Does the seabird sanctuary accept healthy birds that people want to donate to them

You should call before you go there.

You should never take a healthy bird from the wild. If the bird is domesticated then they can help you find it a new home.

No

As long as they're wild sea birds, they also accomodate owls and hawks. But no domestic birds.

I have only ever seen native Seabirds like Pelicans, Gulls, Cormorants. No unwanted Parakeets etc.

Not sure.