Global IssuesBird, Fish Kills Quite Common - and That's the Problem
The New Year brought a spate of incidents across the United States and around the world in which large numbers of birds appeared to have fallen out of the sky, and thousands of fish were found floating dead in rivers.
As media reports multiplied of mysterious mass wildlife deaths, and blogs and social media picked up on the story, the inevitable theories began circulating, ranging from the outlandish (a sign of the apocalypse) to the more plausible (a consequence of environmental damage, such as the U.S. Gulf Coast oil spill of 2010).
In the end, while the reasons appear to have varied, scientists say such deaths are a normally occurring phenomenon — and that is precisely why people should be concerned.
'We somehow think we can put up power lines, cell towers and high-rises and wildlife will just fly around it,' Karen Rowe, bird conservation programme coordinator for the Arkansas Game and Fish Commission, told IPS.
On Jan. 1, residents of Beebe, Arkansas, awoke to find about 5,000 dead blackbirds lying on the ground. Then, on the state's Arkansas River, 80,000 drum fish were found dead.
On Jan. 3, residents of Maryland's Chesapeake Bay area began reporting tens of thousands of small fish, including menhaden, spots, and croakers, washing up on shore. Officials believed it was due to cold weather. The following day, dozens of dead birds were spotted by a Gilbertsville, Kentucky woman in her backyard. More were found at nearby Murray State University.
Also on Jan. 4, about 500 dead blackbirds and starlings were found in Labarre, Louisiana, and thousands of dead mullet, ladyfish, and catfish were found in Spruce Creek, Florida. Several dozen birds, including American coots, were found on Jan. 5 on a Texas highway. About a hundred starlings were found dead on Jan. 10 near a highway in northern California.
Then on Jan. 11, thousands of gizzard shad fish were found in Chicago, Illinois, followed by 300 dead starlings in South Dakota on Jan. 18.
Bird deaths were also reported in Falkoeping, Sweden, on Jan. 4; Peterborough, England, on Jan. 4; and Faenza, Italy, on Jan. 7. Fish deaths were reported in Parana, Brazil, throughout late December and early January; in Sarnia, Canada, in early January; and Little Bay and Waikawau Bay, New Zealand, on Jan. 4.
Rowe and Tom Sherry, a professor of ecology and evolutionary biology at Tulane University in Louisiana, both told IPS these types of incidents are actually quite common.
Indeed, according to the U.S. Geological Survey National Wildlife Health Center, in the last decade, 175 mass deaths exceeding 1,000 birds have occurred in the United States alone.
Bird die-offs would happen without human activities like industry, Sherry said, but human activities are making it much worse, and we are starting to see what he refers to as the 'cumulative impact' of numerous problems.
Rowe studied the Beebe incident and concluded that the birds died from being scared from their roost at night by fireworks.
'You have to understand what fireworks do,' Rowe said. 'They don't see very well. When the birds heard these noises, we strongly believe they flew up into the air. A portion of them came down, [and] they collided into buildings, houses, trees.'
'It was the noise of the fireworks that caused them to leave the roost, but the cause of death was trauma from flying into objects,' she said. 'All three labs found trauma injuries, hemorrhages to the chest, head, and the wings, consistent with flying into something rather than falling.'
Prof. Sherry looked into the reports of dead birds in Labarre, Louisiana, and noted in almost all the cases, the dead birds were found within a few yards of power lines. Sherry believes the birds were flying low due to a storm event, and again, blackbirds cannot see well in the dark, so they collided with the power lines.
Meanwhile, the U.S. Department of Agriculture admitted guilt in the South Dakota incident; it had deliberately poisoned the birds after a local farmer complained.
'In any month of the year, there are several ongoing mortality events that go on across the nation. Wintertime is a stressful time for wildlife,' Rowe explained.
'Birds are colliding with power lines, communication towers, high-rise buildings. Those are species suffering declines,' Rowe said. 'How many birds are we willing to see die because we're going to place a new cell phone tower?'
Sherry noted that some scientists have lobbied the Federal Communications Commission to change the lighting on communications towers, to prevent birds from flying into them.
'If they would just change the light from a red light to a white strobe light, bird mortality could be reduced by 75 percent,' Sherry said.
'There's a variety of lighting techniques that can help the birds avoid towers, miss buildings. We have to focus on how to mitigate the impacts on the migrating birds,' Rowe said.
According to a report by the U.S. Fish and Wildlife Service, Division of Migratory Bird Management, there are ways bird mortality could be mitigated. While the law gives them the power to pursue prosecution for threats to migratory birds, the agency has instead chosen a softer approach.
'We support initiatives such as the Cats Indoors Program and the Fatal Light Awareness Program, which encourages building owners to turn off skyscraper lights during spring and fall night-time songbird migrations,' the Service wrote.
As for the fish kills, Sherry said freezing cold temperatures was a plausible explanation for some incidents, adding that some of this winter's extreme cold and blizzard conditions across the United States could be due to climate change.
© Inter Press Service (2011) — All Rights ReservedOriginal source: Inter Press Service