title: Alternate non-stop migration strategies of pied flycatchers to cross the Sahara desert.
abstract: Each year more than two billion songbirds cross the Sahara, but how they perform this formidable task is largely unknown. Using geolocation tracks from 27 pied flycatchers, a nocturnally migrating passerine, we show that most birds made diurnal flights in both autumn and spring. These diurnal flights were estimated to be part of non-stop flights of mostly 40-60 h. In spring, birds flew across the Sahara, while autumn migration probably circumpassed part of the desert, through a long oversea flight. Our data contradict claims that passerines cross the Sahara by intermittent flight and daytime resting. The frequent occurrence of long non-stop flights to cross the desert shows migrants' physiological abilities and poses the question why this would not be the general migration strategy to cross the Sahara.
authors.affiliation: Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences, University of Groningen, PO Box 11103, Groningen 9700 CC, The Netherlands janneouwehand@gmail.com.
authors.forename: Janne
authors.identifier: http://orcid.org/0000-0003-2573-6287
authors.initials: J
authors.lastname: Ouwehand
authors.affiliation: Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences, University of Groningen, PO Box 11103, Groningen 9700 CC, The Netherlands.
authors.forename: Christiaan
authors.initials: C
authors.lastname: Both
mesh_terms: D000352:Africa, Northern; D025041:Animal Migration; D000818:Animals; D005260:Female; D005426:Flight, Animal; D040362:Geographic Information Systems; D008297:Male; D046109:Passeriformes / Q000502:physiology*; D012621:Seasons; D013997:Time Factors
keywords: Afro-Palaearctic passerine; Ficedula hypoleuca; Sahara desert; fuelling; migration strategy