Related Experiment Video
Updated: Feb 24, 2026
08:28
Using Pharmacological Manipulation and High-precision Radio Telemetry to Study the Spatial Cognition in Free-ranging Animals
Published on: November 6, 2016
7.1K
Migratory Eurasian Reed Warblers Can Use Magnetic Declination to Solve the Longitude Problem
Nikita Chernetsov1, Alexander Pakhomov2, Dmitry Kobylkov3
1Biological 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.
Current Biology : CB
|August 22, 2017
Summary
Migratory birds solve the longitude problem using magnetic declination, not time. Experienced Eurasian reed warblers corrected their course when magnetic declination shifted, suggesting a novel navigation method.
Area of Science:
- Ornithology
- Animal Navigation
- Geophysics
Background:
- The longitude problem is crucial for navigation but challenging for birds lacking a time-sense.
- Migratory songbirds can correct east-west displacements, yet their method remains unknown.
- Existing research highlights birds' ability to use latitudinal cues.
Purpose of the Study:
- To investigate how experienced migratory birds solve the longitude problem.
- To test the hypothesis that Eurasian reed warblers use magnetic declination for east-west positioning.
- To differentiate navigation strategies between experienced and juvenile birds.
Main Methods:
- Field experiments with adult and juvenile Eurasian reed warblers during autumn migration.
- Manipulating magnetic declination (8.5° shift) while keeping other cues constant.
- Recording and analyzing heading changes in response to altered magnetic declination.
Main Results:
- Experienced adult birds altered their heading by 151° (WSW to ESE) when magnetic declination changed, indicating compensation.
- Juvenile birds, lacking established navigational maps, became disoriented after the magnetic declination shift.
- The response of adult birds suggests magnetic declination is integrated into their navigational map.
Conclusions:
- Experienced migratory birds, like Eurasian reed warblers, can use magnetic declination to solve the longitude problem under clear skies.
- Magnetic declination, combined with latitudinal cues, may form a bi-coordinate navigation system for experienced migrants.
- This finding offers a new perspective on avian navigation and the mystery of the longitude problem in birds.
Related Concept Videos
01:19Magnetic Declination
516
Magnetic declination is the angle between true north, which aligns with the Earth's rotational axis, and magnetic north, which follows the direction of the Earth's magnetic field. This discrepancy exists because the magnetic poles do not coincide with the geographic poles. The value of magnetic declination depends on the observer's location on Earth and is subject to changes over time due to the dynamic nature of the Earth's magnetic field.The declination is called eastern when magnetic north...
516
01:23Compass
9.7K
The compass is a fundamental instrument that operates by aligning its magnetic needle with Earth's magnetic field. This alignment facilitates navigation and orientation, offering a means to determine direction relative to magnetic north. However, the magnetic needle points to magnetic north, which differs slightly from true geographic north due to magnetic declination, which is the angular deviation between these two points. Declination varies based on geographic location and shifts over time...
9.7K
01:28Meridians
980
In surveying, meridians are vital reference lines to measure directions and establish accurate land orientations. Meridians run from the north to the south poles, providing a stable framework for angular measurements and mapping. Meridians are fundamental in survey design, with the primary types being astronomic, magnetic, and assumed meridians. Each type offers distinct benefits and limitations, selected based on the project's scale and precision needs.The astronomic meridian is aligned with...
980
00:53Migration
9.0K
Migration is long-range, seasonal movement from one region or habitat to another. This common strategy, carried out by many different organisms around the world, is an adaptive response that typically corresponds to changes in an organism’s environment, like resource availability or climate. Migrations can involve huge groups of thousands of animals as well as single individuals traveling alone and can range from thousands of kilometers to just a few hundred meters.
9.0K
01:12Adjusting a Traverse
397
In the site survey of a four-sided traverse, internal angles are essential to ensure geometric accuracy. The survey revealed that the sum of the measured internal angles was 359 degrees and 48 minutes, which is 12 minutes less than the expected 360 degrees. This discrepancy signals an error likely arising from measurement inaccuracies during the fieldwork.To rectify this error, the adjustment process involved distributing the 12-minute shortfall equally across the four internal angles. By...
397
01:27Magnetic Fields
7.5K
A moving charge or a current creates a magnetic field in the surrounding space, in addition to its electric field. The magnetic field exerts a force on any other moving charge or current that is present in the field. Like an electric field, the magnetic field is also a vector field. At any position, the direction of the magnetic field is defined as the direction in which the north pole of a compass needle points.
A magnetic field is defined by the force that a charged particle experiences...
A magnetic field is defined by the force that a charged particle experiences...
7.5K