Did migratory birds' ancestors live in the places of migration?

Question

I was studying birds' migration as a type of instinctive behaviour. But my textbook points out that other than for warm climate and easy food, migratory bird migrate to places where their ancestors lived. Is it a real point? Or the writers just made it up.

Answer 1

Hi there,

This question has been around for a while, but I thought I would take a crack at it.

It appears that you are asking whether birds migrate because instinct "tells" them to migrate, or whether they migrate because they "know" that they will have access to more/better food and climate conditions if they migrate.

The answer to this actually has more to do with evolution that it does with ecology. That's because a bird's desire to migrate really is just an instinct: they don't know why they do it, they just do.

The instinct to migrate is determined by evolutionary history, in which birds that migrated survived better than ones that did not, leading to the evolution of birds with stronger migratory instincts. This is called natural selection, and it's the key concept of evolutionary theory.

Although people often see animal behaviors and think that the animals are doing these things because of some "knowledge," the reality is that the behaviors are almost always determined by evolution. For example, the fact that a raccoon washes its food before eating it does not mean that that raccoon "knows" that washed food is more healthy. The raccoon does this behavior because in past generations, raccoons that washed their food survived better than the others, thus leading to a species that has this habit.

I hope that this answer helps you, or someone with the same question.

Dylan