Birds and pigs messed with lawn (8)
I believe the answer is:
lapwings
'birds' is the definition.
(lapwing is a kind of bird)
'pigs messed with lawn' is the wordplay.
'messed with' indicates an anagram.
'pigs' with its letters mixed up with 'lawn' makes 'LAPWINGS'.
'and' is the link.
(Other definitions for lapwings that I've seen before include "Types of plover" , "birds" , "Crested plovers" .)