Portland's swifts abandon Chapman Elementary's chimney

It appears to be a wrap on the Vaux's swifts bird's 30-year tenure roosting inside Chapman Elementary's chimney during their journey south.

• Not a single bird was seen swirling around the landmark on a recent September evening.

Zoom in: Some "swifitie" aficionados speculate their disappearance is due to human activity — whether it be knuckleheads flying drones near the mouth of the chimney or the party-like atmosphere on the hill below.

Yes, but: The swifts have not given up on Portland entirely. They've been spotted roosting in other chimneys in the city, but the Bird Alliance of Oregon has not publicized where.

• You can guess why.