Sunday 30 April 2017

Middle Spotted Woodpecker nesting in the Karst!

After the return from the Danube delta we can now enjoy in our favourite environment: the forest! This time of year is particularly busy for the woodland inhabitants, especially woodpeckers. In this post we'd like to share some exciting moments we've witnessed recently at our local patch on the Slovenian Karst, just a few minutes drive from our home.
Since 2015 we've been working on the occurrence of Middle Spotted Woodpeckers Dendrocopos medius in the Karstic region and right now a paper on the species is about to be published. In the last years, we carried out censuses in suitable karstic woods, where this rare oak-tree specialist might be present (see here & here). So far we have only found probable signs of nesting... until a few days ago, when we finally confirmed the nesting of this species in the Karst with the most obvious sign: an active nest-hole!
The activity in and around the nest is frantic, with the parents going in and out of the hole, delivering beakfulls of caterpillars to their chicks...
Despite being an oak-tree specialist, Middle Spotted Woodpecker doesn't always excavate nest-holes in oak, but prefers other soft-wood trees. In fact the choice of a nesting tree is dictated mainly by the state of wood decay, rather than the actual tree species. Having a quite weak bill, Middle Spotted likes to excavate in rotten wood, frequently close to some tree fungi (like Polypores), where the timber is even softer. 
In our case, the nest is located on a rotten branch of a beech Fagus sylvatica in a woodland of sessile oaks Quercus petraea. The hole is about 4-5 meters above the ground. In the first photo below two other larger holes are visible - those most probably belonged to Great Spotted Woodpecker.
In the next photos, note the characteristic erected red feathers on the head of the male (first two pics). Males have brighter crown feathers than females and when erected, they tend to be more conspicuous. The head colour can be easily compared when seeing both sexes together, such in the case of a nesting pair. Moreover when males approach the nest, they tend to erect the crown feathers as a sign of display. If you compare the sexes in all the photos, you will see that the female tends to have a more "gentle" look and not so bright red crown feathers. Note also the facial expression of the bird looking out from the hole (3rd photo below) - it is quite unlike any other woodpecker as it lacks moustachial stripes and the face looks quite plain.
When observing the nesting pair we payed attention not to disturb them and watched from a safe distance. Nevertheless the pair seemed very concentrated in bringing the greatest possible amount of food to the chicks and didn't bother our presence (short VIDEO). Middle Spotted Woodpeckers find their food mostly by gleaning and search the oak bark for small invertebrates and their larvae. At this time of year the main food brought to the chicks are caterpillars found in the tree canopies, but also other small insects (see pics below). In this respect Middle Spots are a bit like Blue Tits Cyanistes caeruleus or other Parus species that need to coincide their breeding with the greatest prey availability - that is, when the new green leaves are full of caterpillars.
The frentic activity of feeding the chicks should continue for at least a week, so we'll keep checking the status of the brood in the coming days.
Meanwhile the forest around the nest is alive with many other species. A Grey-headed Woodpecker Picus canus is "disturbing" the Middle Spots, drumming a few meters away from their tree and a Black Woodpecker Dryocopus martius should also be nesting somewhere in the same wood, together with a pair of Green Woodpeckers Picus viridis. And two more occupied cavities were found not far away...
A female Lesser Spotted Woodpecker Dendrocopos minor is looking out of her nesting hole. Note the tiny beak of the species, not really woodpecker-like. In fact its feeding technique is more similar to that of tit Parus species rather than that of other woodpeckers. But despite this, Lesser Spots still need to build the nest to rise up the chicks and usually every year a new hole is excavated.

Great Spotted Woodpecker Dendrocopos major has a more poweful beak and usually excavates several new nesting holes every year. Here it chose to do so in a rotten beech Fagus sylvatica - such trees have softer wood and in general are preferred by most woodpeckers.

The Karst's woodlands now also resound with the trills of migrating Wood Warblers Phylloscopus sibilatrix and with the songs of Cuckoos Cuculus canorus, while on the ground, some amazing flowers are in full bloom...
Paeonia officinalis with flowers as large as fists!
Rhagium mordax (Cerambycidae) feeding on Paeonia's nectar.
Ophrys insectifera - rather rare on the Karst, but we have it "in the backyard"!
Cephalanthera longifolia - a common woodland orchid.
Orchis purpurea - like woodland edges and sunny open woods.

At the end a note is necessary: all the above woodpecker's holes were found exclusively by Sara, whose primary interest this spring seems to be nest-hole finding! ;-)

