I've asked this before years ago, just wondering if any of yous notice a difference in castor? Round here I've noticed that I will get some specimens with purple-ish sacks, and some have lighter beige sacks...would this be age, or brand? Just curious.

Good question. It may have something to do with diet. Around here the beaver that primarily live on cottonwood almost always have light colored castors, whereas, the coastal pond beaver that live on Lilly rhizomes tend to have darker colored ones. Almost always.

Yea I do all the time... I ground about several pounds of castor this morning. Most was mine from here in Eastern,Ky... Some was from Ohio and some was from Oregon... The Ohio castor was lighter than mine, the Oregon castor was a whole different thing all together. Looked different and smell way different.Not as harsh, more sweet.. My castor is generally very dark and loud, almost bitter smelling...

I think it is definitely a diet thing.
For example a wild hogs fat can be yellowish to pinkish depending on what they're eating.

This is the color when they have been eating, beech, yellow birch, maple, and black cherry.

Cottonwood and willow.

Here's the difference in what I catch.

Yukon , just like the difference in coastal and big river beaver in my areas. Diet.

This is my usual color everywhere I trap. Mix of hardwood,willow,cottonwood

Thanks for weighing in guys.

pm'd you yukon