Cause of Peculiar Bird Deaths Established

Scientists at the United States Geological Survey (USGS) announce that they were finally able to determine the cause that led to the mass death of birds in Arkansas and Louisiana on New Year's Eve.

According to the investigators, most of these animals were killed by impact trauma. The team that conducted the work also says that large die-offs are not uncommon for wildlife, and say that this type of events should be considered as a health indicator for ecosystems.

Birds that died in Arkansas were analyzed at the USGS National Wildlife Health Center, whose preliminary conclusions were in tune with the ones set forth by the Arkansas Game and Fish Commission, in a statement.

The main explanation for this type of trauma in those specific circumstances was that the loud noises that were produced that night, as people were celebrating their passing into the new year, startled the animals, making them restless, and forcing them to fly into houses, trees and other objects.

USGS NWHC studies revealed a negative toxicological report, meaning that pesticides and other chemicals were not responsible for the event. Necropsy of the dead Arkansas birds revealed internal hemorrhaging, which is consistent with the trauma scenario.

These are only preliminary results, scientists say. Full lab results are expected to be publsihed within 2 to 3 weeks, when experts will know more about what happened.

“Although wildlife die-offs always pose a concern, they are not all that unusual. It's important to study and understand what happened in order to determine if we can prevent mortality events from happening again,” explains Jonathan Sleeman.

The expert holds an appointment as the director of the Madison, Wisconsin-based USGS NWHC. The lab is completing the analysis of both Louisiana and Arkansas birds.

According to official statistics from the National Wildlife Health Center, there were 8 animal die-off events in 2010, that involved 1,000 birds or more in each instance. Starvation, avian cholera, Newcastle disease and parasites were among the main causes for these events.

“According to USGS NWHC records, there have been 188 mortality events across the country involving 1,000 birds or more during the past 10 years (2000 – 2010),” the USGS reports.

“In 2009, individual events included one in which 50,000 birds died from avian botulism in Utah; 20,000 from the same disease in Idaho; and 10,000 bird deaths in Washington from a harmful algal bloom,” the Service adds in a press release.