Winter Birding in Slovenia

Published by Surfbirds Admin (surfbirds AT

Participants: Dan Brown (Sunbird), Alex Lees (UEA), Simon Mahood (PIMP) Rob Martin (PUNK), Rich Moores (RBA)


By Alex Lees & Dan Brown

With the prospect of the "hardest winter birding in Europe" — owls, woodpeckers and gamebirds as an honourable challenge, five Norwich birders — Dan Brown (Sunbird), Alex Lees (UEA), Simon Mahood (PIMP) Rob Martin (PUNK) and Rich Moores (RBA) visited the country for four days in December 2004. Despite its considerable birding potential outlined at, a search at only generates six trip reports, one of which - Mahood (2003) stems from a visit by 2004 team members Brown and Mahood in June 2003. Four days did little to do the country and its avifauna justice and we were unsurprised to miss the likes of Tengmalm’s Owl (Aegolius funereus) and Rock Partridge (Alectoris graeca), but despite the brevity of the mission we were successful in finding some excellent sites and interesting birds detailed below.


Team members being arrested at Lubjuno — try to ensure your hire car is not Croatian when dazzling owls and farmers in the middle of the night…. (Copyright Dan Brown)


Lake Cerknica

Lake Cerknica is a temporary eutrophic late situated on the largest karst field in Slovenia, it is usually totally dry in summer and late winter, but encompasses an area of 2600 hectares when full in spring and autumn comprising huge expanses of reed sedge and wet grasslands. It is internationally important for breeding Corncrakes (Crex crex) when Little Bittern (Ixobrychus minutus), Ferruginous Duck (Aythya nyroca), Spotted (Porzana porzana) and Little Crakes (P. parva) and attracts passage Red-footed Falcons (Falco vespertinus) and White-winged Black terns (Chlidonias leucopterus) but its importance as a winter site is largely unrecognised (Birdlife International 2003, Grimmet & Jones 1989).


Lake Cerknica (Copyright Dan Brown)

Mount Nanos

An impressive limestone massif dominating the western skyline of the country. The plateaux rises dramatically and gives way to extensive grassland with stunted copses as well as an expansive forest stretching off to the north east. The site has no official protection and is obviously a popular hunting spot which makes locating the ultimate prize here - Rock Partridge (Alectoris graeca) very difficult. Alpine Accentor (Prunella collaris) and Snow Bunting (Plectrophenyx nivalis) may occur around the summit in winter whilst in spring and summer the area comes alive with the songs of Rock Thrush (Monticola saxatilis) and Rock Buntings (Emberiza cia).

Mount Nanos (Copyright Dan Brown)

Ljubno and Sava valley

A beautifully fresh alpine valley this area marks the southern end of the Julian Alps and provides some excellent birding. Although 30km long, almost the entire length may produce species of interest, however several sites deserve slightly more attention. In areas of old growth Pygmy Owls (Glaucidium passerinum), White-backed (Dendrocopos leucotos) and Three-toed Woodpeckers (Picoides tridactylus) may be found. Thicker understory often holds Hazel Grouse (Bonasa bonasia) — often an elusive species, however with enough time a likely score. Nutcrackers (Nucifraga caryocatactes) and Black Woodpeckers (Dryocopus martius) are common; however, the latter becomes noticeably more difficult in winter. On a par with Rock Partridge in terms of difficulty is Tengmalm’s Owl (Aegolius funereus). The best chance of this species seems to be around Luce and Dobravlje, however it is rare even here.

Sava Valley (Copyright Dan Brown)


Although not protected the area is heavily managed by hunters, primarily due to the income generated from large game hunting including Brown Bear (Ursus arctos), Wild Boar (Sus scrofa) and deer. This has lead to the protection of pristine areas of primeval beech and spruce forest along the ridge top to the west of the town. Here the commonest owl is Ural (Strix uralensis), whilst Three-toed Woodpeckers may be found by thorough searching of the dead spruces. White-backed Woodpecker occurs at lower densities but the site still offers probably the best chance of this species.


Kocevje (Copyright Dan Brown)

Annotated systematic list

Hazel Grouse Bonasa bonasia
The distinctive wing-whirs and alarm calls of this species were heard from the hills near Lubjuno, where DB & SM found this species in June 2003 (Mahood 2003).
Black-throated Diver Gavia arctica
At least 11 individuals were present on Lake Cerknica, this species winters widely across eutrophic lakes in Central Europe.
Great Egret Casmerodius albus
Three birds were present at Lake Cerknica, most probably from Neuiseedel in Austria or Balaton in Hungary (Tout 1995).
White-tailed Eagle Haliaeetus albicilla
One, possibly two adults and an immature were recorded at Lake Cerknica, these birds apparently use the site as a feeding/staging area year-round but do not breed (BirdLife International 2003). Cerknica also appeared to be a suitable site for wintering Spotted Eagles (Aquila clanga) but we did not locate any in our short stay.
Eurasian Pygmy Owl Glaucidium passerinum
We located at least three calling individuals in the hills above Lubjuno, one of which showed exceptionally well just after dawn.

Glaucidium passerinum Copyright Rob Martin

Ural Owl Strix uralensis
Slovenia holds an internationally important population of this impressive species. DB & SM previously successfully found this species along the ridge at Kocevje (Mahood 2003) — Urals are known to competitively exclude Tawny Owls (Strix aluco) from their preferred pre-montane forest (Vrezec & Tome 2004) and this appeared to be this case at Kocevje. We obtained unsatisfactory views of a furtive day-roosting bird mid slope, but despite much effort no calling individuals were located at night.
Grey-headed Woodpecker Picus canus
This species was easily located in floodplain forest at the foot of the slope at Kocevje.

