Sunday 22 May 2022

Bearly May

Several weeks have passed since our last blog in early May. As you all probably already know, this is the busiest month of the year for us. However it is also our favourite one! Over the past weeks we have spent most of our working days in the field, doing bird censuses in various parts across Slovenia, but also abroad. The weather has been very favourable for this (dry, sunny, no wind), so we managed to pack a lot of field activities in a quite restricted amount of time. 

On the 14th of May we at DOPPS - BirdLife Slovenia organised an event about the Capercaillie Tetrao urogallus in the Julian Alps. It was aimed at sensibilizing the wider public about the conservation issues concerning this iconic species, as well as for promoting our ongoing campaign Guardians of Endangered Birds (Capercaillie is one of the campaign's target species). Before the main event and in the early hours of the morning, 51 experienced bird counters checked the presence of Capercaillie on 26 different locations within the Jelovica plateau in the Julian Alps. The species was confirmed on 24 locations, with 19 singing males recorded in total. Combined with other censuses of the species in the area, the estimate of occupied Capercaillie territories for 2022 on Jelovica is 29. For comparison, a similar count in 2011 revealed 49 males on leks. This translates as a 40% decline of the species (in this area alone) in eleven years. A quite sad result that confirms the ongoing decline of this iconic bird in Slovenia, while the causes are still not fully researched.

Nevertheless, I was lucky to confirm (at least) one Capercaillie on my plot. Although I didn't see the bird itself, but only heard it (pics below are from the archive), it was still amazing to wait for dawn in the forest and then be rewarded with the presence of this majestic bird. Later in the morning, after the dawn chorus, I checked my plot carefully to look for signs and found quite a lot of Capercaillie's droppings (cigars) which further confirmed the occupancy of this territory.

