Wednesday 7 April 2021

Chasing White-backs & Middle Spots

Although Slovenia is now in the middle of a very cold and snowy front (more about that at the end of the post), the past weeks have been surprisingly sunny and warm, allowing extensive woodpecker surveying sessions. Domen has been busy searching for breeding White-backed Woodpeckers Dendrocopos leucostos ssp. lilfordi in the wildest and most forgotten corners of the Snežnik plateau. Some of these areas support large quantities of dead beech wood which is full of signs (feeding, nesting...) of this rare woodpecker, however locating and following the birds is rather challenging, given the extremely "varied" terrain. White-backed's favourite habitats are located in areas of old beech forests in extremely rocky and rugged terrains, full of dolinas (sinkholes), steep ridges and depressions, where forestry activity has been rendered difficult or impossible. At this time of year there's still a considerable amount of snow which in some places complicates the matter even more. If at the beginning of March Brown Bears Ursus arctos were probably not out of the dens yet, now the situation is clearly different. Their footprints in the snow are everywhere (including those of mum bears with newly born cubs) and they even outnumber those of the omnipresent Red Deer Cervus elaphus. Here and there you can also find the occasional footprint of Wolf Canis lupus.
Brown Bear's tracks in the forests of Snežnik.
Mama Bear and this year's cub.
Adult Brown Bear Ursus arctos.
Footprint of Wolf Canis lupus.
White-backed Woodpecker's habitat.
Fresh feeding signs of White-backed Woodpecker.
White-backs frequently feed on the ground on smaller pieces of rotten logs.
Freshly excavated nest-hole of White-backed Woodpecker.
There are certainly more signs that there are White-backed Woodpeckers! Despite a considerable surveying effort we were able to locate only a few individuals, although we didn't search an extensive area, but only part of a large forest reserve. With the kind help of friends we so far tracked down 3 different territories of White-backs, although we didn't locate any active nest-holes yet. The breeding activity seemed a bit slow and only occasionally the woodpeckers were drumming. It was however interesting to watch these rare birds feeding on the ground on small pieces of rotting wood. In the selection below is a female that showed particularly well and allowed us to record a decent video. Note the large white grubs she digs out on two occasions in the video - these represent the species' most important food source.

Female White-backed Woodpecker Dendrocopos leucotos ssp. lilfordi feeding on a rotten beech log.


Other birds in the forest are showing more prominent signs of breeding like Nuthatches Sitta europaea that we observed nest-building on several occasions. One of them was adapting an old White-backed Woodpecker's nest-hole in a standing dead beech. Otherwise Tawny Strix aluco and Ural Owls Strix uralensis are very vocal and several individuals of each are usually heard during our fieldwork, even in the middle of the day. Owls this year probably don't need to put much effort into hunting as the forest floor is still teeming with large numbers of Bank Voles Myodes glareolus. During one of our last trips we were also very lucky to find a freshly shed and amazingly big Red Deer's antler - something you certainly don't come across every day, especially if you don't go specifically looking for it.

Freshly shed antler of Red Deer Cervus elaphus.
How to make a very happy boy!
Christmas Rose Helleborus niger
Brimstone Gonepteryx rhamni on White Crocus Crocus vernus ssp. albiflorus.
But winter has won... for now.
Comma Polygonia c-album
The dry stony grasslands on the south-western edge of Snežnik's plateau.
Back in March we also went to check some rather unlikely White-backed Woodpecker's territories in the commercial forests of Javorniki, where, despite extensive logging in the area, a pair was found drumming intensively at sunrise (a clear sign of breeding). Sadly such scenes of intensive logging as depicted below are an increasingly common feature across Slovenian forests, regardless of the area or region. 
Heavy logging in a commercial forest where White-backed Woodpecker breeds.

White-backed Woodpecker Dendrocopos leucotos ssp. lilfordi, male & female territorial drumming.


Meanwhile Sara has been extensively surveying Middle Spotted Woodpeckers Leiopicus medius and parameters of their nesting habitat in the Karst's oak forests. So far she recorded up to 29 territorial Middle Spots, mostly in the known areas of mature oak stands where we've been studying the species over the past years. The species seems to be doing well in western Slovenia, continuing its range expansion westwards and being also discovered at new sites, which were previously "empty". Censuses in the last week were particularly pleasing as, apart from woodpeckers, the supporting cast in the woodland and nearby meadows also included the amazing spring chorus of singing Hoopoes Upupa epops, Cuckoos Cuculus canorus and Wrynecks Jynx torquilla that have all just returned from Africa. During a forest birds transect census we also met with our local Ural Owl Strix uralensis (calmly napping as usual), as well as with a pair of Black Woodpeckers Dryocopus martius excavating a new nest-hole.

Middle Spotted Woodpecker Leiopicus medius
Habitat of Middle Spotted Woodpecker in the Karst, with predominant species including Quercus petraea & Quercus cerris.
Hoopoe Upupa epops - male singing
Can you see it?
The unmistakable shape of a...
...sleepy Ural Owl Strix uralensis
Black Woodpecker Dryocopus martius (male), sunbathing in the second pic.

Red Squirrel Sciurus vulgaris licking the asphalt in the company of a Hawfinch Coccothraustes coccothraustes.
Common Toads Bufo bufo in amplexus, trying to cross a forest road.
Spring Heath Erica carnea
Dog's-tooth Violet Erythronium dens-canis
Hacquetia Hacquetia epipactis
Peacock Aglais io
Mountain Pasqueflower Pulsatilla montana, an attractive and rather common plant of dry karstic grasslands.
As we mentioned in the introduction, at the time of writing we are in the middle of an extremely cold front that on the 6th of April brought heavy snowfalls over much of Slovenia, including the Karst where we live. Hoping the weather will get warmer as soon as possible (think about all the insectivorous spring migrants, plants ect!), we round up the post with these unusual scenes from the woodlands around our home...
The final clash between winter and spring.