New York University Animal Migration Discussion

I’m working on a Zoology question and need guidance to help me study.

The Channel-billed cuckoo is a large migratory bird species that is also a brood parasite. It breeds in Australia. After the breeding season it migrates north and spends the southern winter in New Guinea and Indonesia. Because adults do not raise their own young they typically leave the breeding grounds and start migrating long before their young do.

Imagine that you are a researcher studying two populations of these birds. Both of these populations breed close together within the same general geographic area in Australia, but you have noticed that over several decades, the migratory direction of one of the two populations (population A) has shifted and they are now following a direction that leads them further east (a northeastern route) and they end up on a different island where they spend the winter. The migration route of the second population (population B) has not changed, they are still following a northwestern route.

A) Is the shift in migratory direction of population A likely to represent an evolutionary change in this population? Why or why not?

B) You decide to test whether this shift represents an evolutionary change by mating a female from population A with a male from population B in your lab in Australia. You then plan to track the migratory direction of the offspring. If the shift in migratory direction in population A is indeed an evolutionary change, what direction would you expect the offspring to fly in during their migration?