There is a mute swan who appears sick. The swan was sitting on the sidewalk allowing people to pass by within 3 feet with no aggressive response. The mate was swimming a good distance away. Three hours later I found the swan sitting beside the lake panting and water dripping from the front of the beak. I took water from the lake into a bowl and placed it in front of the swan and it did not attempt to bite me or even act aggressive. The swan immediately drank from the bowl of water and then got up and leaned over and drank from the lake and then got in and swam with its mate. The mate swam over to me and did not attempt to attack me. I am going to check on it tomorrow. I also gave it lettuce but it did not seem interested in it. What does a mute swan eat? Should I call a bird rescue? Are there any problems that could arise to my health being around a sick mute swan?