USGS and a network of partners across the country work on documenting wildlife mortality events in order to provide timely and accurate information on locations, species and causes of death. This information is used by natural resource managers, researchers, public health officials and legislators to help design disease prevention and mitigation strategies, to address interconnections between human, domestic animal and wildlife disease, and to assist in identification of 'normal' disease issues vs. biosecurity concerns.

These data are not all-inclusive. Information on some outbreaks may not be received until months or years after the event, but efforts continue to make the information as complete as possible. For information on previous wildlife mortality events and events that used to be on this page, please see the Quarterly Mortality Reports.

While the media has put a spotlight on mass animal deaths, there is nothing unusual about them.

"There's been an unusual amount of attention on this type of thing which does occur quite frequently," said Inkley. "Most mass mortality events in wildlife are caused by disease, some are caused by pollution, such as the Gulf oil spill disaster and some are caused by freak accidents."

Although the string of animal die-offs are unrelated, Inkley said climate change is the true cause for concern.

"Some 20 to 30 percent of species in the entire world could be moved a step closer to extinction by 2050 due to climate change," said Inkley.

Throughout history, animals acting strangely have been predictive of tragic events. Most of us remember the devastating tsunami that hit Eastern Asia in 2004. After the horrors of the tragedy began to unfold, some scientists and other experts pointed out the surprising lack of dead animals during clean-up. This wasn’t the first case where animals can sense something and take off, but it certainly was one of the biggest examples of wildlife’s sixth sense. According to a 2400-year-old document, ancient Greeks observed animals abandoning the city of Helice before a destructive earthquake destroyed it. This is one of the earliest known reports, but there are countless other examples and tales of strange animal behavior prior to a natural disaster.