The dynamics of the Peregrine hunts at Samish are quite different this year, especially since the recent flooding. There appear to be only 2 falcons this year thus far, an adult and a late phase juvenile, and they hunt independently. The juvenile may be the same one as last year, but this adult has a different style, and may be a different bird.
This year the Dunlin are more scattered, and farther from the road in private property. Last year the adult falcons appeared out of the sun, just off ground level, frequently simultaneously; the chase was short and circular, never going far from the road or the photographers. When the Dunlin are approached at low level by falcons, harriers, or eagles, they bunch together in very tightly packed formations that move as a single organism. This adult falcon (at least this day) hunted from 300-400 feet up. The Dunlin seemed to panic when it appeared far overhead and scattered in all directions even before it stooped. The falcon would then tuck it's wings and plummet vertically, covering the distance in 2-3 seconds in a classic Peregrine stoop that I had never seen before. It was impossible to see what happened after the falcon reached the flock.
The juvenile approached at tree top level, gaining neither stealth or speed, chasing them for up to a few miles.