Study
Long-distance migration: evolution and determinants
Alerstam, Thomas; Hedenström, Anders; Åkesson, Susanne
Oikos, 2003
Synthesises the ecological and evolutionary factors that determine whether, when and how far animals migrate, including energetics, flight mechanics, seasonality of resources, and the constraints of crossing barriers.
- Studied in
- Aves, Animalia
- Sample size
- synthesis of migration ecology across taxa
Long-distance migration is best understood as a solution to seasonal resource variation whose limits are set by energetics and by the geography of barriers, and which evolves and disappears repeatedly rather than being a fixed property of a lineage.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
Migration distance and route are the outcome of optimisation under constraint, not of a species-level instinct to travel.
How NatureHQ reads it
Used for the framing rather than for a number: migration is a strategy an animal follows when the arithmetic of staying is worse than the arithmetic of leaving, and populations of the same species can and do come to different answers.
- A review: the individual results it draws on carry their own scopes and are cited separately where NatureHQ uses them.
- Bird-weighted, as the literature is.
What this study is used for on NatureHQ
One study can inform several subjects. Here is everywhere this one is cited.
Migration
Migration is not defined by how far an animal goes. It is defined by a change in behaviour: movement that keeps going in one direction while the responses that would normally stop it are switched off.
Migration
There is no single migratory pattern. Some populations go every year and some only in bad years; in many species some individuals leave and their neighbours stay.
Migration
Day length decides roughly when to go, because it is the one signal that never drifts. Weather decides the night: migrants wait, then leave in pulses when the wind turns favourable.
Published by: Wiley journalsPublished in a Wiley journal.
doi.org/10.1034/j.1600-0706.2003.12559.x
Checked against Crossref on 2026-09-28, and they agree on the title, the authors and the year.
NatureHQ summarises research in its own words and does not reproduce published text. Reviewed 2026-09-03.