Bishop is working for endangered European animal (5)
I believe the answer is:
bison
'endangered european animal' is the definition.
'bison' can be an answer for 'animal' (I've seen this before). I'm not certain of the 'endangered european' bit.
'bishop is working' is the wordplay.
'bishop' becomes 'B' (abbreviation for bishop in chess).
'working' becomes 'on' (on can mean working or activated).
'b'+'is'+'on'='BISON'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for bison that I've seen before include "Buffalo Bill's prey" , "Wild cow" , "US wild ox" , "Large shaggy wild ox" , "It's a buffalo in America" .)