Spring in Karst & Istria

In the last few weeks we've been quite busy with various fieldwork, but were of course happy to spend a lot of our "working time" outdoors. Spring is now really in its full splendor: woodlands are lush green, flowers bloom everywhere and many of the "classical" summer migrants (birds) have already returned. We had different censuses to carry on, both in the Karst (on dry grassland) and in the Slovenian Istria (farmland areas), as well as the regular work at Škocjanski zatok NR.

In the Karst the iconic migrants like Cuckoo Cuculus canorus, Hoopoe Upupa epops, Wryneck Jynx torquilla and Scops Owl Otus scops are all back. A few days ago we observed again our local pair of Short-toed Eagles Circaetus gallicus, as well as a migrant Black Kite Milvus migrans (a rather scarce bird in Slovenia) and the first returning Red-footed Falcon Falco vespertinus.
Among butterflies certainly the Southern Festoon Zerynthia polyxena steals the show, although many other species are available at the moment, including the first Green Hairstreaks Callophrys rubi and Weaver's Fritillaries Boloria (Clossiana) dia.

Wryneck Jynx torquilla

Southern Festoon Zerynthia polyxena

Green Hairstreak Callophrys rubi

Weaver's Fritillaries Boloria (Clossiana) dia

Flowers now dominate the scene; mostly on open meadows, although some interesting species can still be found in the now increasingly shadier forests. In a small woodland near Divača we came across a group of ten Pale-flowered Orchids Orchis pallens in fine bloom. This is a rather scarce and localised species in Slovenia that favours light woodland and is among the first orchids to emerge in spring.

Pale-flowered Orchid Orchis pallens

In the forest, woodpecker activity has somehow slowed down as most of the birds are now incubating. However we are still following the breeding of Black Woodpecker Dryocopus martius and Middle Spotted Woodpecker Dendrocopos medius close to home. This year we also decided to follow the movements of a local pair of Black Storks Ciconia nigra (a very rare breeder in western Slovenia) in the hope of finding a nest and confirm the breeding. So far we have observed the pair a few times, but we still need to narrow down our research.

Black Woodpecker Dryocopus martius

Beech Fagus sylvatica

Forests turning green.

Monitoring the Black Stork Ciconia nigra.

The karstic flora on dry grasslands is now dominated by the blue and yellow colours of Globularias and different Fabaceae, plus the purple spots of Green-winged Orchids Anacamptis morio - the commonest orchid of all. Some grazed/mowed meadows in the Karst are so full with wildflowers that is hard to walk on them without trampling on the orchids! Among the most interesting species at the moment there's also the scarce Slender-leaved Fritillary Fritillaria orientalis (in Slovenia only found in the Karst) as well as carpets of Poet's Narcissus Narcissus poeticus.

A bird census earlier last week, on some dry limestone grasslands also produced 4 Tawny Pipits Anthus campestris (a rare and localised breeding bird in Slovenia), along the commoner, but fast-declining Skylarks Alauda arvensis and Linnets Carduelis cannabina. 

Slender-leaved Fritillary Fritillaria orientalis

Common Globularia Globularia punctata & Green-winged Orchid Anacamptis morio

Common Globularia Globularia punctata

Green-winged Orchid Anacamptis morio

Poet's Narcissus Narcissus poeticus subsp. radiiflorus

Spring pasture in the Karst.

Tawny Pipit Anthus campestris

Skylark Alauda arvensis

Dry karstic grassland in SW Slovenia with Trieste in the background.

Some days ago we also made a quick afternoon excursion to the "High Karst" of the Javorniki mountains. Given the limited amount of time spent there we were very successfull as we heard & observed two spontaneous-drumming White-backed Woodpeckers Dendrocopos leucotos, close to the place where we carried out the species' census two weeks ago. In the evening we also heard singing Tengmalm's Owl Aegolius funereus and Pygmy Owl Glaucidium passerinum, as well as observed/heard up to 5 Ural Owls Strix uralensis.

Ural Owl Strix uralensis

Recently quite a lot of time was also spent in Istria, around the Slovene coast. Istria has a sub-Mediterranean climate and spring there is usually well in advance if compared to the rest of Slovenia. During a bird census in the farmland areas of Sečovlje and Strunjan we enjoyed several interesting birds, as well as plants and butterflies. Two migrant Hoopoes Upupa epops were feeding on a grass-covered path and showed pretty well for quite a while. Up to 12 singing Wrynecks Jynx torquilla were also nice to hear & see, as well as several Nightingales Luscinia megarhynchos, a Zitting Cisticola Cisticola juncidis, a Purple Heron Ardea purpurea and several Sardinian Warblers Sylvia melanocephala, not to mention the tens of Cirl Buntings Emberiza cirlus and Corn Buntings Emberiza calandra. 

