Yes, two to the brace but partridge were traditionally counted in a leash which was three birds. Not often found now and usually counted in braces. Hounds of course are always counted in Couples.
If you can find a copy of a book called The Language of Sport by E.C.Hare first published in 1939 it explains these and many more. Loads of interesting terms covered. For instance the description of a male Fallow deer. 1st. year; a fawn, 2nd. year a Pricket, 3rd. year a Sorel, 4th. year a Sore, 5th. year Buck of the first head, 6th. year plus a Great Buck. Another way to bore your friends at dinner! Lagopus.....