Thursday 25 June 2020

Wildlife around summer solstice

For many birds the end of June marks the end of the breeding season. It's always sad to hear the dawn chorus weaken in the days around and after the summer solstice. Most of our intense spring fieldwork with bird censuses is coming to a close, although we'll be still carrying out our ordinary surveys and work at Škocjanski zatok NR. This week we were in the Vipava valley, checking the breeding progress of Lesser Grey Shrike Lanius minor, one of Slovenia's rarest breeding birds. The pair we recorded in May is still nesting in the same poplar, although it looks like this will be the only pair in the Vipava valley this year - and one of the very few in Slovenia overall. The birds readily use the wooden poles that have been put out for them by DOPPS-BirdLife Slovenia, as documented in the photo below.
Lesser Grey Shrike Lanius minor, Vipava valley.

In spite of the summer temperatures we also managed to observe several other interesting birds. Another national rarity inhabiting the Vipava valley is the Short-toed Lark Calandrella brachydactyla which we heard singing and observed briefly in a vineyard not far from the shrikes. Several other pairs of this rare Mediterranean species have been found in the sandy and thermophilous farmlands of the Vipava valley this year, as well as at least at one site in Istria in the extreme SW of the country. Other birds to keep us company during the census included Black Kite Milvus migrans, Crested Lark Galerida cristata, Quail Coturnix coturnix, Golden Oriole Oriolus oriolus, Red-backed Shrike Lanius collurio, Pygmy Cormorant Microcarbo pygmaeus, Cuckoo Cuculus canorus (a juvenile), while a Dipper Cinclus cinclus was on the river Vipava.
Juvenile Cuckoo Cuculus canorus, Vipava valley.
River Vipava.
European Green Lizard Lacerta viridis, Vipava valley.

After the census we visited an interesting site near the town of Vipava, with wet & dry meadows occuring side by side and hosting an interesting array of plants. In the boggier parts we enjoyed good numbers of Marsh Helleborines Epipactis palustris, while on the drier meadows we were surprised by Long-lipped Serapias Serapias vomeracea (a rare Mediterranean plant in SW Slovenia) and Yellow Flax Linum flavum.
Marsh Helleborines Epipactis palustris, Vipava valley.
Long-lipped Serapias Serapias vomeracea, Vipava valley.
Liburnian Pink Dianthus balbisii ssp. liburnicus, Vipava valley.
Yellow Flax Linum flavum, Vipava valley.
Mixture of dry & wet meadows in the Vipava valley.
Golden Beard Grass Chrysopogon gryllus, Vipava valley.

Earlier in the week we payed and evening visit to lake Cerknica and its beautiful extensive wet meadows. Among the countless singing Corncrakes Crex crex, Quails Coturnix coturnix and Sedge Warblers Acrocephalus schoenobaenus we waited for nightfall to listen for the odd croaking of a very rare breeding bird: BAILLON'S CRAKE Zapornia (Porzana) pusilla. We were lucky with two singing birds at close quarters, although the sedges were too thick to be able to see them; we only glimpsed one in flight. A small population of this secretive waterbird was discovered on the lake a few years ago and since then, ornithologists from BirdLife Slovenia are able to confirm the presence of the species on a yearly basis. This year no less than 15 singing birds were counted. For a few more photos & videos see this blog by our fellow birders - they managed to record the calls of Baillon's (2nd video) & Corncrake and even took some pics!
The evening visit to the lake was nicely spiced with other scarce or localised breeding birds such as Savi's Warbler Locustella luscinioides, Reed Bunting Emberiza schoeniclus, Snipe Gallinago gallinago, Water Rail Rallus aquaticus and Garden Warbler Sylvia borin. The wet meadows were also dotted by Bog Orchids Anacamptis palustris, as well as many other interesting acquatic or semi-acquatic plants.
Wet meadows of lake Cerknica.
Bog Orchid Anacamptis palustris, lake Cerknica.
Yellow Flag Iris pseudacorus, lake Cerknica.
Sodden sedge meadows - habitat of Baillon's Crake Zapornia pusilla.
Common Toad Bufo bufo, lake Cerknica.

