Desert crossing strategies of migrant songbirds vary between and within species

Frédéric Jiguet (1) , Malcolm Burgess , Kasper Thorup , Greg Conway , José Luis Arroyo Matos , Lee Barber , John Black , Niall Burton , Joan Castelló , Gary Clewley , José Luis Copete , Michel Alexandre Czajkowski , Svein Dale , Tony Davis , Valery Dombrovski , Mike Drew , Jaanus Elts , Vicky Gilson , Emilienne Grzegorczyk (1) , Ian Henderson , Michael Holdsworth , Rob Husbands , Romain Lorrilliere (1) , Riho Marja , Tuomas Seimola , Simonas Minkevicius , Caroline Moussy (1) , Peter Olsson , Alejandro Onrubia , Marc Perez , Joseph Piacentini , Markus Piha , Jean-Marc Pons (2) , Petr Procházka , Marko Raković , Harriet Robins , Gunnar Selstam , Michał Skierczyński , Jan Sondell , Jean-Claude Thibault (2) , Anders P. Tøttrup , Justin Walker , Chris Hewson

1 CESCO - Centre d'Ecologie et des Sciences de la COnservation
2 ISYEB - Institut de Systématique, Evolution, Biodiversité

Each year, billions of songbirds cross large ecological barriers during their migration. Understanding how they perform this incredible task is crucial to predict how global change may threaten the safety of such journeys. earlier studies based on radar suggested that most songbirds cross deserts in intermittent flights at high altitude, stopping in the desert during the day, while recent tracking with light loggers suggested diurnal prolongation of nocturnal flights and common non-stop flights for some species. We analyzed light intensity and temperature data obtained from geolocation loggers deployed on 130 individuals of ten migratory songbird species, and show that a large variety of strategies for crossing deserts exists between, but also sometimes within species. Diurnal stopover in the desert is a common strategy in autumn, while most species prolonged some nocturnal flights into the day. Nonstop flights over the desert occurred more frequently in spring than in autumn, and more frequently in foliage gleaners. Temperature recordings suggest that songbirds crossed deserts with flight bouts performed at various altitudes according to species and season, along a gradient ranging from low above ground in autumn to probably >2000 m above ground level, and possibly at higher altitude in spring. High-altitude flights are therefore not the general rule for crossing deserts in migrant songbirds. We conclude that a diversity of migration strategies exists for desert crossing among songbirds, with variations between but also within species.

Domaines: Ecologie, Environnement

Frédéric Jiguet, Malcolm Burgess, Kasper Thorup, Greg Conway, José Luis Arroyo Matos, et al.. Desert crossing strategies of migrant songbirds vary between and within species. Scientific Reports, 2019, 9, pp.20248. ⟨10.1038/s41598-019-56677-4⟩. ⟨mnhn-02552949⟩