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To combat the threat of predation, prey species have developed a variety of ways to recognize and respond appropriately to novel predators. While there is evidence that predator recognition does not require learning in certain species, learning appears to play an important role for other species. In systems where learning is important, it is less clear whether predator identification requires prior experience with specific predators or, whether general experience with predators provides sufficient tools for identifying similar species of novel predators. Here we test whether wild-living adult birds recognize a dangerous predator that occurs in only part of their geographical range. We presented taxidermy mounts of little owls, Athene noctua, and sparrowhawks, Accipiter nisus, to blue tits, Cyanistes caeruleus, and great tits, Parus major. All populations of both tit species co-occur with sparrowhawks, but populations differ in their prior experience with little owls. We found that tits that overlap geographically with little owls responded to little owls using the same intensity of mobbing behaviour exhibited toward sparrowhawks. In populations with no historical contact with little owls, however, both blue and great tits treated little owls as a lower threat than sparrowhawks. These results suggest that blue tits and great tits do not generalize ‘predatory features’ to novel predators and instead need prior experience with specific predators before they assign the correct level of threat.

(1950). LXXII.—Note on the common European earwig, Forficula auricularia Linn. (Dermaptera) as food of the little Owl, Athene noctua vidalii Brehm. Annals and Magazine of Natural History: Vol. 3, No. 33, pp. 775-776.

EXTRAORDINARILY little is known of the process of extension and contraction of range which many animal species periodically undergo. Among British birds, the only two the extension of range of which during the past hundred years has been at all adequately described are the little owl (Athene, noctua vidalii)1, an introduced species, and the fulmar petrel (Fulmarus g. glacialis)2.

The role of ringing recovery patterns as indicators of periods of stress and mortality is assessed in four small birds of prey. In first year birds the main period of mortality occurs when the young leave the nest and/or become independent of the parents: Barn Owl Tyto alba September, Little Owl Athene noctua July-August, Tawny Owl Strix aluco August-October, Sparrowhawk Accipiter nisus August-September. The proportion of birds accidentally killed was consistently higher in first year than adult birds. In adult birds, stress associated with breeding was most pronounced in the Little Owl (May-June), Sparrowhawk (May-July), Tawny Owl (March-July) and to a lesser extent in the Barn Owl (July-October) where the majority of birds were recovered during the late winter (January-April).