Many types of birds expend large amounts of energy to fly long distances in the spring. How can a trip like this be worthwhile to
the birds?
O
Select one:
O a Birds that migrate find an abundant supply of food and safer nesting areas
b. Bird migration is an instinct that birds retain from their ancient ancestors, it has little value for bird populations in today's
world
c. Birds must change food sources during the year to be able to balance their diets
d Birds expend little energy when they fly and they stop often to take breaks
O