You can't "call a Cow", they way you would call a bull. Just doesn't work that way. Saying that, a cow that has lost here calf can usually be attracted by the sound of a calf in distress but only if she lost the calf within the last day, maybe two. She will stay in the general area, usually within a quarter mile.
If someone kills a calf moose and removes it from the area, Momma will come to "investigate" a distress call.
A little caution here too, Momma moose may not be in the best of mood either, she's comming to assist her young who is calling for help. She can get pretty bitchy and those hooves can be deadly.
Those calls are actual moose. Practice them. The better you get,the better the chance of success. Personaly, I prefer a birch bark horn, 18-22 inches long, it reverberates the sounds better.
When calling coyotes, more often than not they will circle on a target they are
coming into and approach from the downwind side. Presumably they do this in
order to align what they smell, with what they are hearing.
This means that you should always have your downwind side camouflaged and have
an open shooting lane. If the area is heavily covered the coyote could come in
take a look and be gone, with you none the wiser.