Getting a masters in WildLife Biology after receiving a PhD in math advice I am currently working on getting my PhD in theoretical math. My dream has always been to work with animals and help preserve our wildlife. I would like to become a wildlife biologist. I checked some graduate programs in wildlife biology and they do not require for me to have a bachelors in the related field (although of coarse, that helps). I plan on taking some undergraduate (and eventually graduate courses) while in graduate school in order to get the background necessary to be a good candidate for a graduate program in wildlife biology.

I would like to be involved in the graduate program my school has right now, but as a graduate student in a different program I am not sure how to do so. Should I email someone and ask if I can attend their colloquium talks and such?

Is the approach I am taking doable, or am I unlikely to be accepted into a program without a bachelors in biology (or something more related)

Finally, I was planning on taking the undergraduate classes pass/fail. Should I take them for a grade instead?

Any advice/comments?

Thanks!
You almost certainly won't need a BS in biology and you should, if possible, take the undergraduate deficiency courses for a grade.  Now for the more general advice:

I have known many people (in my university) who have been in Ph.D. programs while taking courses in other graduate programs or even entering other graduate programs, so it won't be a problem, except you need to talk with both your committee in mathematics and a representative of the Wildlife graduate program.  From the latter, you should find out if you can enter the program now (while in the Ph.D.) and what undergraduate deficiency courses would allow you to be accepted to their Master's program.  These might only be a fraction of the courses in the undergraduate curriculum.  It is hard for someone outside the their department to tell what they think is a minimum amount of background needed to enter a program.  Some programs will also let you enter their program before all of the deficiency courses have been taken.  You can't guess at this without talking with an advisor in the Wildlife Biology program.  In fact, they might prefer that you take a graduate level broad-based course rather than some of the undergraduate courses.

At the same time, in order to have your tuition covered, you'll probably have to have your Ph.D. committee approve the courses.  If you tell them that you are interested in applications of mathematics to wildlife biology (that's true, I'm guessing) and want to take a couple of applied courses, they'll likely approve as long as it doesn't interfere with your progress in the Ph.D.

In other words, don't guess at what you need to do.  Talk with your advisor and an advisor in the Wildlife Biology program.

(In addition, you may also want to take a couple of statistics courses if you haven't had any statistics in your mathematics program.)