The flock that ranges across the northeastern neighborhoods has been using this stretch more visibly in recent weeks, according to a handful of residents who track the birds informally online. The Vallejo stairway corridor, with its dense plantings of fruiting trees and the relative quiet of the surrounding blocks, seems to pull them in the way certain corners pull in regulars — reliably, for reasons that make sense if you know the place.

The conures are not native, which anyone who has heard them will have gathered; they arrived decades ago through the pet trade, escaped or released, and have been threading through the hills ever since. The flock fluctuates in size and territory depending on the season and what's fruiting where. Some residents track their movements the way others track which coffee shop has a table open — practically, with a little pleasure in the knowing.