Picus canus Copyright Rob Martin

Middle Spotted Woodpecker Dendrocopos medius
A single bird was located in the same area as the above.

Dendrocopus medius Copyright Rob Martin

White-backed Woodpecker Dendrocopos leucotos
What was almost certainly this species was glimpsed at Sava. Small populations of the Balkan race lilfordi have been located in virgin forest in central southern Slovenia in recent years and occasional dispersing birds of the nominate subspecies are seen in the north of the country (Tout 1995).
Three-toed Woodpecker Picoides tridactylus
Perhaps Europes most sought-after picid, the extensive virgin montane forests play host to a globally significant proportion of the alpinus subspecies which is endemic to the mountains of Central, Southern and South—Eastern Europe. Because of its dead wood dependence, Bütler et al (2004) considered this taxon to be effective indicator species for forest sites with a high value for other specialised species dependent on dead wood, many of which are red list species. We found at least one pair holding winter territory atop the forested ridge above the town of Kocevje.
Alpine Accentor Prunella collaris
At least three individuals were located wintering on the slopes at Nanos, favouring the rocky escarpment below the radio mast.
Great Grey Shrike Lanius excubitor
Two individuals were located on winter territory at Lake Cerknica and a third was seen by the motorway en route to the airport.
Spotted Nutcracker Nucifraga caryocatactes
We found this species easy to find at both Lubjuno and Sava.

Nucifraga caryocatactes Copyright Rob Martin

Snow Bunting Plectrophenax nivalis
A single individual was located feeding on the turf by the radio mast at Nanos, here at the southerly limit of the species wintering grounds.


BirdLife International 2003 BirdLife's online World Bird Database: the site for bird conservation. Version 2.0. Cambridge, UK: BirdLife International. Available:
Bütler, P., Angelstam, P., Ekelund, P & Schlaepfer, R. 2004 Dead wood threshold values for the three-toed woodpecker presence in boreal and sub-Alpine forest. Biological Conservation 119: 305—318
Grimmett, R.F.A. & T.A. Jones 1989. Important bird areas in Europe. ICBP Technical Publication No. 9, Cambridge.
Mahood, S. 2003 Slovenia, 4th-11th June 2003. Trip report online at: /mb/trips/slovenia-0703-v2.html
Tout, P. 1995. The Birds of the Northern Adriatic Region. online at:
Vrezec, A & Tome, D. 2004. Altitudinal segregation between Ural Owl Strix uralensis and Tawny Owl S. aluco: evidence for competitive exclusion in raptorial birds. Bird Study, Volume 51:264-269.

Trip List

Mute Swan Cygnus olor
Greylag Goose Anser anser
Tufted Duck Aythya fuligula
Common Goldeneye Bucephala clangula
Goosander Mergus merganser
Eurasian Wigeon Mareca penelope
Northern Shoveler Anas clypeata
Mallard Anas platyrhynchos
Common Teal Anas crecca
Hazel Grouse Bonasa bonasia (h)
Common Pheasant Phasianus colchicus
Black-throated Diver Gavia arctica
Little Grebe Tachybaptus ruficollis
Great Crested Grebe Podiceps cristatus
Great Egret Casmerodius albus
Grey Heron Ardea cinerea
White-tailed Eagle Haliaeetus albicilla
Western Marsh Harrier Circus aeruginosus
Hen Harrier Circus cyaneus
Eurasian Sparrowhawk Accipiter nisus
Common Buzzard Buteo buteo
Common Kestrel Falco tinnunculus
Common Moorhen Gallinula chloropus
Eurasian Coot Fulica atra
Northern Lapwing Vanellus vanellus
Eurasian Collared Dove Streptopelia decaocto
Eurasian Pygmy Owl Glaucidium passerinum
Tawny Owl Strix aluco
Ural Owl Strix uralensis
Common Kingfisher Alcedo atthis
Grey-headed Woodpecker Picus canus
Black Woodpecker Dryocopus martius (h)
Great Spotted Woodpecker Dendrocopos major
Middle Spotted Woodpecker Dendrocopos medius
White-backed Woodpecker Dendrocopos leucotos
Three-toed Woodpecker Picoides tridactylus
Water Pipit Anthus spinoletta
Grey Wagtail Motacilla cinerea
White-throated Dipper Cinclus cinclus
Winter Wren Troglodytes troglodytes
Dunnock Prunella modularis
Alpine Accentor Prunella collaris
European Robin Erithacus rubecula
Common Blackbird Turdus merula
Fieldfare Turdus pilaris
Redwing Turdus iliacus
Mistle Thrush Turdus viscivorus
Goldcrest Regulus regulus
Firecrest Regulus ignicapilla
Long-tailed Tit Aegithalos caudatus
Marsh Tit Parus palustris
Crested Tit Parus cristatus
Coal Tit Parus ater
Blue Tit Parus caeruleus
Great Tit Parus major
Eurasian Nuthatch Sitta europaea
Eurasian Treecreeper Certhia familiaris
Great Grey Shrike Lanius excubitor
Eurasian Jay Garrulus glandarius
Common Magpie Pica pica
Spotted Nutcracker Nucifraga caryocatactes
Western Jackdaw Corvus monedula
Hooded Crow Corvus cornix
Common Raven Corvus corax
House Sparrow Passer domesticus
Eurasian Tree Sparrow Passer montanus
Common Chaffinch Fringilla coelebs
Brambling Fringilla montifringilla
European Greenfinch Chloris chloris
European Goldfinch Carduelis carduelis
Eurasian Siskin Carduelis spinus
Common Crossbill Loxia curvirostra
Eurasian Bullfinch Pyrrhula pyrrhula
Hawfinch Coccothraustes coccothraustes
Snow Bunting Plectrophenax nivalis
Rock Bunting Emberiza cia

Alex Lees & Dan Brown 2005