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Nocturnal passerine migrants fly faster in spring than in autumn: a test of the time minimization hypothesis

Karlsson, Håkan LU ; Nilsson, Cecilia LU ; Bäckman, Johan LU and Alerstam, Thomas LU (2012) In Animal Behaviour 83(1). p.87-93
Abstract
It has been suggested that time selection and precedence in arrival order are more important during spring than autumn migration. Migrating birds are expected to fly at faster airspeeds if they minimize duration rather than energy costs of migration, and they are furthermore expected to complete their journeys by final sprint flights if it is particularly important to arrive at the destination before competitors. We tested these hypotheses by tracking-radar studies of nocturnal passerine migrants during several spring and autumn seasons at Lund (56 degrees N) and Abisko (68 degrees N) at the southern and northern ends of the Scandinavian Peninsula, respectively. The samples from these two sites represent migrants that are mostly rather far... (More)
It has been suggested that time selection and precedence in arrival order are more important during spring than autumn migration. Migrating birds are expected to fly at faster airspeeds if they minimize duration rather than energy costs of migration, and they are furthermore expected to complete their journeys by final sprint flights if it is particularly important to arrive at the destination before competitors. We tested these hypotheses by tracking-radar studies of nocturnal passerine migrants during several spring and autumn seasons at Lund (56 degrees N) and Abisko (68 degrees N) at the southern and northern ends of the Scandinavian Peninsula, respectively. The samples from these two sites represent migrants that are mostly rather far from (Lund) or close to (Abisko) their breeding destinations. We found that the birds were flying at clearly faster airspeeds in spring than in autumn at both study sites, with spring speeds exceeding autumn speeds by, on average, 16%, after taking effects of wind conditions and vertical flight speeds into account. This difference in speeds could not be explained by seasonal differences in body mass or wing morphology and thus supports the hypothesis of time-selected spring migration. There was also a significantly larger seasonal difference in airspeed at Abisko than at Lund, suggesting that the birds may have shown an inclination to sprint on their final spring flights to the breeding destinations, although this possible extra sprint effort was modest. (C) 2011 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
airspeed, autumn migration, bird migration, flight speed, optimal, migration, passerine, spring migration
in
Animal Behaviour
volume
83
issue
1
pages
87 - 93
publisher
Elsevier
external identifiers
  • wos:000298149900014
  • scopus:83555165029
ISSN
1095-8282
DOI
10.1016/j.anbehav.2011.10.009
language
English
LU publication?
yes
id
f01eda19-561b-4564-8bdf-e49c4298e760 (old id 2358417)
date added to LUP
2012-02-24 08:30:24
date last changed
2017-10-01 03:05:23
@article{f01eda19-561b-4564-8bdf-e49c4298e760,
  abstract     = {It has been suggested that time selection and precedence in arrival order are more important during spring than autumn migration. Migrating birds are expected to fly at faster airspeeds if they minimize duration rather than energy costs of migration, and they are furthermore expected to complete their journeys by final sprint flights if it is particularly important to arrive at the destination before competitors. We tested these hypotheses by tracking-radar studies of nocturnal passerine migrants during several spring and autumn seasons at Lund (56 degrees N) and Abisko (68 degrees N) at the southern and northern ends of the Scandinavian Peninsula, respectively. The samples from these two sites represent migrants that are mostly rather far from (Lund) or close to (Abisko) their breeding destinations. We found that the birds were flying at clearly faster airspeeds in spring than in autumn at both study sites, with spring speeds exceeding autumn speeds by, on average, 16%, after taking effects of wind conditions and vertical flight speeds into account. This difference in speeds could not be explained by seasonal differences in body mass or wing morphology and thus supports the hypothesis of time-selected spring migration. There was also a significantly larger seasonal difference in airspeed at Abisko than at Lund, suggesting that the birds may have shown an inclination to sprint on their final spring flights to the breeding destinations, although this possible extra sprint effort was modest. (C) 2011 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.},
  author       = {Karlsson, Håkan and Nilsson, Cecilia and Bäckman, Johan and Alerstam, Thomas},
  issn         = {1095-8282},
  keyword      = {airspeed,autumn migration,bird migration,flight speed,optimal,migration,passerine,spring migration},
  language     = {eng},
  number       = {1},
  pages        = {87--93},
  publisher    = {Elsevier},
  series       = {Animal Behaviour},
  title        = {Nocturnal passerine migrants fly faster in spring than in autumn: a test of the time minimization hypothesis},
  url          = {http://dx.doi.org/10.1016/j.anbehav.2011.10.009},
  volume       = {83},
  year         = {2012},
}