Friday, 19 July 2019

Summer birding & beetle hunting

Summer is slowly gaining its heating power again, after a relatively cold and windy period. Due to rain showers and cold temperatures (sometimes barely above 20 degrees C) it hasn't been that good for butterflies. Fortunately new generations of Lepidopteras are emerging just now and numbers as well as variety are again slowly on the rise. Recently we've been slightly luckier with birds. In the Vipava valley we observed a male Spanish Sparrow Passer hispaniolensis holding territory, among a group of Tree P. montanus and Italian Sparrows P. italiae. We didn't find any sure signs of breeding, but if the bird is indeed nesting in the area, this would represent only the second ever nesting for this Mediterranean species in Slovenia. The only other nesting was reported from Slovenian Istria, in the extreme south-west, where the species is still occasionally recorded on passage. The nearest breeding colonies of Spanish Sparrow to Slovenia are in nearby Croatia, some 12 km from the south-western border.
Spanish Sparrow Passer hispaniolensis

In the Vipava valley we also observed again a Black Stork Ciconia nigra, not far from the place we saw it in spring and where its presumed nesting territory is. Unfortunately this year we hadn't time to investigate more, but next season we'd like to track down more precisely where this pair nests and confirm the breeding. A juvenile fledged Hoopoe Upupa epops was nearby and showing well, whilst feeding on a gravel road a few meters from us. A few butterflies and plants were interesting to see, but not in the usual numbers and variety one would expect in mid summer.
Black Stork Ciconia nigra
Hoopoe Upupa epops
Weaver's Fritillary Boloria (Clossiana) dia
Liburnian Pink Dianthus balbisii subsp. liburnicus

In the Karst we've been mainly entertained by our local pair of Short-toed Eagles Circaetus gallicus, while on the invertebrate front we were after the typical large beetles of oak woodlands. Apart from the many Stag Beetles Lucanus cervus we see almost on a daily basis in our garden, we've been also pleased to find again, on the same tree like every year, the rarer Great Capricorn Beetle Cerambyx cerdo. This beetle needs decaying oak wood and is found in areas where older oaks are present. It is widespread across Slovenia, but rather rare overall. The most impressive thing about this species is the size: the one we saw measured about 7-8 cm (excluding the extremely long antennae). Finally we also saw a Beech Longhorn Beetle Morimus funereus, which although common, is always a pleasant find. All the above mentioned beetles (as well as the Rosalia Longicorn) are red-listed and Natura 2000 species.
One evening, while checking the breeding success of a pair of Eagle Owls Bubo bubo (no confirmed breeding this year) we heard a group of Golden Jackals Canis aureus howling at the church bells of the nearby village - a quite common behaviour in the Karst.
Great Capricorn Beetle Cerambyx cerdo
Stag Beetle Lucanus cervus (male above, female below)
Beech Longhorn Beetle Morimus funereus

In the last posts we haven't mentioned Škocjanski zatok Nature Reserve much, although we've been monitoring birds there on a regular basis. Among the most exciting recent news is the nesting of a new species for the reserve: the Avocet Recurvirostra avosetta. In June, during breeding birds monitorings, a nest with 4 eggs was found in the brackish lagoon, while in the past two weeks we've been observing two adults escorting 3 fledged juveniles. The lagoon is very lively at this stage as the breeding colonies of terns and other waders are full of hungry juveniles. Among species nesting in good numbers are Common Tern Sterna hirundo, Little Tern Sternula albifrons, Black-winged Stilt Himantopus himantopus, Redshank Tringa totanus and Little Ringed Plover Charadrius dubius.
In this season we are also following the movements of Little Bitterns Ixobrychus minutus breeding at the reserve and we are regularly observing 3-4 different pairs. The summer-autumn wader passage has already began and birds like Wood Sandpiper Tringa glareola, Common Sandpiper Actitis hypoleucos, Green Sandpiper Tringa ochropus, Curlew Numenius arquata and Snipe Gallinago gallinago are already back after their late-spring absence. Other interesting birds observed recently (in the past week) at the reserve include: Short-toed Eagle Circaetus gallicus (with a snake!), Spoonbill Platalea leucorodia (up to 8), Black Tern Chlidonias niger (1 juv), Cattle Egret Bubulcus ibis (1), Zitting Cisticola Cisticola juncidis (1-2 on a daily basis), Alpine Swift Apus melba, Purple Heron Ardea purpurea (1 nesting pair) and Pygmy Cormorant Phalacrocorax pygmeus (up to 8). More updated sightings on the reserve's Facebook page.
Avocet Recurvirostra avosetta
Common Tern Sterna hirundo
Little Bittern Ixobrychus minutus
Freshwater marsh at Škocjanski zatok NR.
Water Rail Rallus aquaticus (juvenile).
Short-toed Eagle Circaetus gallicus
Spoonbill Platalea leucorodia

