@NeoDymium Nice summary. There are also many math majors in my field, resource management. These people typically got an undergrad degree in math and then went on to graduate school in Biology, Zoology, Oceanography or Fisheries. Fisheries is very quantitative so full of people with b.s and m.s. degrees in math. PhD in (applied) math is much less common though some of the top ‘thinkers’ in these fields come from that background. Training in modeling and statistics (esp. Bayesian) and informatics is especially important in these fields. Ability to communicate and work well in interdiscipliniary teams is really important if you go in this direction with a math background. Also you’ll have a hard getting a job (undergrad or post-undergrad internship) without classes in the whatever field you are aiming for (Wildlife, biology, oceanography, fisheries, earth sciences…). Then there is the whole academic theoretical biology side—job prospects there are limited to academia however.
Though I describe myself as a applied mathematician (research in time-series analysis), my own path went through Mechanical Engineering + Biology --> Zoology PhD (theoretical biology). The Mech Eng training was very useful because it was all about taking real world problems and figuring out reasonable solutions, which in Mech Eng involved math & models.
H’s path, also an applied mathematician, was Math B.S. --> Stats M.S. --> Operations Research PhD which led to a career in computer science, not writing code but working on algorithms related to image processing and compression.