Every autumn in Portland, Oregon, hundreds of people flock in the evening to the Chapman Elementary School, a beautiful small campus in a quaint neighborhood. They come with their floor mats and their wine and their picnic dinners, all to stare at the school's big chimney.

Not just the chimney, but the congregation of Vaux's swifts, which come to Oregon from Central America and Venezuala in the spring to breed and rear their young. Now, in the fall, up to 45,000 of them congregate around the chimney, preparing for their migration back to Latin America.

That so many of them can fit into this chimney is spectacular, but the antics of thousands of these tiny birds in sync each evening in unbelievable. They circle in increasing numbers around the chimney. The crowd - tonight is the highest attendance ever - about 3,500 people - claps in anticipation of the first swifts diving into the chimney.

The swift's entry into the chimney continues to amaze people as they start to create funneling - tornado shapes in the sky - more ooohs and ahhhs. But the audience doesn't quite know what to think when a peregrine falcon appears in the sky, bulleting towards the funneling birds.

Peregrine falcons have their own history in Portland. The species fell into decline worldwide after the widespread use of DDT as a pesticide. Peregrines became almost completely extirpated from the 48 states - but the endangered species act, and the banning of DDT started to give them a chance. Cities like Portland poured over efforts to rehabilitate the urban populations of the species. Now, they thrive here, to the city's delight.

But now, in this moment of drama, there are sighs of horror, a few shrill screams. The peregrine dives - they say peregrine's are the fastest animal in the world, attacking by dive bombing at over 200 miles per hour. He pours through thousands of birds - and misses. The crowd cheers in a roar, even though, maybe, they like peregrine falcons more than vaux's swifts. Again, the peregrine dives, and again he misses. The crowd cheers.

But then something unusual happens. About a thousand of the swifts regroup and start chasing after the peregrine. The follow him for several miles, until, finally, he outruns them and fades into the cityscape.

The crowd continues to delight in the swifts. Evening turns to night and only a few thousand remain in the sky. Surprising thousands in the audience, the peregrine returns, almost falling from the sky. He efficiently grabs a swift, and leaves. The crowd boos in awe.

Seeing this all for the first time is rewarding - is there something wrong with watching animals killing animals? Is there something wrong with saving the Peregrine falcon, which kills swifts? The questions seem silly, but they are certainly on my mind as we watch the swifts.

These questions are very much on my mind, because of the man from Galveston.