To capture, to take possession of, to seize, to appropriate.
Use:
'There's no shaking them off 'til they've collared a good portion.'
'There's no shaking them off 'til they've appropriated a good portion.' (Murphy)
Derivation:
English 'to seize' from Old French 'Colier' and Latin 'Collars'. (Concise Oxford Dictionary) and note 'To collar one is to seize by the collar, to appropriate without leave.' (Brewer)