Sunday 12 April 2020

Three are the magic things

Three-toed Woodpecker Picoides tridactylus ranks among the rarest European woodpeckers and although Slovenia holds some good populations of this species, it still remains a rare breeding bird in the country. It is only found in mountain conifer forests above 700 m a.s.l. and usually needs older stands with dead or decaying conifer wood to survive. Yesterday we carried out the species' census in the Dinaric forests of the Javorniki mountains, along our traditional transect we've been monitoring for the past 5 years or so. The situation with breeding density in this area usually varies from year to year according to logging activities - unfortunately the whole transect runs in commercial forest. The overall global trend of extreme forest exploitation is obviously present in Slovenia too. As we've been previously pointing out, the situation is quite worrying in several areas of natural importance (Natura 2000 sites) where rare or endangered species live. The Javorniki mountains are one good example. Yesterday we noticed new logging activity in areas where Three-toed Woodpeckers used to breed in previous years. Nevertheless we still managed to confirm 4 territorial birds on the transect and enjoy one particular male that showed extremely well while drumming.
 Male Three-toed Woodpecker Picoides tridactylus drumming

"Sustainable logging" in breeding territories of Three-toed Woodpecker
(and other Natura 2000 species).

Due to the general lockdown the white roads were unusually quiet so we had the forest all for ourselves. The only other human beings we encountered were some colleague biologists doing research in the forest. Not even hunters or loggers were around this time and once for a change, even chainsaws were silent. It was priceless!
Among other birds Grey-headed Picus canus and Black Woodpecker Dryocopus martius were commonly heard, while the usual suspects of mountain forests including Firecrest Regulus ignicapillus, Willow Tit Poecile montanus, Crested Tit Lophophanes cristatus, Bullfinch Pyrrhula pyrrhula and the increasingly commoner Woodpigeon Columba palumbus were around.
At this time of year one would expect a quite impressive spectacle of wildflowers on the forest floor, but given the prolonged drought, plants are struggling to put on a good show this year. However one plant in particular made us very happy - it is one of the most charismatic species in the Slovenian flora: Henbane Bell Scopolia carniolica. This relative of the potato (family Solanaceae) grows in wet, shady places in the beech forests of central and southern Slovenia (as well as in other central and SE European countries). Joannes Antonius Scopoli (1723-1788) was the first to describe this species from specimen collected in Idrija (central Slovenia) and consequently received the honor to have this plant named after him. Another species described by Scopoli and with its locus classicus in Slovenia is the Small White Sedge Carex alba. Although quite uninpressive, this plant builds up its own forest association with beech: Carici albae-Fagetum.
Henbane Bell Scopolia carniolica (note the bumblebee in the last pic).
Henbane Bell Scopolia carniolica forming a dense understorey with Ramsons Allium ursinum.
Small White Sedge Carex alba
Three-leaved Valerian Valeriana tripteris

On our way back home we drove along the western side of lake Cerknica which was almost completely dry. The current prolonged drought (in March and April it didn't rain so far!) is very unusual for this season, when this temporary lake should be filled with rainfall and snow-melt waters. This will probably have a bad impact on the breeding birds on the lake. While driving along the dry lake's floodplain we noticed a large flock of Great Egrets Ardea alba and Grey Herons Ardea cinerea. To our surprise 6 Black Storks Ciconia nigra were also among them - all where adults, except one in clear juvenile plumage. Although the species breeds with one pair in the lake's surroundings, it is likely that this group involved birds on migration. Meanwhile White Storks Ciconia ciconia have returned to their traditional nests on chimneys in the local villages.
Black Stork Ciconia nigra (part of a group of 6).