Spotted flycatcher the cuckoo, but became so good at recognising the intruder's eggs that it ceased to be victimised. A contrast to this is the dunnock, which appears to be a recent cuckoo host, since it does not show any egg discrimination. A study conducted at two different locations in southern England found that one third of nests were predated. The Eurasian jay ("Garrulus glandarius") was the most common aerial predator, consuming both eggs and chicks. The domestic cat ("Felis catus") predated a small fraction of the nests. Spotted flycatcher The spotted flycatcher ("Muscicapa striata") is a small passerine bird in the
Preening (bird) preening. The conflict between two incompatible drives, such as incubating and escape, can also lead a bird to engage in displacement activities. Nesting Sandwich and common terns preen when they have been alarmed by a potential predator or when they have had an aggressive encounter with a neighboring bird, for instance. Fighting European starlings will break off their battles to preen. Although preening is primarily an individual behaviour, some species indulge in allopreening, with one individual preening another. It is not particularly common among birds, though species from at least 43 families are known to engage in the mutual activity.