Abrasion generally occurs four ways. Glaciation slowly grinds rocks picked up by ice against rock surfaces. Solid objects transported in river channels make abrasive surface contact with the bed and walls. Objects transported in waves breaking on coastlines cause abrasion. I HOPE THIS HELPED:)
Birds migrating in the winter would be a behavioral adaptation. The rest of the adaptations would be structural or physiological because they are controlled by mutations in the DNA. <span />
