Beavers smell different to me when caught during warm weather. Sort of a more sour smell. Do you guys think if you had access to summer castor it’d be worth leaving together alone and work good duringbtrapping season? It seems it’d be more of a curiosity appeal if it’s just not in my head that it does smell different. May be no real difference or maybe it’s just a hot beaver smell ?

Not sure but I've smelled the smell you are referring to.....tangy smell.

I find the best castors for smell and fullness comes from spring beaver taken under the ice in mid to late march.
A few of these are what I take for making my beaver lure.

Might be my imagination on smelling different Mike.

I will say that when I trapped beavers in S. Indiana and Kentucky I thought the castor smelled sweeter than the N. Illinois castor.

I definitely notice summer/early fall castor is less potent it seems.

Especially in younger individuals.

I just never had seen this discussed. If it is milder even it’d be different than the trapping season smell of it and might be a bottle of hold back for shy ones? Maybe not even worth thinking about. I just thought if I were a nuisance trapper now I’d be tempted to hold a few castors back separate and try them.

Possibly because of a change in diet? Our beavers down here tend to eat aquatic vegetation during the summer months more so than wood.

I’d say that’s exactly what it is. Hadn’t thought that deep. Eastern Ky beaver definitely have a different smell and color than western Ky ones that eat a lot of grasses year round. The west Ky castor is more yellow when ground, like baby poop sometimes, and I tend to like it more here than my local blend. I prefer my local castor for cats or any land trapping though.

I don't know about summer castor, but I know some of the southern or eastern castor doesn't even smell like castor to me, it smells so much different than the castor we have here. And some of the luremakers from there, I'm pretty sure Paul is one of them, won't buy and use castor from here because it makes their lures so different than what they formulated with southern castor.