An exaltation of larks
A bouquet of pheasants
A building of rooks
A cast of hawks (or falcons)
A charm of finches
A cover of coots
A deceit of lapwings
A descent of woodpeckers
A dissimulation of birds
A dole of doves
A murmuration of starlings
A murder of crows
An ostentation of peacokcs
A parliament of owls
A pitying of turtledoves
For more, see http://www.bcpl.net/~tross/gnlist.html and http://www.sentex.net/~tntcomm/kwfn/numbers.htm