at roost造句

Birds can be directly counted on breeding colonies, and at roosts, migration bottlenecks.
These are not particularly gregarious birds and are seldom seen in large flocks except at roosts.
Counts are made in the evening as parrots arrive at roost patches and in the following morning as the parrots leave.
Most bats are preyed on by owls as they fly and by snakes at roosts . ( Bonaccorso, 1998; Phillips, 1980)
It's difficult to see at roost in a sentence. 用at roost造句挺难的