PORTLAND, Ore. (KOIN) — The swifts have returned to Chapman Elementary School.

Since the 1980s, Vaux’s Swifts have been coming to Oregon from Central America and Venezuela in late April. But in September, they make the return trip.

The birds, which the Audobon Society of Portland describes as “small, dark, fast-flying cigars with wings,” return to the same roosting spots each year. In Portland, that spot is the chimney at Chapman Elementary, 1445 NW 26th Ave.

Watch parties are set for each night in September, beginning about an hour before sunset. People bring chairs or sit on the school lawn or in nearby Wallace Park to watch the birds gather, circle and dive into the chimney. There the birds sleep for the night.