Jittery type with an eye for the birds? (8)
I believe the answer is:
twitcher
I believe this is a double definition.
'jittery type' is the first definition.
(someone who twitches)
'with an eye for the birds?' is the second definition.
(twitcher can mean a birdwatcher)
(Other definitions for twitcher that I've seen before include "Bird watcher" , "Spasmodic" , "One not still" , "Rare bird spotter" , "Bird-watcher (colloq)" .)