Just wondering, cause I have 2 beaver to go by, and in my limited experience it seems the males have a bigger sack, and the females have a more "colorful" (and smaller)sack. Any thoughts are appreciated!

I noticed the same thing this year. I think that males have larger castors in general. I didn’t notice a color difference though. Maybe someone with more experience will chime in.

As a general rule, I've found that the females will have smaller castors than the males. There always exceptions though.

" the males have a bigger sack"
Yessir they do

Thanks Paul, have you noticed a difference in color? The male I harvested from was clearly more of a yellow color, and the female was a purple, or plum maybe. Just food for thought, I'm extremely new to this!

No, I haven't noticed a difference in color between male and female. I have noticed a difference in color and outer membrane thinness between locations. Some locations will produce castors with a nice light colored castor with a good durable membrane. Some locations have a dark castor with a thin membrane that is subject to tearing when removing. I'm not sure what causes the difference.

Thank you, been wondering how tough castor actually is when I harvest! It seems that when I try to extract I always get pretty rough. Haven't torn any yet, but wonder how much they can take?

Males definitely seem to have more castor. I also noticed the beaver I caught in December seemed to have fuller castor sacs then these spring beaver. Here's a male and female castor from yesterday. Anyone else noticed some beaver sac oil is yellowish/white and thin while some is thick with a brown tint?

Well, the male will be the one with the testicles inside, for whatever that's worth .

The biggest beaver I've caught and also saw another local trapper catch, were both females.

That's a biggun!

Your sac oil color difference is male vs female. Yellow/female. Brown grey/male

...well, caught the male that was with the female with the purple colored castor, and he had the same color as her. A little bigger, maybe, but I would ascertain that color has something to do with nutrients in what they're eating. Again, I'm NO expert, just food for thought!

You can make them bigger by leaving them out in the sun for a while.

Exactly. Plus the consistency of female oil is grainy like vaseline where the male's oil is oily and brown.

‘Peeler you still making those fine beaver lures?

Down here, the female's oil is very light in color and liquid. The male's oil is brown, and many times it's thick like paste.