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Flocking behaviour in the twilight ascents of Common Swifts Apus apus

Nilsson, Cecilia LU orcid ; Bäckman, Johan LU orcid and Dokter, Adriaan M. (2019) In Ibis 161(3). p.674-678
Abstract

Among the many unique flight behaviours of Common Swifts Apus apus, the most puzzling may be their ascents to high altitudes during both dusk and dawn. Twilight ascents have been hypothesized to be functionally related to information acquisition, including integration of celestial orientation cues, high-altitude visual landmarks and sampling of weather conditions. However, their exact purpose remains unknown. We tracked Common Swifts with tracking radar at their breeding grounds in southern Sweden, and present evidence that during the dusk ascent and dawn descent they often occur in flocks, whereas during the dusk descent and dawn ascent phase they do not. This flocking behaviour suggests that swifts may benefit from conspecific... (More)

Among the many unique flight behaviours of Common Swifts Apus apus, the most puzzling may be their ascents to high altitudes during both dusk and dawn. Twilight ascents have been hypothesized to be functionally related to information acquisition, including integration of celestial orientation cues, high-altitude visual landmarks and sampling of weather conditions. However, their exact purpose remains unknown. We tracked Common Swifts with tracking radar at their breeding grounds in southern Sweden, and present evidence that during the dusk ascent and dawn descent they often occur in flocks, whereas during the dusk descent and dawn ascent phase they do not. This flocking behaviour suggests that swifts may benefit from conspecific interactions during twilight ascents and descents, possibly through more robust cue acquisition and information exchange in groups, or extending social behaviour also seen in screaming parties before dusk.

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Please use this url to cite or link to this publication:
author
; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
flight altitude, flight behaviour, screaming parties
in
Ibis
volume
161
issue
3
pages
674 - 678
publisher
Wiley-Blackwell
external identifiers
  • scopus:85060768868
ISSN
0019-1019
DOI
10.1111/ibi.12704
language
English
LU publication?
yes
id
6f84ae07-dda5-4729-b6b4-86d2e0894399
date added to LUP
2019-02-13 08:59:55
date last changed
2022-04-25 21:37:01
@article{6f84ae07-dda5-4729-b6b4-86d2e0894399,
  abstract     = {{<p>Among the many unique flight behaviours of Common Swifts Apus apus, the most puzzling may be their ascents to high altitudes during both dusk and dawn. Twilight ascents have been hypothesized to be functionally related to information acquisition, including integration of celestial orientation cues, high-altitude visual landmarks and sampling of weather conditions. However, their exact purpose remains unknown. We tracked Common Swifts with tracking radar at their breeding grounds in southern Sweden, and present evidence that during the dusk ascent and dawn descent they often occur in flocks, whereas during the dusk descent and dawn ascent phase they do not. This flocking behaviour suggests that swifts may benefit from conspecific interactions during twilight ascents and descents, possibly through more robust cue acquisition and information exchange in groups, or extending social behaviour also seen in screaming parties before dusk.</p>}},
  author       = {{Nilsson, Cecilia and Bäckman, Johan and Dokter, Adriaan M.}},
  issn         = {{0019-1019}},
  keywords     = {{flight altitude; flight behaviour; screaming parties}},
  language     = {{eng}},
  month        = {{01}},
  number       = {{3}},
  pages        = {{674--678}},
  publisher    = {{Wiley-Blackwell}},
  series       = {{Ibis}},
  title        = {{Flocking behaviour in the twilight ascents of Common Swifts Apus apus}},
  url          = {{http://dx.doi.org/10.1111/ibi.12704}},
  doi          = {{10.1111/ibi.12704}},
  volume       = {{161}},
  year         = {{2019}},
}