Friday, 12 July 2019

Alpine Longhorn Beetle - a dream comes true

Some animals are so charismatic, yet so elusive or rare, that the wish to see them escalates on every failed encounter. Sometimes they haunt you for years and you never seem to be lucky, no matter how much you try. For us this was the case with the beautiful Alpine Longhorn Beetle or Rosalia Longicorn Rosalia alpina, which until a few days ago, proved to be a mythical beast. This impressive longhorn beetle of the Cerambycidae family is rare on a European level and listed as vulnerable (VU) by the IUCN. Needles to say it is also a Natura 2000 species for which some special protection sites have been designated in Slovenia. Its life cycle is linked to the beech Fagus sylvatica and thus it is mainly found in mountain beech forests, especially those in warmer, sunnier areas of the Alps, but also other mountain and hilly areas of central and southern Europe. In Slovenia it is found in different regions, but nowhere in large densities. It is somewhat commoner in the Julian Alps, some parts of the Dinaric mountains and in some wooded hills of the Štajerska region. The essential element in its habitat is dead beech wood. Males and females are especially attracted to freshly wounded trees, but also cut timber and log piles. Apparently the smell of wounded beech wood proves irresistible to them. The easiest way to look for an Alpine Longhorn Beetle (but also other species of Cerambycidae, like the Beech Longhorn Beetle Morimus funereus for example) is to carefully check beech log piles in deciduous forests in July and August. 
A few days ago we visited the Trenta valley at the heart of the Triglav National Park in the Julian Alps, with the intention to look for this rare longicorn. This time we were finally successfull as we found a nice log pile at the side of a road, where up to 5 stunning Alpine Longhorn Beetles were sunbathing!
Alpine Longhorn Beetle Rosalia alpina

The adult Alpine Longhorn Beetles emerge in summer and can be seen basking in the sun, mating or depositing the eggs on the logs. Sadly these log piles act as traps as they are taken away from the forest, with whole broods of longhorn beetles, which are subsequently destroyed during the industrial processing of the timber. A simple measure to avoid this would be to quickly remove the logged trees from the forest, before the beetles could lay their eggs in them. Another measure to help longhorn beetles is to leave some log piles in the forest without removing them. This is exactly what the Triglav National Park has done recently by placing a permanent log pile and an info board about the Rosalia Longicorn along a tourist trail in the Trenta valley. Now in the summer months visitors can read about this rare beetle and with a bit of luck, spot one basking on the logs. After finding our own longicorns at another site, we also payed a visit to this demonstration log pile called Rosalium, where amazingly 3 more Alpine Longhorn Beetles were there for all the visitors to enjoy. Very didactic!
The "Rosalium"
A tame Alpine Longhorn Beetle Rosalia alpina decided to land on my hand. Yes, the can fly!


The longhorn beetles could have been enough to make our day, but the Trenta valley provided some other interesting wildlife. Among birds we saw several Crag Martins Ptyonoprogne rupestris and heard a Western Bonelli's Warbler Phylloscopus bonelli, while butterflies of note included Styrian Ringlet Erebia stirius, Mountain Green-veined White Pieris bryoniae, Chalkhill Blue Lysandra coridon and Arran Brown Erebia ligea.
We were also very glad that Mitja Denac gave us a tip on where to see Creeping Lady's-tresses Goodyera repens - a tiny orchid sprouting in summer under conifer trees. It was a lifer for us! Finally we also enjoyed in seeing good numbers of the rare Tufted Horned Rampion or Devil's Claws Physoplexis comosa, although they weren't in full bloom anymore.
Chalkhill Blue Lysandra coridon
Styrian Ringlet Erebia stirius
Creeping Lady's-tresses Goodyera repens (thanks to Mitja Denac!)
Tufted Horned Rampion Physoplexis comosa
Yellow Bird's-nest Monotropa hypopitys
Dark-red Helleborine Epipactis atrorubens
Hairy Alpenrose Rhododendron hirsutum
Mountain views from the Trenta valley.

