Report from 6 to 8 June 2023

The first returning Green Sandpiper always marks a shift in the calendar. The very last northbound migrants were still coming through in late April, and now we are already seeing the first southbound individuals. Spoonbills are also undergoing seasonal movements: in addition to the two adults that have been with us all spring, we also saw five juveniles, one of which was sporting a colour ring that identified it as coming from France’s Camargue.
Two Ruddy Shelduck drakes put in a fleeting appearance. With this species, origin – wild or escaped – is always a very challenging issue. For what its worth, these two individuals were exceptionally wary. An Osprey also put in an appearance this week.
We saw the year’s first Japanese Beetles (Popillia japonica), an invasive alien species with a devastating impact. And speaking of non-native species, in recent days we are seeing many female Pond Sliders(Trachemys scripta), a North American aquatic turtle, laying their eggs in holes they dig in the soft soil. And to think that one of my old books claimed that this species “is unable to reproduce” in Italy.
The heat and extreme drought of the past year have taken their toll on our local butterflies, which are only partially recovering now. Most of the ones we currently see are in the family Pieridae, while the other taxonomic groups, including Nymphalidae, Liycaenidae, and Hesperidae, remain very scarce. I have carried out standardized surveys for several years now: in recent weeks, the six species of Pieridae present at La Cassinazza account for over 70% of all butterflies seen.

The Southern Small White (Pieris mannii) depicted in the photo is the least known of the six, from which it can be distinuguished by minute differences in the shape and pattern of the black wing spots.