My copy of _Pocket Guide to the Birds of Britain and North-West Europe_
notes that the Nightjar's flight is kestrel-like and offers this tip:

"Look for singing bird perched on bushtop or prominent dead limb" (p. 176)

Pat
(who likes Hardy's poetry so much more than his prose)

Pat Valdata, Elkton, MD | 
"I love deadlines. I like the whooshing sound they make as they fly by."
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