Picks up some grouse's nests on the way back (6)
I believe the answer is:
senses
'picks up' is the definition.
('sense' can be a synonym of 'pick up')
'some grouse's nests on the way back' is the wordplay.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'on the way back' says the letters should be written in reverse.
'sesnes' is hidden in the letters of 'grouses nests'.
'sesnes' written backwards gives 'SENSES'.
(Other definitions for senses that I've seen before include "'Hearing, touch etc. (6)'" , "Sight, touch etc." , "Faculties for apprehending the external world" , "Feels intuitively" , "Touch and taste, e.g." .)