Distribution: Very local in the Alps of France, Switzerland Austria
and Italy. Probably underreported in this region.
Identification: Its small size makes it relatively easy to distinguish
in the field from the other Pyrgus species with which it flies. The
upperside fw spots are generally very small with pale scaling in basal area and
a small basal spot (or pair or spots). The upperside hindwing has a rectangular
smudge in the discal area and a row of submarginal spots, equally indistinct but
definitely present.
In a study in Switzerland there was only a very slight overlap in wing length
at 14mm with the Large Grizzled Skipper, P. alveus, its most similar
close relative. It also emerged 14 days earlier than its larger relative. I've
read that warrenensis hugs the ground in flight where as alveus
may fly as high as 1m above the ground.
Flight time: Probably end June to mid July from my experiences in
Switzerland. Reportedly July/August.
Habitat: Sheltered grassy alpine meadows with flowers.
Behaviour: Appears to fly principally along low embankments
beside streams. Also likes to perch on small stones where it basks in the
sunshine.
Additional notes: It is quite conceivable that this species is more
common than reported. This may be due to its early flight time at these
altitudes
