Smithsonian ornithologist John Rappole reconsidered why birds migrate - Mongabay

Theory Briefing

• John Rappole's dispersal theory reframes migration as tropical birds pushing outward into seasonal northern habitats, not cold-weather refugees retreating south.
• The theory directly challenges a long-standing view that migration evolved as a survival response to harsh northern winters.
• If Rappole is right, the tropics — not the north — are the ancestral home of most migratory bird species.
• The distinction matters for conservation: protecting tropical wintering grounds may be as critical as preserving northern breeding habitat.