I have covered cloth bird forms with plaster, but they've been small. This large one is an experiment because I'm not sure if it will crack or flake off the fabric form.
Plaster is fun to work with. It can be painted and with watery paint-it has a lovely look. Scratch marks on it, and wipe a wash of brown paint over the marks. Or wax the surface, then mark it and wipe a brown glaze over that.
I was concerned about wet plaster burning my skin-but it didn't. I did use a heavy plastic glove, but I got some on my other hand-no burn. Do not ever wash up inside-your drains will clog.
I've read that using dry wall spackle like plaster works and has a much slower drying time.
To make this experiment maybe more successful, I should have used plaster gauze over the form, then applied the plaster-but maybe this will work without it shedding. I have to chip away the plaster from the bird's eyes, and off his beak.