Format

Send to

Choose Destination
Curr Biol. 2017 Sep 11;27(17):2647-2651.e2. doi: 10.1016/j.cub.2017.07.024. Epub 2017 Aug 17.

Migratory Eurasian Reed Warblers Can Use Magnetic Declination to Solve the Longitude Problem.

Author information

1
Biological Station Rybachy, Zoological Institute of the Russian Academy of Sciences, 238535 Rybachy, Kaliningrad Region, Russia; Department Vertebrate Zoology, St. Petersburg State University, 199034 St. Petersburg, Russia; Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223 St. Petersburg, Russia. Electronic address: nikita.chernetsov@gmail.com.
2
Biological Station Rybachy, Zoological Institute of the Russian Academy of Sciences, 238535 Rybachy, Kaliningrad Region, Russia; Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223 St. Petersburg, Russia.
3
Arbeitsgruppe "Neurosensorik/Animal Navigation," Institut für Biologie und Umweltwissenschaften, Universität Oldenburg, 26111 Oldenburg, Germany; Research Centre for Neurosensory Sciences, University of Oldenburg, 26111 Oldenburg, Germany.
4
Biological Station Rybachy, Zoological Institute of the Russian Academy of Sciences, 238535 Rybachy, Kaliningrad Region, Russia; School of Biological Sciences, Bangor University, Deiniol Road, Bangor LL57 2DG, UK.
5
School of Biological Sciences, Bangor University, Deiniol Road, Bangor LL57 2DG, UK.

Abstract

The longitude problem (determining east-west position) is a classical problem in human sea navigation. Prior to the use of GPS satellites, extraordinarily accurate clocks measuring the difference between local time and a fixed reference (e.g., GMT) [1] were needed to determine longitude. Birds do not appear to possess a time-difference clock sense [2]. Nevertheless, experienced night-migratory songbirds can correct for east-west displacements to unknown locations [3-9]. Consequently, migratory birds must solve the longitude problem in a different way, but how they do so has remained a scientific mystery [10]. We suggest that experienced adult Eurasian reed warblers (Acrocephalus scirpaceus) can use magnetic declination to solve the longitude problem at least under some circumstances under clear skies. Experienced migrants tested during autumn migration in Rybachy, Russia, were exposed to an 8.5° change in declination while all other cues remained unchanged. This corresponds to a virtual magnetic displacement to Scotland if and only if magnetic declination is a part of their map. The adult migrants responded by changing their heading by 151° from WSW to ESE, consistent with compensation for the virtual magnetic displacement. Juvenile migrants that had not yet established a navigational map also oriented WSW at the capture site but became randomly oriented when the magnetic declination was shifted 8.5°. In combination with latitudinal cues, which birds are known to detect and use [10-12], magnetic declination could provide the mostly east-west component for a true bi-coordinate navigation system under clear skies for experienced migratory birds in some areas of the globe.

KEYWORDS:

bird migration; magnetic compass; magnetic map; magnetic sense; star compass

Comment in

PMID:
28823677
DOI:
10.1016/j.cub.2017.07.024
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center