title: Brain regions associated with visual cues are important for bird migration.
abstract: Long-distance migratory birds have relatively smaller brains than short-distance migrants or residents. Here, we test whether reduction in brain size with migration distance can be generalized across the different brain regions suggested to play key roles in orientation during migration. Based on 152 bird species, belonging to 61 avian families from six continents, we show that the sizes of both the telencephalon and the whole brain decrease, and the relative size of the optic lobe increases, while cerebellum size does not change with increasing migration distance. Body mass, whole brain size, optic lobe size and wing aspect ratio together account for a remarkable 46% of interspecific variation in average migration distance across bird species. These results indicate that visual acuity might be a primary neural adaptation to the ecological challenge of migration.
authors.affiliation: MTA-DE 'Lendület' Behavioural Ecology Research Group, Department of Evolutionary Zoology and Human Biology, University of Debrecen, Egytem tér 1, 4032, Debrecen, Hungary Evolutionary Ecology Group, Hungarian Department of Biology and Ecology, Babeş-Bolyai University, Clinicilor Street 5-7, 400006, Cluj-Napoca, Romania orsolya.vincze@vocs.unideb.hu.
authors.forename: Orsolya
authors.initials: O
authors.lastname: Vincze
authors.affiliation: MTA-DE 'Lendület' Behavioural Ecology Research Group, Department of Evolutionary Zoology and Human Biology, University of Debrecen, Egytem tér 1, 4032, Debrecen, Hungary Evolutionary Ecology Group, Hungarian Department of Biology and Ecology, Babeş-Bolyai University, Clinicilor Street 5-7, 400006, Cluj-Napoca, Romania.
authors.forename: Csongor I
authors.initials: CI
authors.lastname: Vágási
authors.affiliation: MTA-DE 'Lendület' Behavioural Ecology Research Group, Department of Evolutionary Zoology and Human Biology, University of Debrecen, Egytem tér 1, 4032, Debrecen, Hungary Evolutionary Ecology Group, Hungarian Department of Biology and Ecology, Babeş-Bolyai University, Clinicilor Street 5-7, 400006, Cluj-Napoca, Romania.
authors.forename: Péter L
authors.initials: PL
authors.lastname: Pap
authors.affiliation: MTA-DE 'Lendület' Behavioural Ecology Research Group, Department of Evolutionary Zoology and Human Biology, University of Debrecen, Egytem tér 1, 4032, Debrecen, Hungary Evolutionary Ecology Group, Hungarian Department of Biology and Ecology, Babeş-Bolyai University, Clinicilor Street 5-7, 400006, Cluj-Napoca, Romania Museum of Zoology, Babeş-Bolyai University, Clinicilor Street 5-7, 400006, Cluj-Napoca, Romania.
authors.forename: Gergely
authors.initials: G
authors.lastname: Osváth
authors.affiliation: Laboratoire d'Ecologie, Systématique et Evolution, CNRS UMR 8079, Université Paris-Sud, Bâtiment 362, 91405 Orsay Cedex, France.
authors.forename: Anders Pape
authors.initials: AP
authors.lastname: Møller
mesh_terms: D025041:Animal Migration; D000818:Animals; D001717:Birds / Q000033:anatomy & histology* / Q000502:physiology; D001835:Body Weight; D001921:Brain / Q000033:anatomy & histology* / Q000502:physiology; D002531:Cerebellum / Q000502:physiology; D003463:Cues; D005426:Flight, Animal; D009899:Optic Lobe, Nonmammalian / Q000502:physiology; D009929:Organ Size; D009949:Orientation; D013687:Telencephalon / Q000502:physiology; D014921:Wings, Animal / Q000033:anatomy & histology
keywords: brain mass; cerebellum; migration distance; neuroecology; optic lobe; telencephalon