MAGNETIC ORIENTATION OF SNOW BUNTINGS (PLECTROPHENAX-NIVALIS), A SPECIES BREEDING IN THE HIGH ARCTIC - PASSAGE MIGRATION THROUGH TEMPERATE-ZONE AREAS

Citation
R. Sandberg et J. Pettersson, MAGNETIC ORIENTATION OF SNOW BUNTINGS (PLECTROPHENAX-NIVALIS), A SPECIES BREEDING IN THE HIGH ARCTIC - PASSAGE MIGRATION THROUGH TEMPERATE-ZONE AREAS, Journal of Experimental Biology, 199(9), 1996, pp. 1899-1905
Citations number
45
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biology
ISSN journal
0022-0949
Volume
199
Issue
9
Year of publication
1996
Pages
1899 - 1905
Database
ISI
SICI code
0022-0949(1996)199:9<1899:MOOSB(>2.0.ZU;2-F
Abstract
Orientation tests were conducted with snow buntings (Plectrophenax niv alis) exposed to artificially manipulated magnetic fields, during both spring and autumn migration. Experiments were run under clear sunset skies and under simulated complete overcast. The birds closely followe d experimental shifts of the magnetic fields during both seasons regar dless of whether they had access to celestial cues. Clear-sky tests in vertical magnetic fields resulted in a significant bimodal orientatio n, the directionality of which was almost identical during spring and autumn. When the snow buntings were deprived of celestial directional information and tested in vertical magnetic fields, they failed to sho w any statistically significant mean directions in either spring or au tumn. The results demonstrate that snow buntings possess a magnetic co mpass and suggest that magnetic cues are of primary importance for the ir migratory orientation while on passage through temperate-zone areas . However, the axial orientation in vertical magnetic fields under cle ar skies may indicate an involvement of celestial cues as an auxiliary source of directional information.