bird at Škocjanski zatok we also observed/heard at least 4 other Northern Bullfinches this autumn, mostly in the Karst.
During the monitoring we had a large flock of finches containing many Bramblings Fringilla montifringilla, Linnets Linaria cannabina and Hawfinches Coccothraustes coccothraustes, feeding with Water Pipits Anthus spinoletta and Meadow Pipits Anthus pratensis on the wet meadows, while some Redwings Turdus iliacus were also in the hedges. A typical late-autumn migration scene. The freshwater part of the reserve also had a White-fronted Goose Anser albifrons and a migrant White Stork Ciconia ciconia, while the lagoon is still home to the lingering juvenile Flamingo Phoenicopterus roseus. A lonely Swallow Hirundo rustica was probably our last one for this year.
Northern Bullfinch Pyrrhula pyrrhula ssp. pyrrhula
Brambling Fringilla montifringilla
Brambling Fringilla montifringilla & Linnet Linaria cannabina
Water Pipit Anthus spinoletta
White Stork Ciconia ciconia
White-fronted Goose Anser albifrons