title: Flap or soar? How a flight generalist responds to its aerial environment.
abstract: The aerial environment is heterogeneous in space and time and directly influences the costs of animal flight. Volant animals can reduce these costs by using different flight modes, each with their own benefits and constraints. However, the extent to which animals alter their flight modes in response to environmental conditions has rarely been studied in the wild. To provide insight into how a flight generalist can reduce the energetic cost of movement, we studied flight behaviour in relation to the aerial environmental and landscape using hundreds of hours of global positioning system and triaxial acceleration measurements of the lesser black-backed gull (Larus fuscus). Individuals differed largely in the time spent in flight, which increased linearly with the time spent in flight at sea. In general, flapping was used more frequently than more energetically efficient soaring flight. The probability of soaring increased with increasing boundary layer height and time closer to midday, reflecting improved convective conditions supportive of thermal soaring. Other forms of soaring flight were also used, including fine-scale use of orographic lift. We explore the energetic consequences of behavioural adaptations to the aerial environment and underlying landscape and implications for individual energy budgets, foraging ecology and reproductive success.This article is part of the themed issue 'Moving in a moving medium: new perspectives on flight'.
authors.affiliation: Computational Geo-Ecology, IBED, University of Amsterdam, Science Park 904, 1090GE Amsterdam, The Netherlands shamoun@uva.nl.
authors.forename: Judy
authors.identifier: 0000-0002-1652-7646
authors.initials: J
authors.lastname: Shamoun-Baranes
authors.affiliation: Computational Geo-Ecology, IBED, University of Amsterdam, Science Park 904, 1090GE Amsterdam, The Netherlands.
authors.forename: Willem
authors.identifier: 0000-0002-5250-8872
authors.initials: W
authors.lastname: Bouten
authors.affiliation: Computational Geo-Ecology, IBED, University of Amsterdam, Science Park 904, 1090GE Amsterdam, The Netherlands.
authors.forename: E Emiel
authors.identifier: 0000-0002-8895-0427
authors.initials: EE
authors.lastname: van Loon
authors.affiliation: Netherlands eScience Center, Science Park 140, 1098 XG Amsterdam, The Netherlands.
authors.forename: Christiaan
authors.identifier: 0000-0002-5529-5761
authors.initials: C
authors.lastname: Meijer
authors.affiliation: Department Coastal Systems, NIOZ Royal Institute for Sea Research and Utrecht University, PO Box 59, 1790 AB Den Burg, Texel, The Netherlands.
authors.forename: C J
authors.identifier: 0000-0002-3469-9070
authors.initials: CJ
authors.lastname: Camphuysen
mesh_terms: D000818:Animals; D046091:Charadriiformes / Q000502:physiology*; D004734:Energy Metabolism; D004777:Environment; D005247:Feeding Behavior; D005426:Flight, Animal; D009426:Netherlands; D014921:Wings, Animal / Q000502:physiology*
keywords: GPS; accelerometer; foraging ecology; orographic lift; soar; thermal convection