A lot of skins, some HQ, some Shiny Bear Teeth/ ok plat a few Mesa Hardstones and Fossils but very very little in the way of armor.. Seems to be less than 1%
Started fighting them at barely 28 as a untwinked shaman with a tank merc. Spells started landing more or less reliably at 30. Saw the first Yellow con one at halfway through 32 so they start at 34.
'a mesa bear' cannot be lvls 40-45. Husband and I were killing them at lvl 38 and they were blue to us. I estimate their lvls anywhere from 32-37 - unless there are other places to hunt bears - we were by the bear caves just west of Pioneer Vulu.