What sort of educational background is needed?

To become a "entry-level" biologist you would need to go to collage and get your bachelors degree.
Depending on your future area of specialization within ecology, you may also want to have an academic background in such diverse subjects as economics, geology, mathematical modeling, oceanography, sociology. Ecologists in research and consulting need a masters degree, ecologists that want to be research and university teaching you will need a PhD.