Sunday, 7 July 2019

Rare butterflies in Trnovski gozd

Some days ago we visited one of Slovenia's butterfly hotspots, the southern edge of Trnovski gozd (the Trnovo forest). This is an area of dry mountain meadows at an altitude between 1000-1200 meters above the sea, bordered by the mixed Dinaric forests of the Trnovo plateau. The area is so rich with butterflies (but also floristically diverse) because it lays right along the Dinaric ridge, which represents a meeting point of different biogeographical regions. Here plants and animals typical of the Mediterranean mix with those from the continent, the Alps and the Balkans.
During our visit we observed 35 species of butterflies, many of which were interesting, scarce or locally rare species. We were mostly excited by the find of several Apollos Parnassius apollo, one of Slovenia's rarest and most endangered butterflies (see last year's post), but also other local specialities like Styrian Ringlet Erebia stirius, Great Sooty Satyr Satyrus ferula and Clouded Apollo Parnassius mnemosyne. This time we were so excited that we even wrote a complete butterfly check-list of the trip - you can find it at the end of the post.
Apart from butterflies we enjoyed in the carpets of flowering mountain plants, including many rare ones like White Sainfoin Onobrychis alba, Grass-leaved Scabious Scabiosa graminifiolia, the endemic Hladnikia Hladnikia pastinacifolia (only found in Trnovski gozd and nowhere else), Carniolan Lily Lilium carniolicum, Spiked Bellflower Campanula spicata, Carniolan Vetch Astragalus carniolicus and many many others. Among birds the most interesting sights were all from the road: 3 Short-toed Eagles Circaetus gallicus (2 near Sežana and 1 near Vipava) and a fly-by Hoopoe Upupa epops in the Vipava valley. In the dry mountain meadows Rock Buntings Emberiza cia were most prominent.

Mountain meadows above the Vipava valley.
Apollo Parnassius apollo. We observed at least 4 different.
Some say the "eye" markings on the Apollo's wings were the main inspiration for the colour signs that are used in Slovenia for marking mountain paths.
Great Sooty Satyr Satyrus ferula.   
A localised species of dry rocky places along karstic ridges in western Slovenia.
Styrian Ringlet Erebia stirius.  
 An alpine species with isolated populations in the Dinaric mountains 
(Trnovski gozd, Nanos and Kočevsko).
Arran Brown Erebia ligea
Queen of Spain Fritillary Issoria lathonia
Great Banded Grayling Brintesia circe
Lesser Spotted Fritillary Melitaea trivia
Assman's/Nickerl's Fritillary Melitaea britomartis/aurelia
Marbled White Melanargia galathea
High Brown Fritillary Argynnis adippe
Pearly Heath Coenonympha arcania
Black-veined White Aporia crataegi
Grayling Hipparchia semele
Silver-washed Fritillary Argynnis paphia (dark form valesina)
Brimstone Gonepteryx rhamni
Spiked Bellflower Campanula spicata
Rock Bunting Emberiza cia


Complete butterfly check-list of the day (not in systematic order) - tot. 35 species:

Blue-spot Hairstreak Satyrium spini
Marbled White Melanargia galathea
Pearly Heath Coenonympha arcania
Small White Pieris rapae
Silver-washed Fritillary Argynnis paphia
Styrian Ringlet Erebia stirius
Heath Fritillary Melitaea athalia
Chestnut Heath Coenonympha glycerion
Scarce Swallowtail Iphiclides podalirius
Common Swallowtail Papilio machaon
Queen of Spain Fritillary Issoria lathonia
Brimstone Gonepteryx rhamni
Lesser Spotted Fritillary Melitaea trivia
High Brown Fritillary Argynnis adippe
Large Wall Brown Lasiommata maera
Painted Lady Vanessa cardui
Spotted Fritillary Melitaea didyma
Large Skipper Ochlodes sylvanus (venatus)
Peacock Aglais io
Great Banded Grayling Brintesia circe
Clouded Apollo Parnassius mnemosyne
Grayling Hipparchia semele
Mazarine Blue Cyaniris semiargus
Common Blue Polyommatus icarus
Arran Brown Erebia ligea
Meadow Brown Maniola jurtina
Assman’s/Nickerl’s Fritillary Melitaea britomartis/aurelia
Black-veined White Aporia crataegi
Small Blue Cupido minimus
Large White Pieris brassicae
Apollo Parnassius apollo
Large Chequered Skipper Heteropterus morpheus
Duke of Burgundy Hamearis lucina
Great Sooty Satyr Satyrus ferula
Scotch Argus Erebia aethiops

Read more about Slovenian butterflies and their diversity on our website: Butterflies of Slovenia.