The following guys (about an inch long) were seen in the Willamette Valley of Oregon in summer. When one would fly by a resting one, they'd get into a high-speed little "dogfight". What genus might they be (or species, if you know). Are they in the "skipper" group of butterflies?
$\begingroup$ That last picture reminds me of an Underwing Moth. But the clubbed antenna don't match. $\endgroup$– user137Aug 1, 2015 at 3:28
$\begingroup$ Yes, it's a skipper. But I don't know the species. $\endgroup$– CorvusAug 1, 2015 at 18:21
Yes, it is a skipper (family Hesperiidae) and very similar to European species in Ochlodes, and my guess is that it belongs to one of the North American species in this genus. For instance, it is very similar to Ochlodes sylvanoides (also called Woodland Skipper), which is common in the western parts of the US. However, I'm not familiar with North American butterflies, and there might be closely related similar species that I'm ignoring.
Images of Ochlodes sylvanoides from http://butterfliesofamerica.com/t/Ochlodes_sylvanoides_a.htm:
More pictures can also be seen at Bugguide.net
$\begingroup$ This led me to open my copy of Robert Michael Pyle's The Butterflies of Cascadia (Seattle Audubon Society, 2002); the species of the question IS Ochlodes sylvanoides, which Pyle illustrates on Plate 4 (page 81), and discusses in full (with further pictures) on pages 99-101; the range map provided on page 99 is a solid mass of blue (which means the species is found throughout the region Pyle covers). $\endgroup$ May 20, 2017 at 3:36
$\begingroup$ A late addition to my comment above: Pyle also illustrates Ochlodes sylvanoides on Plate 3 (page 77), and covers two additional species of the genus; the range maps given for both of the latter have no blue in Oregon's Willamette Valley. $\endgroup$ May 20, 2017 at 3:47