What lives here?
I have noticed well worn small trails along almost all the bodies of water around where I live, running parallel to the water along the bank. They frequently go through quite dense brush with just a small opening at the bottom so I know they are not deer trails. Along one of these trails I found an intersection with a short trail leading down to the water, and a short trail leading into a small burrow and latrine. The latrine appeared to have old and fresh feces - and the old feces looked like it full of small shell bits. I've included photos of the burrow, latrine, and decomposed feces with shell bits. Do you know what creature lives in this burrow? A hint may be that along a similar trail I saw small, hand shaped prints in the snow but I am not sure that they are from the same creature.
Kalamazoo County Michigan
This is a fun question-thanks for sending it in! I feel like I have to figure out the "mystery" animal. I think the biggest clue you have given me is the shell fragments in the scat. This sounds like a river otter. In fact, I just observed two river otters hunting for food along the shore line of a small lake just yesterday. They are particularly active right now because the weather is warming up a bit and waterways are opening up more.
River otters eat fish and crayfish, clams and sometimes snails too, so the fragments in the scat could be crayfish exoskeleton or shell fragments. When they catch a crayfish, they will swallow it partway and then rub their necks on the ground to help with the swallowing and breakdown of the crayfish. It is really fun to see. But the exoskeleton of the crayfish doesn't digest well and will show up in the scat.
If you search "images" on-line of river otter scat, compare those pictures to the ones you have.
Minks and muskrats have different diets--minks tend to eat small mammals, and muskrats are more vegetarian.
River otters are quite large and could leave those wider pathways and scat. The burrow looks like a river otter burrow, too.
If you hide somewhere along their pathway, you may get a chance to observe them as they can be active during daytime hours (mostly morning or evening) in cooler weather. Come warmer weather, they become more nocturnal.