Hi Lisa No this is not normal. It may be too scared to go back in the lake or too tired. More than likely it sustained internal damage maybe even neurological.We would try to get it to an avian veterinarian, a waterfowl or wildlife facility quickly. Although you should not try to feed sick or injured wildlife prior to emergency transport to a vet or other hospital or facility, you may need to offer it some water if the transport is not going to happen right away ( i.e., overnight). Do not force feed it. Place a small bowl with water, bread and/or finely chopped lettuce to see if it can eat. Do not leave the swan wuth the bowl by itself. You do not want it to drown or choke from being too weak and not able to lift its head. Do not leave it outside overnight as a predator (wild or domestic) may kill it. If you have a garage or safe area place it on sheets or towels. If not, use a large box lined with a sheet or towel. You do not want the swan on any slippery surface such as newspaper, tile floor or other hard substrate because leg and foot injuries can result. Please let us know how this progresses. The Regal Swan