Hoopoe Upupa epops

Wryneck Jynx torquilla

Sardinian Warbler Sylvia melanocephala

Nightingale Luscinia megarhynchos

Corn Bunting Emberiza calandra pretending to be a Reed Bunting E. schoeniclus!

House Martins Delichon urbicum collecting mud for the nests.

Among plants, the highlight at Sečovlje was the very rare Roman Hyacinth Bellevalia romana, a Mediterranean species known to grow at just a few sites in Slovenia. The woodland edges were already full of Lady Orchids Orchis purpurea, while among butterflies the most interesting find was the beautiful Green-underside Blue Glaucopsyche alexis, typical of this time of the year. Later we also recorded the latter in our garden.

Roman Hyacinth Bellevalia romana

Lady Orchid Orchis purpurea

Green-underside Blue Glaucopsyche alexis

Fresh leaves of Downy Oak Quercus pubescens

Meanwhile spring migration is kicking in at Škocjanski zatok NR too, with lots of migrants around in the past week. Among the most interesting observation are certainly 2 Red-rumped Swallows Cecropis daurica (rare migrant), 1 Whimbrel Numenius phaeopus (scarce migrant), 2 Avocets Recurvirostra avosetta (scarce visitor at the reserve), 1 Spoonbill Platalea leucorodia, 2 Little Crakes Porzana parva and up to 4 Purple Herons Ardea purpurea (one pair bred at the reserve for 2 consecutive years... fingers crossed!). Common Terns Sterna hirundo have also returned in good numbers like every year and are preparing to nest at their colony in the lagoon. 

Avocet Recurvirostra avosetta

Purple Heron Ardea purpurea

Little Crake Porzana parva

Ashy-headed Wagtail Motacilla flava cinereocapilla

Common Tern Sterna hirundo

White-backed Woodpeckers

After about a month of unfavourable weather conditions (either strong wind or long-lasting snow cover), today we finally managed to carry out our census trasect for the White-backed Woodpecker Dendrocopos leucotos in the Javorniki mountains. The census is coordinated by DOPPS-BirdLife Slovenia and is one of the many yearly monitorings that targets important bird species within the Natura 2000 areas. White-backed ranks among one of the rarest woodpeckers, both in Slovenia and Europe. There are just about 150 breeding pairs in our country and the species is heavily threatened by intensive commercial logging. White-backed is a specialist woodpecker of old broadleaved forests, relying on large amounts of dead wood. A high biomass of dead and decaying broadleaved timber (mostly beech Fagus sylvatica) is essential in its habitat. Here it can find its main food - wood-boring beetle's larvae. Old beech forests that can support this woodpecker are rare and hence, the woodpecker itself is rare too.

Despite some bitter results from previous similar censuses earlier this year, today our transect was an enormous success. We were expecting perhaps a White-backed or two along our 15-points transect, but instead we were surprised by a staggering 7-8 individuals! Two were the already-formed pairs, while the rest were territorial males, coming to inspect us as we blasted their drummings with a playback (a scientific census is the only occasion when the use of a lure is justified). The lonely males showed all pretty well, even drumming back in front of us, while the pairs apparently had other matters on their minds and quickly vanished, after checking us first. We had plenty of opportunities for taking photos and record videos, although the light was terrible most of the time:

White-backed Woodpecker Dendrocopos leucotos - all males except for the last pic.

White-backed Woodpecker Dendrocopos leucotos - collage of drumming males.

Dead beech Fagus sylvatica trees in the White-backs habitat.

The forest was otherwise rather quiet, apart from a pair of Ural Owls Strix uralensis that we found by accident (as it frequently happens), a Grey-headed Woodpecker Picus canus calling and a probable Three-toed Woodpecker Picoides tridactylus only heard drumming in the distance. The woodland floor in the beech forest was covered by wonderful and smelly leaves of Ramsons (or Wild Garlic) Allium ursinum, as well as the first flowers of Blue-eyed Mary Omphalodes verna. The latter is a typical spring flower of the Dinaric forests (forming the association Omphalodo-Fagetum).

Ramsons Allium ursinum, not grass!

Blue-eyed Mary Omphalodes verna

Mount Nanos in the distance.

Karstic fantastic

Spring is now advancing fast and the changes in nature become increasingly visible. Trees are turning to beautiful light green colours, especially in areas close to the coast, where some oak woodlands already sport their full canopies. Meanwhile meadows and grasslands offer the season's first flowers to enjoy. As the post's title tells, we've been mostly around the Karst in recent days (as well as Škocjanski zatok NR), both for work and leisure. Last week we carried out the last transects of our census of Middle Spotted Woodpecker Dendrocopos medius and found an additional 14 territorial birds (about 10 pairs) - mostly in new areas of the Karst and Brkini. This year we had some amazing results and a rather steep increase in woodpecker numbers, compared to a few years ago. The species in western Slovenia isn't rare anymore, as it used to be until recently. Moreover Middle Spotted Woodpeckers have also been confirmed in the Trieste Karst by Italian ornithologists, with several territories occupied and nesting & copulation observed. These represent the first breeding records for the species in northern Italy.