Waiting for dawn in the kingdom of the Capercaillie.
Capercaillie's habitat on the Jelovica plateau.
Lekking male Capercaillie Tetrao urogallus (pic from 2021, video).
Capercaillie's droppings - "cigars".
The mountain coniferous forest where I was counting Capercaillies is roughly above 1400 metres a.s.l. and provides some excellent habitat also for the Three-toed Woodpecker Picoides tridactylus. Indeed, first I came across a feeding female and later also a drumming male nearby. The mountain forests on high-karst plateaus such as Jelovica and Pokljuka represent the species' population stronghold in Slovenia. The same areas also hold the largest densities of Capercaillie and Hazel Grouse Bonasa bonasia in the country. Among other interesting birds on my plot I also heard a pair of Ural Owls Strix uralensis and several lekking Black Grouse Lyrurus tetrix, the calls of the latter coming from a nearby mountain pasture above the tree line.
Feeding trees of Three-toed Woodpecker Picoides tridactylus.
Three-toed Woodpecker Picoides tridactylus
In the early hours of the morning I also came across several Alpine Salamanders Salamandra atra posing perfectly on stumps and moss-covered rocks (I swear, I didn't put them there!). This interesting species of amphibian can be encountered with relative ease in the Slovenian mountains in wet or rainy weather. Inhabiting a karstic environment where surface water is rare, females don't deposit eggs, but give birth to live salamanders (viviparity). They are always a joy to find!
Alpine Salamander Salamandra atra
Black Slug Arion ater (is it?) feeding on a tasty mushroom.
While returning back to the car from my Capercaillie plot I came across several fresh footprints of Brown Bear Ursus arctos, as well as scats of Wolf Canis lupus. On the gravel road I also noticed some bear's droppings I didn't remember from earlier in the morning. They were very fresh and my thought was "oh, this bear must still be around". And indeed, after a few hundred metres of walking on the road, I stopped abruptly: a Brown Bear climbed from the forested slope on my left, right onto the road, some 30 metres away from me! Only a few seconds passed before the bear noticed me and started to run in the opposite direction, on the main road. There was not enough time for photos. As I knew two of my colleagues were further ahead the same road, I phoned them to tell a bear was running in their direction. As we were on the line, they saw the bear running towards them, but then leaving the road and disappearing into the forest. What an incredible way to round up a fantastic morning in the Alps!
Brown Bear's footprint.
Brown Bear's droppings.
The rear part of a Brown Bear Ursus arctos running away from me.
Now changing region, but still remaining in the forest. At the end of April and in the first half of May we were abroad for a few days, on two rounds of bird counts for our Croatian BirdLife colleagues. We needed to carry out some woodpecker & forest owls censuses in the Plitvice National Park (central Croatia). On this blog we don't usually report about trips outside of Slovenia, but in this case, given the habitat & species being basically the same as those in the Dinaric forests of Slovenia, we'll make an exception (the Dinaric mountains in Slovenia continue southwards throughout Croatia and as far south as Albania). The main species we censused were the two habitat specialists: White-backed Woodpecker Dendrocopos leucotos lilfordi & Three-toed Woodpecker Picoides tridactylus, as well as the commoner Grey-headed Woodpecker Picus canus. The habitat we worked included both commercial forest (mostly coniferous) and old-growth (primeval) mixed forest of beech Fagus sylvatica and silver fir Abies alba. We were very impressed by the extents and quality of old-growth forest, including huge amounts of dead wood and amazing diametres of trees. The habitat proved excellent for our specialists species, as we confirmed 4 territories of White-backed and 4 territories of Three-toed Woodpecker. However the night censuses of forest owls didn't reveal any Pygmy Glaucidium passerinum or Tengmalm's Owl Aegolius funereus, but at least an amazing number of Ural Owls Strix uralensis - we counted 14 individuals on one transect. During the second census in early May we also had some lovely Collared Flycatchers Ficedula albicollis holding territory in the old-growth forest.
Probably the largest silver fir Abies alba we've ever seen.
Large amounts of dead wood in the old-growth forest reserve within the park.
Watching a White-backed Woodpecker in the old-growth forest.
May greenery in the old-growth forest reserve.
Collared Flycatcher Ficedula albicollis
Playback census for woodpeckers in the commercial forest.
White-backed Woodpecker Dendrocopos leucotos lilfordi
Three-toed Woodpecker Picoides tridactylus
Common Treecreeper Certhia familiaris stealing some spider's prey.
Ural Owl Strix uralensis
Taking full advantage of local forms of cover in the old-growth forest.
Moschatel Adoxa moschatellina
Waldstein's Bittercress Cardamine waldsteinii
Kitaibel's Bittercress Cardamine kitaibelii (with late April snow).
Henbane Bell Scopolia carniolica
Beech Fagus sylvatica - young leaves.
Sycamore Acer pseudoplatanus - new leaves & flowers.
Norway Spruce Picea abies - flowers producing huge clouds of pollen in early May.
A few hundred kilometres north and we are back in the Dinaric forests of southern Slovenia. Like in April, also in May we spent a lot of time in the forests of Snežnik and in the Javorniki mountains, studying our White-backed Woodpeckers Dendrocopos leucotos lilfordi. With the awakening of spring and beech trees finally leafing in May, also life finally returns to these higher-altitude and cold forests. Large carnivores seem bo te somehow easier to see in this season, as they are more actively looking for food even during the day. Therefore encounters with Slovenia's most iconic animal, the Brown Bear Ursus arctos somehow become more probable. I was quite surprised to see my first bear of the season while driving on the main forest road through Snežnik. The young male was feeding on fresh grass at the side of the tarmac, when I drove by. It wasn't too scared by the presence of a car and for a while it calmly continued to eat, before slowly moving down from the road and into the forest.
Brown Bear Ursus arctos (young male) feeding by the main road through Snežnik.
Only some days later I had the most bear-packed day of my life! The morning started already well, when driving to a White-backed Woodpecker site, I spotted an adult female moving slowly in the forest some 70 metres from a gravel road. When I stopped the car and observed her, I noticed she also had three little cubs following her! On their slow way to cover in some thick conifers, they posed well a couple of times, before disappearing. Later in the morning, in another area I was standing by a tree, listening for White-backs, when suddenly, another mother bear, this time with one cub, walked by, about hundred metres away from me. Then, in the afternoon I was on the opposite site of the Snežnik plateau and was walking a remote rocky area of old-growth forest, when I heard some loud and unusual moans. They reminded me some odd Red Deer ruts, but they were shorter and in a different tone. Only later at home, when checking some bear vocalisation, I realised what I heard was indeed the moan of a Brown Bear! To round up the bear day nicely, when driving back home from the forest, I spotted yet another bear crossing the road some hundred metres in front of the car. This rose my day total to 8 different Brown Bears!!
Brown Bear Ursus arctos, adult female.
Brown Bear Ursus arctos - one of the 3 cubs.
Brown Bear cubs following their mother deep into the forest.
Brown Bear's signs are everywhere on Snežnik!
Fox Vulpes vulpes
White-backed Woodpecker Dendrocopos leucotos lilfordi, male collecting food.
Red Squirrel Sciurus vulgaris
Mount Snežnik (1796 m) from its eastern slopes.
Beech trees above 1400 m a.s.l. were still leafless in mid May...
...while lower down (1300-1400 m a.s.l.) they were just beginning to sprout leaves.
Blue-eyed Mary Omphalodes verna
Swarms of tiny flies were covering the skies of the forest in the warm days of mid May.
Dinaric beech-silver fir forest (Omphalodo-Fagetum) on Snežnik plateau.
Centenary beech Fagus sylvatica contorted by the wind and snow.
The beginning of spring life in the mountain beech forests.
Old-growth forest reserve on Snežnik plateau.
Rocky areas in the Dinaric mountains are ideal places to look for reptiles. At lower altitudes and on sunny slopes, limestone screes provide habitat for the iconic Nose-horned Viper Vipera ammodytes. However, rocky areas in shadier and cooler places at higher elevations are home of the Adder Vipera berus. This snake is typically seen on the summit of mount Snežnik, hiding in the rocks among the mountain pines Pinus mugo, where melanistic (completely black) specimen are not unusual. However it can be also found lower down, sometimes in small forest clearings. In one such spot I came across a handsome male of the bosniensis subspecies. It was calm and moving quite slowly, so I had time to watch & photograph it for several long minutes - watch the video.
Habitat of Adder Vipera berus
Adder Vipera berus ssp. bosniensis
In the mid hours of the day birdlife in the forest becomes quiet, so it's a good idea to move out on the limestone grasslands at the south-western edge of Snežnik's plateau. During a lunch break on the top of a small rocky hill I had the chance to observe an interesting mix of large soaring birds. The local adult Golden Eagle Aquila chrysaetos was putting on a good show above my head, as was a Short-toed Eagle Circaetus gallicus hunting reptiles above the limestone screes, while later I also spotted a Black Stork Ciconia nigra soaring above the plateau's edge. These grasslands are also the home of Skylark Alauda arvensis, Tree Pipit Anthus trivialis, Rock Bunting Emberiza cia, but also much rarer birds such as Rock Thrush Monticola saxatilis and the now almost-extinct Rock Partridge Alectoris graeca.
Limestone grasslands at the edge of the forest on Snežnik's plateau.
Trieste Gentian Gentiana tergestina, some were still in flower.
Scanning the horizon for raptors.
Golden Eagle Aquila chrysaetos
The vast grasslands are maintained by extensive grazing of sheep.
A bachelor herd of Red Deer Cervus elaphus grazing the grasslands in the evening.
A few hundred metres down, in the Karst's oak woodlands, leafing took place already in early May and the canopies are now completely "closed". Woodlands look like jungles and it's very difficult to spot any birds at all. Just before the main leafing, we carried out our last rounds of spring censuses. Middle Spotted Woodpeckers Leiopicus medius were breeding in the known territories, however, due to lack of time this year we didn't manage to find any nests. Our local Ural Owls Strix uralensis seem to be still around, although apparently they won't be breeding this year, due to lack of rodents in the forest (after last year's super productivity). One morning while doing a transect, we flushed a poor Ural Owl from a puddle, where it was making a morning bath. The wet and muddy bird flew up a tree nearby and started to preen in front of us. When we checked the puddle, we even found its footprint in the mud.
Sessile Oak Quercus petraea - fresh leaves & flowers.
Muddy Ural Owl Strix uralensis after the morning bath.
Puddle where the Ural Owl had a bath.
Ural Owl's footprint in the mud.
Birding in the Karst's oak-beech woodlands is tough in late spring.

