10.5061/DRYAD.K0P2NGF6T
Syposz, Martyna
0000-0002-6148-039X
University of Oxford
Padget, Oliver
University of Oxford
Wynn, Joe
University of Oxford
Gillies, Natasha
0000-0002-9950-609X
University of Oxford
Fayet, Annette
University of Oxford
Guilford, Tim
University of Oxford
Data from: An assay to investigate factors influencing initial orientation
in nocturnally fledging seabirds.
Dryad
dataset
2020
FOS: Natural sciences
dataset
weather data
2020-11-19T00:00:00Z
2020-11-19T00:00:00Z
en
64721 bytes
2
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
The first solitary migration of juvenile birds is difficult to study
because of a low juvenile survival rates and sometimes long delays in
return to the breeding grounds. Consequently, little is known about this
crucial life event for many bird species, in particular the sensory
guidance mechanisms facilitating the first migratory journey. Initial
orientation during the first migration is a key measure to investigate
these mechanisms. Here, we developed an assay to measure initial
orientation as flight direction upon first take-off in nocturnally
fledging juvenile seabirds. We dorsally deployed a coloured LED on
juvenile birds to allow researchers to observe the vanishing bearings of
individuals as they flew out to sea. Additionally, we co-deployed either a
small Neodymium magnet or glass bead (control) on top of the bird’s head
to investigate the use of magnetoreception, previously unexplored in this
early life stage. We used this assay to observe the first flight of Manx
shearwaters (Puffinus puffinus) and found that they did not orient towards
their wintering ground straight after taking off. Further, we did not find
an effect of the magnetic treatment on juveniles’ flight direction, though
whether this is due to the birds not using magnetoreception, other salient
cues being available or a lack of motivation to orient to the migratory
beeline is unclear. We were, however, able to identify wind direction and
topography as drivers of first flight direction in Manx shearwaters, which
fledged with wind component between a crosswind and a tailwind and
directed their maiden flight towards the sea and away from the land.
This novel assay will facilitate the study of the maiden flight of
nocturnally fledging birds and will help advance the study of sensory
guidance mechanisms underpinning migratory orientation in a wide range of
taxa, including species which are traditionally challenging to study.