Friday 21 April 2017

Forest specialists: White-back & Three-toe

Some days ago, while looking for Three-toed Woodpeckers in the mixed forests of Javorniki mountains we stumbled upon this female White-backed Woodpecker Dendrocopos leucotos (ssp. lilfordi). We watched it for at least one hour during which it was observed repeatedly drumming and even excavating a nest-hole in a rotten beech Fagus sylvatica. From a distance we could also hear a second bird drumming...perhaps its mate? VIDEO (watch HD and listen out for the drumming). White-back is one of Slovenia's rarest breeding birds (estimated 100-150 pairs) and any nesting pair is potentially interesting. The species has a quite narrow ecological niche, being a broadleaved forest specialist, inhabiting only natural or semi-natural forests with large amounts of dead timber where it finds its main food (wood-boring beetle larvae). Thus it is nowadays rare over much of Europe. 
Habitat where the White-backed Woodpecker was found: a mixed Dinaric forest of beech Fagus sylvatica and silver fir Abies alba, with elements of Norway spruce Picea abies, on a steep hill (around 1000 above sea level) in the Javorniki mountains.
Fomes fomentarius - a common fungus in Slovenia's forests, usually found on beech Fagus sylvatica or other broadleaved trees.
Later on we were at last successful in our search as we found this stunning male Three-toed Woodpecker Picoides tridactylus (ssp. alpinus) feeding very close to the road on a dead silver fir Abies alba. As usual with this species, the bird proved very cooperative and allowed very close views, without any sign of fear. It even moved towards us a few times and wasn't even flushed by two passing cars. VIDEO. Three-toed Woodpecker inhabits mountain conifer and mixed forests with large amounts of dead or dying trees. It is an absolute conifer specialist and for feeding favours standing trees where wood-boring insects and its larvae are found.
Mountain Dinaric forest of beech and silver fir (Abieti-Fagetum) - habitat of the Three-toed Woodpecker. In the Notranjska region the greenery is several weeks late in comparison to other, low-lying forests.
Fresh green leaves of beech Fagus sylvatica in the area where we found the Three-toed Woodpecker. The forest in this area has been affected by an ice storm several years ago and the consequences are still visible on the trees. Bark beetles have consequently attacked the weaker trees and have caused major dyings among conifers. Three-toed and other woodpeckers benefit from these outbreaks as they find more food (beetle's larvae) in affected stands and thus are more easily found in areas where the forest looks "poor" and ill.
Omphalodes verna is a very common woodland flower in Dinaric forests and so important in this habitat that has also given the name to the forest association Omphalodo-Fagetum. To the left of it are the shiny leaves of Geranium nodosum.
A young silver fir Abies alba slowly making its way towards the light.
Hacquetia epipactis is a characteristic flower of early spring in Slovenian forests and woods.
A male Black Woodpecker Dryocopus martius feeding on a stump, not far from its White-backed cousin. This species is widespread in a variety of forest habitats and plays a crucial role in giving other animals a home - many species readily occupy Black Woodpecker's old tree-holes.
Out of the forest - the village of Laze pri Gorenjem Jezeru by the lake Cerknica.

Friday 14 April 2017

An exciting return

The Karst is bursting with lush green leaves as the woodlands are coming back to life after long months of winter sleep. In the first photo a detail from a sessile oak Quercus petraea, a common tree species forming broadleaved woods all over Slovenia. The other two pics show a lime Tilia cordata/platyphyllos in all its spring glory.
Narcissus poeticus ssp. radiiflorus in full bloom on Karst's meadows. An increasingly scarce plant due to the loss of open meadows and pastures maintained by grazing animals. However in some areas it is still possible to see such white "carpets" like the above.
Fritillaria orientalis is a scarce and endangered species of dry limestone grassland, in bloom on the Karst at this time of year. Its even rarer wet-loving counterpart F. meleagris is found in central and eastern Slovenia.
Globularia punctata - the colour of the sky.
Pulsatilla montana is a characteristic spring flower which inhabits dry grasslands on limestone; the similar Pulsatilla vulgaris (Pasqueflower) in Slovenia is much rarer and restricted to just a few sites. The above is commonly found, but has a quite early blooming period; most of them are now already going into seed.
Paeonia officinalis at the beginning of its blooming season. This impressive plant has the biggest flower of any Slovenian species and is found in open, sunny woodlands, forest glades and wooded pastures. The real spectacle has yet to come...
Orchis morio is the commonest orchid species on the Karst, favouring unfertilised, mowed or grazed grassland. It can be seen in different colour variations, from whitish and pink to deep blue and purple.
A cherry tree Prunus avium in a vineyard on the Karst...
...where Wrynecks Jynx torquilla like to sing and nest.
Karstic rural landscape; home for Hoopoe Upupa epops, Wryneck Jynx torquilla, Corn Emberiza calandra & Cirl Bunting E. cirlus and Woodlark Lullula arborea.
The different shades of green that make wooded landscapes in spring so beautiful.
Moehringia muscosa - tough little plant, frequently growing out from the bare limestone.
Our first Short-toed Eagle Circaetus gallicus of the year, gliding above one of its favoured grassland areas, where it hunts small reptiles and snakes.
Rock Bunting Emberiza cia - a common bird of stony grassland, cliffs and rocky slopes.
Goshawk Accipiter gentilis soaring over a pine plantation. On the Karst, the species tends to use old pines for nesting and is thus associated with plantations of black pine Pinus nigra, planted by the Austrians in the 19th century.
After watching this Lesser Spotted Woodpecker Dendrocopos minor for a while, we discovered its nest in a rotten tree, some 3 meters above the ground.
A jumping Middle Spotted Woodpecker Dendrocopos medius greeting us, after two months without seeing each other.

After coming back from Romania, everything looks gorgeous here at home as spring is really in full swing. Warm sunny days, clear blue skies, lush green woodlands, birds singing everywhere and carpets of wildflowers! This is without any doubt the most exciting time of the year.
In the past days we only managed to take a few strolls around home, but it was enough to see all the above. Apart from that and the first Cuckoos Cuculus canorus, Nightingales Luscinia megarhynchos, Swifts Apus apus ect. we also saw a Red Kite Milvus milvus yesterday over Lipica (local rarity) and a Griffon Vulture Gyps fulvus on the 11th over Sežana.