Something girdled my beautiful Dill

Just wondering if anyone has had this experience?

My Dill was looking awesome, taller than my new pear tree, part of a swale planting:

When all of a sudden it started wilting:

On closer inspection it looks like it was girdled by something.

I've seen a chipmonk in the area but could be a mouse or something.

I had a tough time deciding which forum to post this too! Forest Garden? Nibblers? Plants?
I can't tell if this has anything to do with the slash I put around all the plants to protect them from the chickens scratching. The slash could be good hiding for little nibblers. I may have lost a peach tree to the same nibbler but to lose dill plants that way seems really odd to me.

Anyway, I was trying to figure out what I could do with these big wilted dill plants and I wondered if there was such a thing as dill pesto ... and there is (see this could've gone in the cooking forum)

Here it is:
Dill Pesto
1 1/2 cups packed dill leaves
1/2 cup flat leaf parsley
2 tbsp pine nuts
3 tbsp olive oil
2 cloves garlic
2 tbsp Parmesan

Don't add the Parmesan if freezing. I found I needed more olive oil but that could be because the dill had already lost a good chunk of moisture. I also added some salt.

Black swallowtail butterflies have an appetite for dill, however, I haven't seen them do too much damage to a plant, just munch a few leaves.

Fortunately, an unsightly dill plant is still good as a cooking ingredient, since it is able to release its flavors in almost anything you mix it in.

Yep, the swallowtail caterpillars get mine, fennel too. Ate all of it down to the stem though, not into the stem and leaving the rest of the plant, plus they took several days to do it.

This was the exact opposite so I can rule out swallowtail caterpillars! Didn't touch anything but the stem - left the whole plant.

Already wilted dill is fine for drying, if you have a way to dry things there. Dried dill is perfectly falvorful until suddenly after several months or a year it loses its flavor and becomes totally unusable. I don't know if keeping the dried dill in the fridge or freezer would prolong its useful life.

I have that same kind of thing happening with my potatoes, and I am pretty sure chipmunks and/or voles are the culprits in my case. I also suspect that had I hilled up with dirt not mulch, I might not have had this problem, or at least not as bad...