Details

Autor(en) / Beteiligte

• Rutz, Christian

Titel

Predator Fitness Increases with Selectivity for Odd Prey

Ist Teil von

• Current biology, 2012-05, Vol.22 (9), p.820-824

Ort / Verlag

England: Elsevier Inc

Erscheinungsjahr

2012

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• The fundamental currency of normative models of animal decision making is Darwinian fitness. In foraging ecology, empirical studies typically assess foraging strategies by recording energy intake rates rather than realized reproductive performance [1]. This study provides a rare empirical link, in a vertebrate predator-prey system, between a predator's foraging behavior and direct measures of its reproductive fitness. Goshawks Accipiter gentilis selectively kill rare color variants of their principal prey, the feral pigeon Columba livia, presumably because targeting odd-looking birds in large uniform flocks helps them overcome confusion effects and enhances attack success [2–4]. Reproductive performance of individual hawks increases significantly with their selectivity for odd-colored pigeons, even after controlling for confounding age effects. Older hawks exhibit more pronounced dietary preferences, suggesting that hunting performance improves with experience [5, 6]. Intriguingly, although negative frequency-dependent predation by hawks exerts strong selection against rare pigeon phenotypes [7], pigeon color polymorphism is maintained through negative assortative mating [8]. ► Goshawks are agile bird hunters that, in cities, specialize on killing feral pigeons ► When under attack from raptors, pigeons seek safety in numbers (“selfish herd”) ► Hawks select odd-colored pigeons in flocks, to avoid confusion (“oddity effect”) ► Goshawks' reproductive performance increases with their selectivity for odd pigeons