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.