Conniving to make old Peruvian owl calls (2,7)
I believe the answer is:
in cahoots
'conniving' is the definition.
(I've seen this before)
'old peruvian owl calls' is the wordplay.
'old peruvian' becomes 'inca' (the Inca were a historical people of Peru).
'owl calls' becomes 'hoots' (I've seen this in another clue).
'inca'+'hoots'='IN CAHOOTS'
'to make' is the link.
(Other definitions for in cahoots that I've seen before include "Thick" , "Conspiring together" , "Working with" , "what conspirators are" , "Conniving" .)