Among the many woodland flowers now already at the end of their blooming season are the impressive peonies. Paeonia officinalis is the common one throughout the Karst, liking warm, sunny woodland & scrub, whereas Paeonia daurica (until recently thought to be P. mascula) grows in shadier places and is much rarer. Both have very large flowers, the largest among any Slovenian plant and are typical Asian/steppe species of the European flora. In Slovenia peonies are only found in the warmer, sub-Mediterranean part of the country (S & SW).
The very common Paeonia officinalis
The rarer Paeonia daurica (though to be P. mascula), loving shadier places.

After a long time this weekend we also guided two foreign guests on a birding trip. Although we are now mostly occupied with other work, we might occasionally still guide short day tours around Slovenia. May is perfect for a visit to the lake of Cerknica (Cerkniško jezero), so that's where we took our two guests from the US. The temperatures were very high and it felt like summer, so birding was quite tought at times. However we managed to find several interesting species, especially in the wet meadows around the lake. All in their typical breeding habitat we observed: two male Common Rosefinches Carpodacus erythrinus, lots of Yellow Wagtails Motacilla flava, Whinchats Saxicola rubetra, Marsh Acrocephalus palustris and Sedge Warblers Acrocephalus schoenobaenus, as well as several Golden Orioles Oriolus oriolus and Red-backed Shrikes Lanius collurio. The highlight however was a Lesser Grey Shrike Lanius minor, one of the rarest breeding birds in Slovenia (only a handful of breeding pairs in the last years). Among the later migrants there were 15 Red-footed Falcons Falco vespertinus and a mixed flock of 7 Little Gulls Hydrocoloeus minutus and 7 Whiskered Terns Chlidonias hybrida.
In the wet meadows of Cerkniško jezero.
Common Rosefinch Carpodacus erythrinus
Lesser Grey Shrike Lanius minor
White Stork Ciconia ciconia
The lake was almost completely dry.
Great Crested Grebe Podiceps cristatus
Pochard Aythya ferina
"Tall Violet" Viola elatior
Broad-leaved Marsh Orchid Dactylorhiza majalis


Although this post has been already quite long, we've been actually doing a lot more lately. A special chapter of its own are the bird surveys on the Karst's dry limestone grasslands. But that would be too much to add here, so stay tuned for the next post concentrating on the biodiversity of meadows & grasslands! Here's only an appetizer...

Red-backed Shrike Lanius collurio with spider.