title: Seasonal patterns in the orientation system of the migratory ant Pachycondyla marginata.
abstract: Route directions of migrations by the neotropical termite-hunting ant Pachycondyla marginata at a forest reserve in Southeast Brazil were analysed by circular statistic. Colony movement patterns were compared between the rainy/hot and dry/cold seasons. Migrations during the dry/cold season are significantly oriented 13 degrees with the magnetic North-South axis, while rainy/hot migrations do not exhibit a preferred direction. This result is discussed considering the hypothesis that P. marginata ants may use the geomagnetic field as an orientation cue for migrations in the dry/cold season. The presence of magnetic iron oxides in the head and abdomen of P. marginata is consistent with this suggestion.
authors.affiliation: Centro Brasileiro de Pesquisas Físicas, Rua Xavier Sigaud 150, 22290-180, Rio de Janeiro, RJ, Brazil. darci@cbpf.br
authors.forename: D
authors.initials: D
authors.lastname: Acosta-Avalos
authors.forename: D M
authors.initials: DM
authors.lastname: Esquivel
authors.forename: E
authors.initials: E
authors.lastname: Wajnberg
authors.forename: H G
authors.initials: HG
authors.lastname: de Barros
authors.forename: P S
authors.initials: PS
authors.lastname: Oliveira
authors.forename: I
authors.initials: I
authors.lastname: Leal
mesh_terms: D000818:Animals; D001000:Ants / Q000502:physiology*; D001938:Brazil; D003080:Cold Temperature; D055593:Geological Phenomena; D005844:Geology; D006358:Hot Temperature; D008280:Magnetics; D009949:Orientation / Q000502:physiology*; D011891:Rain; D012621:Seasons