Monday 26 December 2016

Winter life in Karst woodlands

Sessile oaks Quercus petraea, Slovenian Karst, December 2016.
Loranthus europaeus, Slovenian Karst, December 2016. A parasite plant, growing mostly on large oaks and a relative of mistletoe Viscum sp. The fruits become yellow in winter and are a favourite food of Mistle Thrushes Turdus viscivorus. The birds eat the fruits and disperse the seeds on other trees with their droppings. Mistle Thruhes also fiercely defend "their" trees full of Loranthus from other thrushes.
Mistle Thrush Turdus viscivorus, Slovenian Karst, December 2016. A common encounter even in the most desolate forests in winter. Recently I've been seeing also smaller numbers of its relatives: Fieldfares Turdus pilaris and Redwings Turdus iliacus. In Karstic woodlands they like to feed on ivy Hedera helix berries, as well as the above-mentioned Loranthus.
Woodpecker's "anvil", Slovenian Karst, December 2016. The bark of large oaks, especially Turkey oak Quercus cerris (above) is a favourite place for woodpeckers to stuck seeds and nuts. They position the seed firmly and then hammer it with the beak to break the shell. The above is probably work of a Great Spotted Woodpecker Dendrocopos major.
Middle Spotted Woodpecker Dendrocopos medius, Slovenian Karst, December 2016 (last photo: Sara Cernich). The above is an individual observed repeatedly at one of the reliable sites I know, where, with a bit of patience, the bird makes itself visible. In my experience, these birds tend to be quite shy and are difficult to approach, although frequently heard. The first pic shows a classic behaviour of the Middle Spot: hiding behind a branch and cautiously observing.
Grey-headed Woodpecker Picus canus, Slovenian Karst, December 2016. Quite frequent in mature Karst's woodlands, but not always easy to observe. Above is a male (red front), together with a Hawfinch Coccothraustes coccothraustes in the second photo.
Great Spotted Woodpecker Dendrocopos major (male), Slovenian Karst, December 2016. Birds have already started to drum and are becoming territorial. Apart from Great Spotted I also heard the powerful rolling drums of a Black Woodpecker Dryocopus martius and heard a pair making courtship calls. In winter, hearing the sound of a drumming woodpecker already brings the joyful feelings of spring!
Corylus avellana, Slovenian Karst, December 2016. Hazel's catkins (male flowers) begin to appear in sunny oak woodlands across the Karst.
Hawfinch Coccothraustes coccothraustes, Slovenian Karst, December 2016. In Karst's woodlands is common in winter as it is in spring. Small flocks regularly visit bird tables and feeders in gardens.
Blue Tit Cyanistes caeruleus, Slovenian Karst, December 2016, (photo: Sara Cernich). Forming winter flocks with other tits, such as Great Parus marjor & Marsh Poecile palustris, but also with Nuthatch Sitta europaea and Treecreepers Certhia sp.
Andricus lucidus, Slovenian Karst, December 2016. One of the several galls made on oaks in Karst's woodlands. This one was on a sessile oak Quercus petraea. Recently I've been observing more accurately the galls encountered on oaks and trying to ID them, so I'm getting the grips with cecidology.
Andricus caputmedusae on sessile oak Quercus petraea, Slovenian Karst, December 2016. Another frequent gall on oaks; perhaps the most common here after Andricus quercustozae which is most frequently seen on downy oak Quercus pubescens.
Neuroterus quercusbaccarum, Slovenian Karst, December 2016. Another gall, especially common on leaves of Turkey oak Quercus cerris (as above) - easily seen in late autumn on dry leaves on the ground.
Dolichomitus mesocentrus, Slovenian Karst, November 2016. A parasite wasp (Hymenoptera) that probably does what Attenborough says in the second part of this video (min 3.58) - he will certainly explain it better than me.
Helleborus multifidus ssp. istriacus, Slovenian Karst, December 2016. The harbinger of spring? Not quite... proper winter has yet to arrive here. This flower is usually one of the earliest to sprout, even in mid winter.
Ural Owl Strix uralensis, Trnovski gozd, December 2016. For a change, also a pic from the forested high karst plateaus. In winter Ural Owls are commonly encountered in complete daylight, hunting rodents beside forest roads and clearings. Some days ago I saw up to 4 different birds on a strecth of about 3 km along a forest road.