Bikkurim, Chapter Three, Mishnah Five
The birds [tied to] the basket were [offered] as whole burnt-offerings, and those which they held in their hands they gave to the priests.
Along with the baskets of fruit and other produce that they brought to the Temple, to augment their gifts, they would also bring some birds, both for use as sacrifices and to serve as gifts to the priests. Some of the birds were tied to the baskets; these would be offered as whole burnt offerings, but those brought by hand were given simply as gifts to the priests. Bon Appetit priests!