Hello, I was just at the Westin Hotel in Kaanapali, Maui in Hawaii where they have a black and white swan swimming on their ponds as display for the guests. A group of adults and children were throwing long pieces of white food? Perhaps bread or chips to feed the black swan. They were also taking pictures of the black swan's face from very close proximity with the flash on. When they left the black swan started shaking his head continuously for about 30 minutes (almost nonstop). We talked to the manager and other employees several times. We called the 24 hr animal clinic nearby but they would not help because the swan does not belong to us. We will go back again tomorrow to check on the swan. The manager told us the men that maintain the grounds take care of the swans but that they are not veterinarians. I cannot find any information online about why black swans shake their heads. The swan looked like it was choking or struggling to swallow something. Is this normal behavior? What can we do? I took a video of the swan's behavior if you would like to see it. Thank you.