Arctic tern wind strategies
Comparing how two Arctic tern populations use Atlantic wind patterns during migration.
Context
Wind has a major effect on long-distance bird migration. For Arctic terns, wind can save energy, slow movement, or push birds away from their route.
This project asked whether different tern populations respond to the same wind system in the same way.
Approach
I combined tracking data from Dutch and Svalbard Arctic terns with ERA5 wind data and climate-model wind fields.
The analysis compared wind support, crosswind, route shape, and drift behaviour across the two populations.
Key components
- Tracking data: routes from tagged Arctic terns.
- Wind support: how much the wind helps forward movement.
- Crosswind: side winds that can push birds off course.
- Drift ratio: a measure of whether birds drift with the wind or compensate for it.
Results
The Svalbard birds made better use of supportive Atlantic wind patterns and often allowed themselves to drift over large regions.
The Dutch birds followed straighter routes and tended to compensate more for crosswinds, which suggests a different migration strategy.
Why it matters
This shows that even within one species, populations may respond differently to the same changing wind system.
That matters when thinking about climate change, because future wind shifts may not affect all populations in the same way.
Tools
Tracking data, ERA5, climate-model wind data, Python, and spatial analysis.