This is normal behavior. Some researchers believe that not only is this a resting position, but also a means to dissipate heat. Swan feet have many blood vessels which can displace heat and help cool the birds.

As far as the food, too much protein can cause angel wing also known as reversed, backward or slipped wing. The condition occurs when the wings develop faster than the supporting tissues. The weight of the wings causes the wings to droop or reverse backwards. It is for this reason that we advise feeding swans a 50% mixture of cracked corn and 50% poultry layer pellets. The cracked corn provides crucial Vitamin A that helps prevent neurological issues as well as acts as a filler. The poultry layer pellets provide necessary vitamins and minerals, and micro-nutrients. Also, add chopped lettuce to provide them with necessary vegetation. A treat of small amount of bread will also help them get used to the lettuce.

Slipped tendons of the legs will result in a splaying appearance in the legs and the birds cannot support their weight and walk. If the condition is observed, the bird needs to be examined by a licensed experienced avian (bird) veterinarian. This is a difficult condition to correct and treat. This condition can be prevented by keeping all waterfowl, regardless of age, off of slick, abrasive and steep areas. Also, one must be very careful in how the birds are handled as the legs can easily be splayed from improper handling. The
Regal Swan