DOI: 10.5061/dryad.j6s47
title: Data from: Flap or soar? How a flight generalist responds to its aerial environment

description: 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.
description: Lesser black-backed gull
 gps tracks with behaviour and weather dataThis dataset contains
 gps tracking and accelerometer data of 18 adult lesser black-backed gulls
 on Texel (the Netherlands) during their breeding season, using UvA-BiTS
 tags [1]. The gps data is enriched with with behaviour and weather
 data.The behaviour has been predicted by a classification model using
 accelerometer data (the approach is detailed in [2]). The weather data is
 derived from the ERA-Interim dataset [3] by interpolating towards the
 gps-points. The data fall in the time-window May 15 00:00:00 until June 15
 00:00:00 of the years 2012, 2013 and 2014 (i.e. within the breeding season
 for this population). The data have a resolution of 5 minutes, but data
 coverage over the time-window is incomplete (the set does not contain a
 record at every 5-minute interval over the time-window) because at some
 instances either accelerometer or weather data were not available. The
 data set comprises a collection of five different file types: 1. gps data
 (gps.zip); 2. accelerometer data (acc.zip); 3. expert labelled
 accelerometer data (ela.zip); 4. morphometric details of the individual
 birds (mor.csv); 5. photos to illustrate the attachment of the UvA-BiTS
 tags on the birds, as well as the direction of the 3 accelerometer-axes
 relative to the orientation of the tags (photos.pdf). File types 1 to 4
 are simple rectangular tables, stored in a comma-separated value (csv)
 format, starting with a header row. In a readme file (text-file, markdown
 formatted) additional information is given and the contents of the
 different file types are explained. For an easy transfer gps.zip, acc.zip,
 ela.zip, mor.csv and photos.pdf are combined into a sinlge file:
 gab.zip.gab.zip