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
Jantine	yahn-TEE-nə	Dutch
ÉDouard	e-DWAHR	French
Auda	-	Ancient Germanic
&Thorn;ÓRbjÖRn	-	Ancient Scandinavian
Dimitra	-	Greek
Denton	DEN-tən	English