Most migrations begin with the birds starting off in a broad front. Often, this front narrows into one or more preferred routes termed flyways. These routes typically follow mountain ranges or coastlines, sometimes rivers, and may take advantage of updrafts and other wind patterns or avoid geographical barriers such as large stretches of open water. The specific routes may be genetically programmed or learned to varying degrees. The routes taken on forward and return migration are often different. A common pattern in North America is clockwise migration, where birds flying North tend to be further West, and flying South tend to shift Eastwards. COUNT 5
QSN1 How do most migrations begin? ANS1 the birds starting off in a broad front QSN2 What to the migrating birds usually follow? ANS2 mountain ranges or coastlines QSN3 What obsticals will migrating birds avoid? ANS3 large stretches of open water QSN4 What is a common pattern in North America migration? ANS4 clockwise QSN5 What are the preferred routes for migration called? ANS5 flyways