Between the news reports, Jon Stewart’s repeated references on The Daily Show and animal-costumed Saturday Night Live cast members, I’m sure I don’t need to tell you about the recent wildlife die-offs spinning news media and public alike into a tizzy. One thing repeatedly mentioned in these news stories is the statement from wildlife officials that mass mortality events are fairly common. Well, I decided to take a look. Below you’ll find the quick and dirty breakdown by the numbers. Warning, this might be my “Debbie Downer-ist” blog post yet.
USGS National Wildlife Health Center Mass Mortality data for 2010-present, represents only the Lower 48
72: Wildlife die-off events in the past year
29: States where these events occurred
8,560: Most deaths in one state (Minnesota), mostly waterbirds from a mix of toxins, parasites and viruses
10: Number of mass die-off events in Minnesota last year
4,300: Largest die-off event in 2010
13: Die-offs with 500+ deaths
85: Percent of total mass-mortality events that involved birds
10 Largest Mass Mortality Events 2010-Present | Approx. # Killed | Cause | |
Minnesota | Waterbirds | 4,300 | Parasites |
Arkansas | Red-winged Blackbirds | 3,000 | Trauma |
California | Northern Fulmar | 2,750 | Emaciation |
Texas | Brazilian Free-tailed Bat | 2,000 | Rabies |
Idaho | Tiger Salamander | 1,500 | Virus |
Minnesota | Waterbirds | 1,450 | Virus |
Minnesota | Waterbirds | 1,200 | Parasites |
Florida | Vultures and Hawks | 900 | Drowning, Emaciation |
Minnesota | Waterbirds | 800 | Open Investigation |
South Dakota | Waterbirds | 700 | Botulism C |
Michigan | Gulls | 700 | Botulism E |
Some Interesting Notes:
- Species of waterbirds appear to be the most frequent victims of mass die-off.
- Bats suffering from white-nosed syndrome were not represented in USGS data.
- Data does not include several mass fish death events from the past year, including more than 100,000 in the Arkansas River in 2011, 20,000 menhaden in Hampton Roads, Virginia, July 2010; 100,000s menhaden on Folly Beach, South Carolina, as of January 7, 2011.
- Also notably missing from this data appear to be wildlife mortality events from much of the Gulf Coast.
















