At the end of summer numerous bird species begin seasonal migrations, travelling long distances from breeding areas to milder wintering grounds where food and conditions are more favourable.
Why they migrate
Migration is a survival strategy that lets birds exploit abundant resources during the breeding season and then move to regions with more reliable food and milder climates for the non‑breeding months. As summer ends and daylight shortens, physiological changes and environmental cues trigger departures that reduce the risk of food shortages and cold weather stress.
Timing and cues
Timing of migration is driven by changes in day length, food availability and weather. Many species begin preparatory behaviours late in summer: feeding intensively to store fat, gathering into flocks and selecting departure nights when winds are favourable. These cues synchronise movements so that populations arrive at wintering areas when resources are optimal.
Well-known migrants
Familiar long‑distance migrants include storks, swallows and geese, each using characteristic routes and flight styles. Some species travel in tight formations to save energy, others follow coastlines, river valleys or mountain ranges that provide navigational landmarks and stopover sites for rest and refuelling.
Ecological importance
Migration links distant ecosystems: migratory birds move nutrients, pollinate plants and control insects across regions, and their seasonal presence supports food webs in both breeding and wintering areas. Conserving stopover habitats and safe migratory corridors is vital to maintain these ecological connections.
Takeaway
End‑of‑summer migration is a crucial, large‑scale life‑history strategy for many bird species, enabling them to survive seasonal change by travelling to regions with more favourable climates and food supplies, and relying on a network of habitats along established routes to complete their journeys.