be (one's) pigeon

To be one's area of expertise or responsibility. Primarily heard in UK, Australia. I can't approve expense reports, but Betty can—that's her pigeon.

Name	Pronounced	Usage
Aaron	['ɛərən]
Jefimija	-	Serbian
Trevor	TRE-vər (English)	Welsh, English
Jinny	JIN-ee	English
Saturn	SA-tərn (English)	Roman Mythology (Anglicized)
Virgee	VUR-jee	English