Was checking a lake on a property I'm trapping for beaver sign. Walking one of the drains as it enters the lake, there were groups of 2-3 mussel shells periodically along the bank. Water is too deep for coons and I'm guessing otters are feeding on the mussels.

No other toilets have been located but I may put some Conibears in the channels where I have pinch points. These shells are basically the only sign.

As far as beaver, I did find an old bank den an the occasional chewed stick. No good sign where they're leaving the water to feed. Maybe a solo Yankee beaver with a feed pile ?

Muskrat will also eat mussels.

What a Yankee beaver ?

The one that remains and outsmarted his adversaries

I'm guessing muskrat also.
Maybe I just haven't been paying attention, but I don't recall ever seeing where river otter have shown any sign of eating clam/mussels, either fresh or salt water. Mostly just fish and crustaceans; even where there a LOTS of clams.

That make perfect sense. No doubt how a Yankee can survive down there.

I'm in South Alabama, doubt it's a muskrat.

Most of our beaver down south don't really make feed.beds because food is readily available all year. I call them yankee beaver since they behave more like their northern cousins.

Otter have almost destroyed the mussels in the one river I trap here. Not many fish in it and they prefer the large 3"+ ones

If you aren't seeing any sign it be muskrats. Shells last along time. I have a spot on mu trapline where rats have one big feed bed made of shells about 2' across. This pond has a few shells here and there around the shore. Some are about 1'' long and some up to about 4'' long. The rats set up on the back and eat them. They are about 8'' to a foot from the edge of the water.