Mid and late June is climax time for butterfly & moth diversity in the western part of Slovenia, so Lepidopteras were also our special focus recently. One of the most interesting species we went looking for was the False Ringlet Coenonympha oedippus. This localised and highly endangered species lives in two ecologically different habitats in Slovenia: wet boggy meadows at Ljubljansko barje and dry karstic grasslands in the Karst, Goriška brda and Istria. Sadly the populations on wet meadows have become nearly extinct in recent years due to the intensification of farming. However a reintroduction project has been recently launched and some weeks ago the first captive butterflies have been released to meadows managed by BirdLife Slovenia. The western part of the Karst around Komen is one of the local stronghold of the species and that's where we managed to observe the butterfly. False Ringlet likes overgrown karstic meadows that have been taken over by bushes and small trees such as Smoke Bush Cotinus coggygria or Manna Ash Fraxinus ornus. However it also requires some open areas and thus the later successional stages including dense shrubland and young woodland are not suitable for it. One of the problems in the Karst is the rapid overgrowing of meadows with the Asian invasive Tree of Heaven Ailanthus altissima.
False Ringlet Coenonympha oedippus, Karst around Komen.
False Ringlet habitat, although partly overgrown by Ailanthus altissima.
Sooty Copper Lycaena tityrus, Karst around Komen.
Spotted Fritillary Melitaea didyma, Karst around Komen.
Small Copper Lycaena phlaeas on White Lace Flower Orlaya grandiflora, Karst around Komen.
Owlfly Libelloides macaronius, Karst around Komen.
Nine-spotted Moth Amata phegea, Karst around Komen.
Feathered Footman Spiris striata, Karst around Komen.
Beech Longhorn Beetle Morimus funereus, Karst around Komen.
On the lookout for Leps.

During last week we've been also playing with a moth trap that we borrowed from our friend Paul. We positioned the trap in different places around the garden: in front of the house, in the orchard garden and behind the house at the woodland's edge. The latter is perhaps the best location and we'll keep trying there in the next nights. So far we caught several amazing species (much to Paul's great envy) that are shown in the pics below. As beginners we tend to overlook the smaller moths and focus on the bigger ones - the highlights were certainly Oak Hawk-moth Marumba quercus and Goat Moth Cossus cossus. A full moth-trapping report in one of the future posts.
Oak Hawk-moth Marumba quercus, Karst around Sežana.
Plum Lappet Odonestis pruni, Karst around Sežana.
Lobster Moth Stauropus fagi, Karst around Sežana.
Goat Moth Cossus cossus, Karst around Sežana.
Argentine Moth Spatalia argentina, Karst around Sežana.
Hungarian Buff-tip Phalera bucephaloides, Karst around Sežana.

Meanwhile the routine work at Škocjanski zatok Nature Reserve continues as usual. At the moment we are paying special attention to the breeding Little Bitterns Ixobrychus minutus, trying to chart their territories. Something about 8-10 pairs breed at the reserve, however they are not easy to see as they tend to hide in the reeds and make only short flights between their favoured areas. The easiest place to see one is actually Domen's office window! Two weeks ago we confirmed the nesting of a pair of Wrynecks Jynx torquilla in the reserve (the parents were busy feeding their chicks - already fledged now). The waders in the brackish lagoon are doing well: we observed fledged juveniles of Kentish Plover Charadrius alexandrinus (2 pairs), and Avocet Recurvirostra avosetta (2-3 pairs), as well as many Black-winged Stilts Himantopus himantopus. Common Sterna hirundo and Little Terns Sternula albifrons are also busy feeding their chicks now. 
Last week we also observed 3 of the around 40 European Pond Terrapins Emys orbicularis censused at the reserve. This rare and difficult-to-see turtle is the only native freshwater turtle in Slovenia. It is highly threatened by the increased presence of the alien Pond Slider Trachemys scripta, an introduced species from America.
Little Bittern Ixobrychus minutus (male), Škocjanski zatok NR.
Avocet Recurvirostra avosetta (fledgling in the second pic), Škocjanski zatok NR.
Kentish Plover Charadrius alexandrinus, Škocjanski zatok NR.
Little Ringed Plover Charadrius dubius & Little Tern Sternula albifrons, Škocjanski zatok NR.
Hoopoe Upupa epops, Škocjanski zatok NR.
European Pond Terrapin Emys orbicularis, Škocjanski zatok NR.
European Tree Frog Hyla arborea, Škocjanski zatok NR.