This year I visited in total 3 times the Asolo hills (“Colli Asolani”), in Treviso province, during the second half of August, when since 1994 an increasing number of birdwatchers meet to count the raptors on fall migration. The usual number of counted birds, in about 3 weeks each year, was between 6,000 and 12,000, but in 2017 the migration was different, with a number of migrants much lower than usual (almost 4,000 birds), probably because of a different flyway taken, apparently far from the hills.
The reason of this change is hard to tell, but might involve a differend distribution of thermals because of above average hot temperatures of the second half of summer.
Despite this, the time there is always delightful, with a very friendly ambience, nice people, lovely breezy climate and amazing view that embrace the Veneto plain on one side, with the far belltowers of Venice and the vulcanic shapes of Colli Euganei, and the Prealpi range on the other, with the massive Monte Grappa (1,775 m) and the Cesen (1,570 m). There you can chill out and sit in the shade of a little Catholic temple of San Giorgio, talking with old and new friends, and observing the birds of prey coming from north-east.
During the 3 days I spent on the top of the Colle San Giorgio, in the Maser municipality, I watched hundreds of Honey Buzzards (Pernis apivorus), tens of Common Buzzards (Buteo buteo) and a single Black Kite (Milvus migrans), but quite e few local raptors, breeding along the Colli Asolani, appeared: Short-toed Eagle (Circaetus gallicus), Eurasian Sparrowhawk (Accipiter nisus), Common Kestrel (Falco tinnunculus), Hobby (Falco subbuteo) and Peregrine Falcon (Falco peregrinus).
The flora of the Colli Asolani is pretty peculiar, with a mix of mediterranean and alpine species: about trees, the Olive (Olea europaea) here meets the Scots Pine (Pinus sylvestris). But also the small flora is expression of this mix, with European Michaelmas-daisy (Aster amellus), Autumn Crocus (Colchicum autumnale), Amethyst Eryngo (Eryngium amethystinum) and many more.
This particular habitat hosts an rich least fauna with lizards like Common Wall (Podarcis muralis) and Western Green (Lacerta bilineata), but also colourful insects, including the wasp Scolia hirta, the burnet Zygaena carniolica and a lot of European Mantis (Mantis religiosa).
But what I found more interesting was the amazing variety of butterflies encontered:
- Common Swallowtail (Papilio machaon)
- Scarce Swallowtail (Iphiclides podalirius)
- Common Clouded Yellow (Colias crocea)
- Wood White (Leptidea sinapis)
- Eastern Bath White (Pontia edusa)
- Brown Argus (Aricia agestis)
- Short-tailed Blue (Cupido argiades)
- Adonis Blue (Lysandra bellargus)
- Common Blue (Polyommatus icarus)
- High Brown Fritillary (Argynnis adippe)
- Silver-washed Fritillary (Argynnis paphia)
- Queen of Spain Fritillary (Issoria lathonia)
- Heath Fritillary (Melitaea athalia)
- Spotted Fritillary (Melitaea didyma)
- Knapweed Fritillary (Melitaea phoebe)
- Great Banded Grayling (Brintesia circe)
- Pearly Heath (Coenonympha arcania)
- Scotch Argus (Erebia aethiops)
- Woodland Grayling (Hipparchia fagi)
- Wall Brown (Lasiommata megera)
- Meadow Brown (Maniola jurtina)
- Dryad (Minois dryas)
- Gatekeeper (Pyronia tithonus)
- Silver-spotted Skipper (Hesperia comma)
- Large Skipper (Ochlodes sylvanus)