what animals cant you put on a tether line rather than fence in?

if I have a long narrow area to be grazed, a tether is much easier than fencing. which animals wouldn't work for this setup? cows seem to strong. snakes to hard to harness, winged creatures?

The problem with tethering is you need to be near unless you run a "clothesline" with a drop line from that so they don't get tangled in it. Otherwise, you risk the animal choking itself.

It is common here to tether goats, but only when there are people present. Same with horses. I have never seen it done with cows, but that doesn't mean no one has.

I often tether my ram and just make sure it's secured low so he wont choke/hang himself. I tried tethering goats but they always hogtied themselves with 15 minutes.

It really depends on the individual animal and how well you train them.

Portable electric paddock systems are fairly cheap and easy to move. They can be worth it just to avoid the headaches of tethers and uncooperative animals.

My tip-of-the-day:

Many of the portable fence systems use fiberglass posts, which can be difficult to install in hard, rocky soils.
The posts can be easily damaged in such conditions.
If you carry a cordless drill with appropriate sized bit, you can simplify the time/effort of moving the posts.

Tethering makes your animal more vulnerable to predators.

I had some goats when I was a kid. They got so tangled up that I had to cut ropes. We had an old horse that was careful about tangling so she got to eat lush grass from the roadside ditch when other pasture was overgrazed. The younger, high strung horse was a danger to himself and others when tied so he had to eat dry grass and goldenrod. Mona, the old horse was also well behaved when taken out for rides. I sometimes took her to wild apple trees where she browsed both leaves and apples.

A tethered animal is easy prey to predators or neighborhood dogs. Just a few weeks ago, a goat in the neighborhood was killed by a couple of loose dogs. I would not tether an animal unless it was inside a fenced area already and you just wanted to control its location.

With the problem of hog tying, a retractable lead like found on many leashes would fix that?

I'd like to see a clothesline, somehow attached to harness the power to aid in drying in non windy areas.

which animals wouldn't work for this setup? cows seem to strong. snakes to hard to harness, winged creatures?

I tether my goats and I tether my cow. I tried a sheep briefly, but they're dumb and panicky and the collar gets lost in the wool. I have to untangle probably twice a day on average but because they wrap around brush, not themselves. The goats hogtied themselves a couple times early on but now they seem to have it figured out. The cow never has, but she's a short-legged Dexter, it might be physically impossible to do to her. It probably wouldn't work so well on a wild range cow. Their tethers have swivel clips at both ends which helps keep the lines straight, I wouldn't put clothes and goats on the same line. It's a high-maintenance way to go, the best way I've found to keep the outside of my fences clear, but it's only a good option if there's no other. I had one horse ever that I would trust to tie out, they have such long, fragile legs and necks. I wouldn't tether birds. Or bunnies...

the old world jersey is traditionally kept on a tether on the isle of jersey

traditionally family cows were tethered
I would not leave my cow unattended ever, I tether her ONLY when we are tending that area with her