Without their swarming flocks, the pigeons also may have had trouble competing with other birds for nest sites, and nest sites may have been fewer as the deciduous forests were cut down.
(the pigeons; may have had; trouble competing with other birds for nest sites) (nest sites; may have been; fewer; T:as the deciduous forests were cut down) (the deciduous forests; were cut down; )
the pigeons nest sites the deciduous forests
may have had may have been were cut down
trouble competing with other birds for nest sites
fewer T:as the deciduous forests were cut down