SEATRACK-data used to study the relationship between wind patterns and migrating movements.
For the black-legged kittiwake, which is a relatively small and lightweight gull, wind support may be very useful during migration to and from the wintering areas. Photo © Morten Ekker
Several seabirds cover large distances annually between their breeding and wintering grounds. A number of factors could influence the shape of the chosen route, such as food availability, habitat, predators and weather. In a multi-national study, researchers examined the importance of wind patterns on the migration route of two seabird species wintering in the North Atlantic.
Migration is a common trait among many animals, allowing the exploitation of spatiotemporally variable resources. It often implies high energetic costs to cover large distances. For flying or swimming animals, adequate use of winds and currents can help reduce the associated energetic costs. Migratory seabirds are good models because they move through habitats characterized by strong winds during their very long migrations.
In the study presented here, researchers tested the hypothesis that seabirds migrate through areas with favourable winds. To that end, they used the SEATRACK dataset, a multi-colony geolocator tracking dataset, for two North Atlantic seabirds with contrasting flight capabilities, the black-legged kittiwake Rissa tridactyla and the Atlantic puffin Fratercula arctica, and wind data from climate models.
The main migratory routes of both species were similar and followed seasonally prevailing winds. The general migratory movement had a loop-shape at the scale of the North Atlantic, with an autumn route (southward) along the eastern coast of Greenland, and a spring route (northward) closer to the British Isles. While migrating, both species experienced higher wind support in spring than in autumn. Kittiwakes migrated farther, but also benefited from higher wind support than puffins on average. The variation in wind conditions encountered while migrating was linked to the geographical location of the colonies. Generally, northernmost colonies had a better wind support in autumn while the southernmost colonies had a better wind support in spring, with some exceptions.
What if the winds turn?
The study helps us understand how the physical environment shapes animal migration, which is crucial to further predict how migrants will be impacted by ongoing environmental changes. Wind patterns are expected to change as a result of the ongoing climate changes, but how seabirds will adjust their behaviour and movements to such shifts remains hard to tell. The authors behind the article propose that further studies focus on investigating the seabirds’ responses to various wind conditions for us to better understand their ways and chances of adapting.
Read the full article: Multi-colony tracking of two pelagic seabirds with contrasting flight capability illustrates how windscapes shape migratory movements at an ocean-basin scale
Contact: Arnaud Tarroux