Had a doe get stuck in a woven wire fence years ago way back in a hay field during the winter. It died in that fence so yes nature is cruel some times. Shame no one noticed it and got it loose.
I disagree on the jars being the worst. While they are bad what slob fisher men women leave laying on the ground and in the water is far worse way I see it. Slobs should dispose of monofilament properly where no animal will get tangled in it. Best to melt it into a lump then put in the trash.
Rings that hold pop and beer is also bad for the wild life.

Al