What is the name of a group of mallard ducks?

There are many species of duck.

Heavy-

Pekin (Aflac duck)

Aylesbury

Rouen (Large Mallard)

Muscovy

Silver Appleyard

Saxony

Medium-

Ancona

Cayuga

Blue Swedish

Buff

Hookbill

Light-

Indian Runner Ducks

Khaki Campbell Ducks