title: Ultra-Rapid Vision in Birds.
abstract: Flying animals need to accurately detect, identify and track fast-moving objects and these behavioral requirements are likely to strongly select for abilities to resolve visual detail in time. However, evidence of highly elevated temporal acuity relative to non-flying animals has so far been confined to insects while it has been missing in birds. With behavioral experiments on three wild passerine species, blue tits, collared and pied flycatchers, we demonstrate temporal acuities of vision far exceeding predictions based on the sizes and metabolic rates of these birds. This implies a history of strong natural selection on temporal resolution. These birds can resolve alternating light-dark cycles at up to 145 Hz (average: 129, 127 and 137, respectively), which is ca. 50 Hz over the highest frequency shown in any other vertebrate. We argue that rapid vision should confer a selective advantage in many bird species that are ecologically similar to the three species examined in our study. Thus, rapid vision may be a more typical avian trait than the famously sharp vision found in birds of prey.
authors.affiliation: Department of Animal Ecology, Uppsala University, Norbyvägen 18D, S-752 36, Uppsala, Sweden.
authors.forename: Jannika E
authors.initials: JE
authors.lastname: Boström
authors.affiliation: Department of Animal Ecology, Uppsala University, Norbyvägen 18D, S-752 36, Uppsala, Sweden.|Department of Zoology, Stockholm University, S-106 91, Stockholm, Sweden.
authors.forename: Marina
authors.initials: M
authors.lastname: Dimitrova
authors.affiliation: Department of Animal Ecology, Uppsala University, Norbyvägen 18D, S-752 36, Uppsala, Sweden.
authors.forename: Cindy
authors.initials: C
authors.lastname: Canton
authors.affiliation: Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Box 7011, S-750 07, Uppsala, Sweden.
authors.forename: Olle
authors.initials: O
authors.lastname: Håstad
authors.affiliation: Department of Animal Ecology, Uppsala University, Norbyvägen 18D, S-752 36, Uppsala, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Qvarnström
authors.affiliation: Department of Animal Ecology, Uppsala University, Norbyvägen 18D, S-752 36, Uppsala, Sweden.|Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Box 7011, S-750 07, Uppsala, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Ödeen
mesh_terms: D000818:Animals; D020304:Raptors / Q000502:physiology*; D014785:Vision, Ocular / Q000502:physiology*