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Updated: Jun 23, 2026
10:07
Thermal Imaging to Study Stress Non-invasively in Unrestrained Birds
Published on: November 6, 2015
Stress hormone dynamics: an adaptation to migration?
Anna L K Nilsson1, Maria I Sandell
1Department of Animal Ecology, Lund University, Lund, Sweden. anna.nilsson@bio.uio.no
Biology Letters
|May 12, 2009
Summary
Migrating blue tits did not show repressed stress responses compared to residents, challenging the migration-modulation hypothesis. Retaining stress response may benefit short-distance migrants.
Area of Science:
- Avian physiology
- Ecology and behavior
- Stress endocrinology
Background:
- Corticosterone (CORT) is a key hormone in avian stress response.
- Environmental stressors can negatively impact birds, especially during migration.
- The migration-modulation hypothesis suggests migrants suppress stress responses.
Purpose of the Study:
- To test the migration-modulation hypothesis in a partially migratory bird population.
- To compare stress responses between migratory and resident blue tits.
- To investigate the role of CORT in migratory birds.
Main Methods:
- Studied a population of partially migratory blue tits (Cyanistes caeruleus) in southern Sweden.
- Measured corticosterone (CORT) levels at capture.
- Assessed and compared stress responses between migratory and resident individuals.
Main Results:
- Migrant blue tits exhibited higher CORT levels upon capture than residents.
- No significant difference was found in the stress response between migrants and residents.
- This finding contradicts the migration-modulation hypothesis.
Conclusions:
- The migration-modulation hypothesis was not supported in this population of short-distance migrants.
- Migrants and residents displayed similar stress response patterns.
- Maintaining a stress response may be advantageous for short-distance migrants, outweighing potential harm.
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