Bird goes savage protecting egg (5)
I believe the answer is:
goose
'bird' is the definition.
(goose is a kind of bird)
'goes savage protecting egg' is the wordplay.
'savage' is an anagram indicator (to savage can mean to attack or destroy).
'protecting' means one lot of letters goes inside another.
'egg' becomes 'o' (I've seen this in other clues).
'goes' is an anagram of 'gose'.
'gose' placed around 'o' is 'GOOSE'.
(Other definitions for goose that I've seen before include "Bird - tailor's iron" , "Christmas bird?" , "Web-footed long-necked bird" , "Gander's mate" , "Grab seat" .)