In the tropics there is little variation in the length of day throughout the year, and it is always warm enough for a food supply, but altitudinal migration occurs in some tropical birds. There is evidence that this enables the migrants to obtain more of their preferred foods such as fruits. COUNT 4
QSN1 Where is there little variation in the length of day throughout the year? ANS1 In the tropics QSN2 Why does altitudinal migration occur in some tropical birds? ANS2 to obtain more of their preferred foods QSN3 What are tropical birds preferred foods? ANS3 fruits QSN4 Where is it always warm enough for food supply? ANS4 In the tropics