AbstractGoshawks and pygmy owls responded to recordings of passerine alarm calls by correctly orienting to their source. The seeet, or “aerial predator” alarm call which is generally assumed to be “non‐localizable”, while it elicited fewer responses than did mobbing calls, was nevertheless accurately localized by all birds that did respond. The evolution of alarm calls is discussed in terms of efficient prey communication, following Darwin's “antithesis principle”, rather than predator selection for non‐localizability.