Tuesday 31 March 2020

Springtime excitement

Spring is a busy period for us field biologists and the new season is just kicking in. On Sunday we went to monitor the rare White-backed Woodpecker Dendrocopos leucotos in the Javorniki mountains. We repeated last year's very successful census (when we discovered 7-8 White-backs). This year we "only" found 4 birds, including two drumming spontaneously and a rather silent pair. The beech forest habitat where the species lives has been heavily exploited by the timber industry in the last months. Probably because of this, several points were without White-backs. Nevertheless we enjoyed in the sight and sound of this territorial male:
Male White-backed Woodpecker Dendrocopos leucotos, Javorniki Mts.
Calling female White-backed Woodpecker Dendrocopos leucotos, Javorniki Mts.
Heavy logging machinery in the middle of a White-backed Woodpecker's territory.
Nearby also a pair of Ural Owls used to breed.

When we were about to finish the census our colleagues Mitja and Katarina Denac alerted us that earlier in the morning they found a Dotterel Charadrius morinellus in a karstic meadow near Divača. As the place was on our way back home, we gave it a try. After scanning the fields we soon found the bird, although it was very distant. So we approached and after some minutes could enjoy the bird at close quarters. Dotterel is a regular but rare and difficult-to-see migrant in Slovenia. As it breeds in the arctic tundra, it usually chooses open grassland and rocky areas as stopover sites. Luck is always needed with this particular species: the bird might be present one day, but vanishes overnight, therefore twitching isn't always an option. Although there are some traditional stopover sites, these need to be worked on a daily basis to guarantee success. Only a few Dotterels are observed in Slovenia every season, with most observations in early autumn, while spring sightings are fewer. With this species we were only lucky twice before (see here), both times on on mount Vremščica.
Dotterel Charadrius morinellus, Divača
(Huge thanks to Mitja and Katarina!).

Meanwhile other migrants are also returning from Africa. Recently we had several exciting season's firsts like: Short-toed Eagle Circaetus gallicus (2), Wryneck Jynx torquilla, Northern Wheatear Oenanthe oenanthe and Blue Rock Thrush Monticola solitarius in the Karst as well as Yellow Wagtail Motacilla flava, Alpine Swift Apus melba and White Stork Ciconia ciconia at Škocjanski zatok NR. There's also a good north-eastward passage of Marsh Harriers Circus aeruginosus, while the occasional Swallow Hirundo rustica and House Martin Delichon urbicum flying overhead always cheers us up. On the other hand there are still typical winter guests around like small flocks of Redwings Turdus iliacus roaming the karstic woodlands or the 40 or so Hawfinches Coccothraustes coccothraustes mixed with Siskins Spinus spinus still feasting on sunflower seeds in our garden.
Short-toed Eagle Circaetus gallicus, Karst.
Wryneck Jynx torquilla, Karst.
Northern Wheatear Oenanthe oenanthe, Karst.
Hawfinch Coccothraustes coccothraustes in the garden, Karst.

During an afternoon walk we investigated some excellent areas of oak and beech forest on the eastern edge of the Karst and counted no less than 8 (spontaneous) territorial Middle Spotted Woodpeckers Dendrocopos medius. This observation is extremely interesting because the area was already included in an acoustic census of the species back in 2016 and no Middle Spots were recorded there. A similar fact has been noted in several other sites around the Karst, suggesting a very recent colonisation of these areas by the species. Moreover last week a colleague confirmed 3 new territories in a woodland near Nova Gorica (an absolutely new site). Middle Spotted Woodpecker in western Slovenia is indeed becoming commoner year after year.
Middle Spotted Woodpecker Dendrocopos medius, Karst/Vipava valley.

As expected, at the moment there's also plenty of wildflowers to enjoy. New spring species come into bloom one after the other, especially on the dry karstic meadows, where the real show has yet to begin. One interesting habitat in early spring are the karstic dolinas - depressions formed by the erosion of limestone, commonly found all over the Karst. Some of these dolinas are very large and have steep limestone cliffs, where alpine species of plants such as Bear's Ear Primula auricula grow as ice age relicts. Last week we also visited some famous "Mediterranean islands" - limestone blocks in the otherwise sandstone Dragonja valley (in Slovenian Istria), where very rare Mediterranean species grow. These species are actually rare on a Slovenian level, but otherwise commonly found in other Mediterranean region; here they reach their northern edge of distribution. One such example is the beautiful Broad-leaved Anemone Anemone hortensis - absolutely stunning at this time of year! Other good wildlife seen recently include Dalmatian Algyroides Algyroides nigropunctatus and Nettle-tree Butterfly Libythea celtis, as well as many other butterflies.
Bear's Ear Primula auricula, Karst.
Mountain Pasqueflower Pulsatilla montana, Karst.
"Southern Lungwort" Pulmonaria australis, Karst.
Cornelian Cherry Cornus mas, Karst.
Bumblebee on Drooping Bittercress Cardamine enneaphyllos, Karst.
Dog's-tooth Violet Erythronium dens-canis, Karst.
Mezereon Daphne mezereum, Karst.
Nettle-tree Butterfly Libythea celtis, Karst.
Small Copper Lycaena phlaeas, Dragonja valley.
Dalmatian Algyroides Algyroides nigropunctatus, Karst.
Oil Beetle Meloe sp., Karst.
Limestone cliffs in the Dragonja valley.
Broad-leaved Anemone Anemone hortensis, Dragonja valley.
Wet cliffs by the river Dragonja with Maidenhair Fern Adiantum capillus-veneris.
Black Spleenwort Asplenium adiantum-nigrum, Dragonja valley.
Ground Pine Ajuga chamaepitys, Dragonja valley.
Prickly Juniper Juniperus oxycedrus, Dragonja valley.
Early Spider Orchid Ophrys sphegodes, Dragonja valley.