passage bird造句

• The numbers of some passage birds depend on weather conditions.
• It is an internationally preserved habitat for rare passage birds.
• Its exact status as a passage bird in countries such as Venezuela is therefore uncertain.
• The Northeastern Crane Network was organized as a protection strategy of Asian and Pacific passage birds at the 6th Ramsar Convention conference in 1996.
• In August, the gatherings at the nightly roost increase enormously, though the advent and departure of passage birds causes great irregularity in numbers.