Orientation of nocturnally migrating Swainson's thrush at dawn and dusk: Importance of energetic condition and geomagnetic cues
Sandberg, Roland LU ; Moore, FR ; Bäckman, Johan LU
and Lohmus, M
(2002)
In The Auk
119(1).
p.201-209
- Abstract
- We studied the early morning cage orientation of nocturnally migrating Swainson's Thrushes (Catharus ustulatus) during three fall migration seasons. The results were compared with earlier free-flight release tests under starry skies and were found to be consistent with continuation of migratory flights in the expected seasonally appropriate direction. Energetic condition proved decisive: fat birds chose directions in accordance with migration across the Gulf of Mexico, whereas lean birds oriented away from the coast, possibly in search of habitats suitable for refuelling. Whereas the orientation of fat Swainson's Thrushes was affected by experimental shifts of the magnetic field, the response during morning tests was larger than expected.... (More)
- We studied the early morning cage orientation of nocturnally migrating Swainson's Thrushes (Catharus ustulatus) during three fall migration seasons. The results were compared with earlier free-flight release tests under starry skies and were found to be consistent with continuation of migratory flights in the expected seasonally appropriate direction. Energetic condition proved decisive: fat birds chose directions in accordance with migration across the Gulf of Mexico, whereas lean birds oriented away from the coast, possibly in search of habitats suitable for refuelling. Whereas the orientation of fat Swainson's Thrushes was affected by experimental shifts of the magnetic field, the response during morning tests was larger than expected. A parallel series of orientation cage experiments performed during evening twilight showed a response to deflected magnetic fields that was close to the expected shift, which suggests a difference in integration of directional information between early morning and evening twilight activity. However, within-individual response to deflected magnetic fields was of the same magnitude during both morning and evening tests. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/145633
- author
- Sandberg, Roland
LU
; Moore, FR
; Bäckman, Johan
LU
and Lohmus, M
- organization
- publishing date
- 2002
- type
- Contribution to journal
- publication status
- published
- subject
- in
- The Auk
- volume
- 119
- issue
- 1
- pages
- 201 - 209
- publisher
- Oxford University Press
- external identifiers
-
- wos:000174275200017
- scopus:0036118712
- ISSN
- 0004-8038
- language
- English
- LU publication?
- yes
- id
- 6c54e7cf-9489-43d0-b54a-c94bbef58435 (old id 145633)
- alternative location
- http://www.bioone.org/bioone/?request=get-document&issn=0004-8038&volume=119&issue=01&page=0201
- date added to LUP
- 2016-04-01 16:48:36
- date last changed
- 2022-01-28 22:17:45
@article{6c54e7cf-9489-43d0-b54a-c94bbef58435,
abstract = {{We studied the early morning cage orientation of nocturnally migrating Swainson's Thrushes (Catharus ustulatus) during three fall migration seasons. The results were compared with earlier free-flight release tests under starry skies and were found to be consistent with continuation of migratory flights in the expected seasonally appropriate direction. Energetic condition proved decisive: fat birds chose directions in accordance with migration across the Gulf of Mexico, whereas lean birds oriented away from the coast, possibly in search of habitats suitable for refuelling. Whereas the orientation of fat Swainson's Thrushes was affected by experimental shifts of the magnetic field, the response during morning tests was larger than expected. A parallel series of orientation cage experiments performed during evening twilight showed a response to deflected magnetic fields that was close to the expected shift, which suggests a difference in integration of directional information between early morning and evening twilight activity. However, within-individual response to deflected magnetic fields was of the same magnitude during both morning and evening tests.}},
author = {{Sandberg, Roland and Moore, FR and Bäckman, Johan and Lohmus, M}},
issn = {{0004-8038}},
language = {{eng}},
number = {{1}},
pages = {{201--209}},
publisher = {{Oxford University Press}},
series = {{The Auk}},
title = {{Orientation of nocturnally migrating Swainson's thrush at dawn and dusk: Importance of energetic condition and geomagnetic cues}},
url = {{http://www.bioone.org/bioone/?request=get-document&issn=0004-8038&volume=119&issue=01&page=0201}},
volume = {{119}},
year = {{2002}},
}