About time birds of prey start to show enthusiasm (9)
I believe the answer is:
eagerness
'enthusiasm' is the definition.
(eagerness is a kind of enthusiasm)
'about time birds of prey start' is the wordplay.
I cannot quite see how this works, but
'about' could be 'a' (abbreviation in Chambers) and 'a' is found in the answer.
'birds' could be 'ernes' (erne is a kind of bird) and 'ernes' is present in the answer.
This may be the basis of clue (or it may be nonsense).
'to show' acts as a link.
Can you help me to learn more?
(Other definitions for eagerness that I've seen before include "Avidity" , "'Keenness, avidness (9)'" , "Keenness, enthusiasm" , "Keen attitude" , "Keen interest" .)