Researchers still don't know why tens of thousands of birds vanished suddenly two years ago from the Florida Gulf Coast's largest colony.
They only are beginning to understand the ramifications.
New University of Florida research shows cottonmouth snakes have declined significantly since the birds abandoned the island.
Lead author Mark Sandfoss says the snakes' health and population have deteriorated. He says it is one example of how the abandonment has affected the island.
"Certainly this kind of influx of nutrients from all the birds and the guano will have impacts on the amount of nutrients in the system, which could impact invertebrates, which could impact the whole ecosystem in a negative way."
Thousands of egrets, pelicans, roseate spoonbills and other species relocated to a nearby island, but researchers still don't know where most of the birds went.
