I was removing the castor glands from a spring beaver this afternoon and found what looks to be a "plug" between the glands and the anal tract. It's soft, much like those foam earplugs. Never seen or heard of such a thing. What say you beaver experts?

Only found on male beaver.

Yepper, but I don't know what it is.

maybe beaver tampex?

I see it on male beaver pretty often, don't know what it is.

prostate?

I often wondered the same thing, Danny.

Ya, always see these collecting in the castor gland tract. Seems like perhaps a malfunctioning castor gland causes it to build up, but that is a complete guess. I yank it out and harvest the castor in the regular way. Doesn't affect much.

I hope somebody knows TTT

It is called a copulation plug or spermatic plug.
It is an adaptation by some species to allow more time for the sperm to fertilize the egg.
It is deposited by the male into the female and holds the sperm in the vaginal tract.
Also insures against multiple paternity if another male beaver is "waiting in the woodpile".

so its only in knocked up females?

Good thing humans don’t do that or Maury would be out of a job

Only see it in males when you remove the castors.Males deposit it in the female while mating.

That sounds right, Boco. But then subsequent copulations by the mate would not be of benefit for the pair?

Maybe that's why you find the odd dry female.

That's an interesting bit of information. Fascinating on how animals change and adapt to stiuations. Thanks Boco!

Thanks Boco ,I did'nt know that .

I always thought it was the baculum of a beaver.
https://www.boneroom.com/store/p2/Beaver_Baculum.html

I have seem similar plugs in muskrat. It looks like its made out of a mushroom stem material.

Yes, that's a great analogy of what it looks like!