Middle Spotted Woodpecker Dendrocopos medius

Typical Middle Spotted Woodpecker's habitat in the Karst.

Black Woodpecker Dryocopus martius

During a census we were once again caught completely by surprise by a stunning Ural Owl Strix uralensis, this time perched a few meters away from a forest road we were driving on. Given the increase in sightings in recent times, we should start to consider the species as a new potential breeding bird in large forest complexes in western Slovenia (Brkini hills, some parts of the Karst). Further investigation is certainly needed.

Ural Owl Strix uralensis

Last week the first Short-toed Eagles Circaetus gallicus have also returned from Africa. This rare eagle is mostly found in the western part of Slovenia, where it usually breeds on black pines Pinus nigra and hunts for reptiles over dry stony grasslands. Yesterday we observed a male returning to its last year's nesting site, not far from Sežana. About 10 days ago we also observed year's first Black Stork Ciconia nigra, not far from the village of Razdrto, where repeated observations in the last summers might suggest a possible breeding nearby.

Short-toed Eagle Circaetus gallicus

During the weekend we also visited the limestone cliffs along the Karst edge and had some interesting wildlife there as well. A beautiful male Wallcreeper Tichodroma muraria in breeding plumage was the highlight (if we exclude this). However the species doesn't breed in the Karst, but only overwinters and will soon head back to its Alpine breeding grounds. The cliffs were full of life as flocks of House Martins Delichon urbicum and Crag Martins Ptyonoprogne rupestris wheeled overhead, checking last year's nests in the overhangs. Also Alpine Swifts Apus melba have returned in numbers, while the cliff's chorus was produced by two singing Blue Rock Thrushes Monticola solitarius, several Rock Buntings Emberiza cia and Black Redstarts Phoenicurus ochruros. A nice pair of Peregrines Falco peregrinus was observed on the cliffs as well, where it probably nests. There were already many butterfly species around, but two in particular were of note: Nettle-tree Butterfly Libythea celtis, a very common sight around Nettle-trees Celtis australis and Southern Comma Polygonia egea, a rare species in Slovenia, restricted to the extreme south-west of the country. Among plants we cannot skip mentioning the endangered and endemic Tommasini's Sandwort Moehringia tommasinii (see here), in full bloom on the limestone cliffs.

Wallcreeper Tichodroma muraria

Nettle-tree Butterfly Libythea celtis

Southern Comma Polygonia egea

Hummingbird Hawk-moth Macroglossum stellatarum

Scorpion Senna Coronilla emerus subsp. emeroides (also Emerus major)

Tommasini's Sandwort Moehringia tommasinii

Dry karstic grasslands are also coming alive with the first flowers of the season, including the rather common, but always beautiful Mountain Pasqueflowers Pulsatilla montana, as well as the yellow cushions of Tommasini's Cinquefoil Potentilla tommasiniana. Certainly rarer is the Trieste Gentian Gentiana verna subsp. tergestina, an Illyrian endemic that got its name from the city of Trieste, where it was first discovered. Meanwhile the typical karstic dolines (depressions in the ground, with cooler climate) are hosting the greatest spectacle of early spring flowers. Apart from colourful carpets of common forest species in such places one can observe the odd Toothwort Lathraea squamaria. The shady cliffs at the edges of some dolines are also home to Bear's Ears or Auriculas Primula auricula, which live as ice age relicts, out of their normal range of distribution in the Alps. The most interesting butterfly on dry karstic meadows at this time of year is certainly the beautiful Southern Festoon Zerynthia polyxena. Yesterday we were lucky to add this species to our garden butterfly list!

Mountain Pasqueflower Pulsatilla montana

Trieste Gentian Gentiana verna subsp. tergestina

Tommasini's Cinquefoil Potentilla tommasiniana

Common Globularia Globularia punctata

Toothwort Lathraea squamaria

Dog's-tooth Violet Erythronium dens-canis & Hacquetia Hacquetia epipactis

Bulbous Corydalis Corydalis cava

Bear's Ear Primula auricula

Southern Festoon Zerynthia polyxena

During the last few days Škocjanski zatok NR also hosted some welcome spring arrivals, including: Common Swift Apus apus, Sand Martin Riparia riparia, Wryneck Jynx torquilla, Lesser Whitethroat Sylvia curruca, Northern Wheatear Oenanthe oenanthe and Moustached Warbler Acrocephalus melanopogon. More to come in the next days. Keep checking the reserve's page for regular updates.