Blackbirds mob owls with high, hysterical twittering, but switch to a low "tuk, tuk" whenever they see a ground predator such as a fox, cat or stoat. Wrens tick like alarm clocks if they detect that kind of prowler, and a cock pheasant which persists in giving off single calls has almost certainly spotted a fox. Jays, on the other hand, screech indiscriminately at all enemies, whether grounded or airborne.
Male deer generally remain silent, except during the annual rut; but females give hoarse barks when they see or scent danger, and the alarm call of a fallow doe, for example, will communicate itself to a roe or a muntjac. Humans, in other words, can glean much information about events in the countryside purely by listening.Reuse content