Animal found in fertile western region (3)
I believe the answer is:
ewe
'animal' is the definition.
(I've seen this before)
'in fertile western region' is the wordplay.
'in' indicates the answer is hidden within the clue.
'EWE' is hidden within 'fertile western region'.
'found' acts as a link.
(Other definitions for ewe that I've seen before include "Wool producer" , "Female on farm" , "Female animal" , "Lamb's dam" , "She'll provide material to knit" .)