Birds fall out of the sky. Dead fish wash up on shores all over the world. In the past week news of mass animal die-offs inundated newspapers and the blogosphere. While sad and worrying to a certain extend, experts say the events are not abnormal.
The death reports started a few days before the end of 2010: roughly 85,000 fish died near Ozark in Arkansas. A rain of dead birds followed with thousands of red-winged blackbirds falling out of the sky over the town of Beebe, also in Arkansas, on New Year’s Eve. Further reports ensued. Hundreds of dead birds found in Louisiana, 50 to 100 jackdaws perished in Sweden, tens of thousands of dead fish washed up on the shore on the Maryland coast of Chesapeake Bay, more than 40 thousand dead crabs showed up on Kent beaches in the UK. The list goes on.
While conspiracy theorists may feel an urge to connect these happenings, to point aliens or government experiments as culprits, or to take them as a sign of the end of the world, experts have a different opinion.
Most, if not all, of the mass deaths of animals reported last week have already been explained by scientists. The birds in Arkansas and in Sweden died from blunt-force trauma, likely caused by fireworks. Almost all of the Ozark fish were drum, pointing a species disease as a possible culprit. The birds in Louisiana had broken beaks and backs indicating that they may have flown into a power line or another tall object. The death of the Maryland fish and the Kent crabs, on the other hand, is blamed on the cold weather.
Moreover, events where thousands of birds die at once are not at all uncommon. Death can be caused by starvation, disease, pesticides or collision with man-made structures such as wind turbines and cell-phone towers. Weather phenomenon like snow, hail or lightning can also kill flying birds.
Fish kills are also not unusual, particularly in the winter when fish are grouped more closely and extreme temperature fluctuations are more common. Dead fish can also wash up on shores if fished and subsequently dump in the sea, either accidentally — due to a net splitting, for example — or purposefully. Most countries have limits on the amount of fish caught and fishermen may discard their excess cargo if in risk of being caught by authorities.
What happened in recent weeks “is a classic example of freak events coinciding”, said Petter Boeckman, a zoologist at the Norwegian Natural History Museum, quoted by Reuters. In the era of instant global communications, there has simply been more media hype around this type of occurrences than in the past.
Nonetheless, birds and other species are indeed in trouble, but not because of some sort of “aflockalypse” — the term used to describe the bird die-offs in some circles. If there is anything to worry about is the fact that many species (one in six in the case of birds) are threatened with extinction, mainly due to man-related causes.
As Melanie Driscoll from the Audubon conservation society puts it, “far more concerning in the long term [than recent bird deaths] are the myriad other threats birds face, from widespread habitat destruction and global climate change to inappropriate energy development and invasive species.”