Why do scientists study animals migration?

What do the following scientists study and under which category-- life, Earth, or physical?

• What do the following scientists study and under which category-- life, Earth, or physical? Example: Zoologist-- life scientist that studies animals and observes them in laboraties or in their natural habitat. Scientists: astronomer ethnobotanist paleontologist meteorologist ichthyologist ornithologist entomologist chemist anthropologist herpetologist thank you, and please, no obnoxious answers!!

• Answer:

  astronomer -earth scientist that studies stars and outer space ethnobotanist -physical scientist that deals with relationships between people and plants paleontologist - physical scientist that studies fossils meteorologist - Earth scientist that studies weather and Earth's atmosphere ichthyologist -life scientist that studies fish ornithologist - life scientist that studies birds entomologist -life scientist that studies insects chemist - physical scientist that studies chemistry/ chemicals anthropologist -life scientist that works with people herpetologist - life scientist that studies reptiles and their habitats