Water is vital.

 The California Sister finds water when to the casual observer everything seems dry.  Here's a group stopping for drinks on little wet cracks in the Feather River College driveway.

 They spend most of their drinking time with wings folded over their backs.  It took me quite a few tries to catch one with its wings extended.

This one was deep in the branches of a willow by the Middle Fork of the Feather River.  Might have been just enjoying the shade, or might have been laying eggs on a branch, or both.