They found that fed stingrays swapped their normal nighttime foraging for daytime feeding, and in contrast to their wild counterparts, began to rest at night. They also didn't mind rubbing shoulders with their neighbors: At least 164 stingrays abandoned the species' normal solitary behavior, crowding together in less than a quarter square mile of space at Stingray City. They even formed schools and fed together. The fed stingrays mated and became pregnant year-round, instead of during a specific mating season, and also showed signs of unusual aggression, biting each other more frequently than their wild counterparts.
These results suggest that human-provided food can dramatically change how even large, highly mobile ocean animals behave with potentially serious consequences, the researchers conclude.
"There are likely to be some health costs that come with these behavior changes, and they could be detrimental to the animals' well-being in the long term," Shivji said.
Stingray City means big business in the Cayman Islands, where each stingray generates as much as $500,000 annually in tourism income, Harvey said. The team plans to continue to monitor Stingray City's population to track its health and the industry's impact over time.
"Right now, these animals have no protection at all," Harvey said. "Without more studies like these, we won't know what that means for the wildlife or if we need to take action. It's unclear how much of the stingray's daily diet comes from tourism provided food, but the good news is we have seen the animals forage when tourists are absent suggesting that these animal are not completely dependent on these handouts."
|Contact: Ken Ma|
Nova Southeastern University