Thought I would give my 2 cents here. Sound to be like both sides of this were out of line and emotional. I don't think I would recomend going to the priciple or try to get the guy fired. Instead, I'd appologise for the way YOU handled your disagreement and would like to discuss it out of class. There, I would give him information on the mule deer population decrease, and acknowledge you were incorrect about the "increase in population" - However they are FAR from being endangered.

Do not raise your voice, do not taunt, regardless of his reactions.
Here are some links
http://www.seeleylake.com/pfnews/200...rmuledeer.html
http://www.co.missoula.mt.us/measures/muledeer.htm
http://www.muledeer.org/
http://cgi-bin.nando.net/newsroom/sp...8outdoors.html
http://gf.state.wy.us/HTML/hunting/harvest00deer.htm
http://www.planetvmth.com/DeerHunter4/mule.htm
These are just some places to get info - check with you local department of fish and wildlife as well.