Dr. Courtney said:
I'd focus on the best colleges for science in your state - at a minimum a college with both strong biology and strong chemistry programs. ACS accreditation is usually the mark of a strong chemistry program, especially if most of the chemistry majors earn the ACS accredited degree.
Take all the science and math you can in high school. Be sure to get AP or honors chemistry. You will need that background for most of your biology courses in college, and most biology majors need to take a year of general chemistry and then a year of organic chemistry in college. The best biologists are very good at chemistry and math too.
Do not sell yourself short with less than four years of high school math.
The best way to actually study zoology/ethology in high school is to do a science project for competition at an ISEF affiliated science fair.