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Complex timing of Marsh Harrier Circus aeruginosus migration due to pre- and post-migratory movements

Strandberg, Roine LU ; Klaassen, Raymond LU ; Hake, Mikael; Olofsson, Patrik; Thorup, Kasper and Alerstam, Thomas LU (2008) In Ardea 96(2). p.159-171
Abstract
We tracked three juvenile and 14 adult Marsh Harriers Circus aeruginosus

from southern Sweden via satellite to investigate migration strategies.

Four individuals were tracked for at least two years. All three juveniles

and four of the adults made west-oriented pre-migratory movements

well before the onset of autumn migration, and trans-Saharan

migrants visited post-migratory stopover areas in tropical Africa. By

these movements, the harriers presumably exploit short-term regional

variation in food abundance. Autumn and spring migration occurred in

a relatively narrow corridor, without distinct differences between sexes

in timing, speed, distance, and duration... (More)
We tracked three juvenile and 14 adult Marsh Harriers Circus aeruginosus

from southern Sweden via satellite to investigate migration strategies.

Four individuals were tracked for at least two years. All three juveniles

and four of the adults made west-oriented pre-migratory movements

well before the onset of autumn migration, and trans-Saharan

migrants visited post-migratory stopover areas in tropical Africa. By

these movements, the harriers presumably exploit short-term regional

variation in food abundance. Autumn and spring migration occurred in

a relatively narrow corridor, without distinct differences between sexes

in timing, speed, distance, and duration of migration, except that

females tended to migrate faster in spring than did males. Juveniles

migrated shorter distances than adults, and migration speeds were

lower. Spring migration was similar to autumn migration in terms of

speed and duration. Juveniles did not cross the Sahara Desert and three

birds, one female and two juveniles, wintered in Europe, which is in

accordance with a recent increase in the number of (juvenile) Marsh

Harriers wintering in northwestern Europe. All birds that crossed the

Sahara wintered in tropical West Africa. Harriers showed site fidelity to

breeding, wintering and stopover areas. The overall migration speed of

Marsh Harriers was similar to that of Ospreys Pandion haliaetus and

Honey Buzzards Pernis apivorus, two other trans-Saharan migrants.

Ospreys use fly-and-forage migration to promote resulting speed,

whereas Honey Buzzards are particularly apt to exploit thermal soaring.

How Marsh Harriers balance foraging versus travelling to accomplish

their rapid migration speeds remains to be resolved. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to specialist publication or newspaper
publication status
published
subject
keywords
Marsh Harrier, post-migratory movements, pre-migratory movements, satellite tracking, migration
categories
Popular Science
in
Ardea
volume
96
issue
2
pages
159 - 171
publisher
Nederlandse Ornithologische Unie
external identifiers
  • wos:000269623000002
  • scopus:56749185256
ISSN
0373-2266
language
English
LU publication?
yes
id
c189c8fa-c00c-46cd-a1a0-6073403ddbb8 (old id 1428708)
date added to LUP
2009-06-22 15:20:36
date last changed
2017-07-09 04:08:35
@misc{c189c8fa-c00c-46cd-a1a0-6073403ddbb8,
  abstract     = {We tracked three juvenile and 14 adult Marsh Harriers Circus aeruginosus<br/><br>
from southern Sweden via satellite to investigate migration strategies.<br/><br>
Four individuals were tracked for at least two years. All three juveniles<br/><br>
and four of the adults made west-oriented pre-migratory movements<br/><br>
well before the onset of autumn migration, and trans-Saharan<br/><br>
migrants visited post-migratory stopover areas in tropical Africa. By<br/><br>
these movements, the harriers presumably exploit short-term regional<br/><br>
variation in food abundance. Autumn and spring migration occurred in<br/><br>
a relatively narrow corridor, without distinct differences between sexes<br/><br>
in timing, speed, distance, and duration of migration, except that<br/><br>
females tended to migrate faster in spring than did males. Juveniles<br/><br>
migrated shorter distances than adults, and migration speeds were<br/><br>
lower. Spring migration was similar to autumn migration in terms of<br/><br>
speed and duration. Juveniles did not cross the Sahara Desert and three<br/><br>
birds, one female and two juveniles, wintered in Europe, which is in<br/><br>
accordance with a recent increase in the number of (juvenile) Marsh<br/><br>
Harriers wintering in northwestern Europe. All birds that crossed the<br/><br>
Sahara wintered in tropical West Africa. Harriers showed site fidelity to<br/><br>
breeding, wintering and stopover areas. The overall migration speed of<br/><br>
Marsh Harriers was similar to that of Ospreys Pandion haliaetus and<br/><br>
Honey Buzzards Pernis apivorus, two other trans-Saharan migrants.<br/><br>
Ospreys use fly-and-forage migration to promote resulting speed,<br/><br>
whereas Honey Buzzards are particularly apt to exploit thermal soaring.<br/><br>
How Marsh Harriers balance foraging versus travelling to accomplish<br/><br>
their rapid migration speeds remains to be resolved.},
  author       = {Strandberg, Roine and Klaassen, Raymond and Hake, Mikael and Olofsson, Patrik and Thorup, Kasper and Alerstam, Thomas},
  issn         = {0373-2266},
  keyword      = {Marsh Harrier,post-migratory movements,pre-migratory movements,satellite tracking,migration},
  language     = {eng},
  number       = {2},
  pages        = {159--171},
  publisher    = {Nederlandse Ornithologische Unie},
  series       = {Ardea},
  title        = {Complex timing of Marsh Harrier Circus aeruginosus migration due to pre- and post-migratory movements},
  volume       = {96},
  year         = {2008},
}