Approximately 87 percent of the midwestern pairs and 33 percent of the eastern pairs are nesting on manmade structures: bridges, buildings and smokestacks (Martell and McNicoll 1999).
(Approximately 87 percent of the midwestern pairs and 33 percent of the eastern pairs; are nesting; on manmade structures)
Approximately 87 percent of the midwestern pairs and 33 percent of the eastern pairs
are nesting
on manmade structures