Hobbies And Interests
Documented Cases
In 2010 alone, the United States Geological Survey (USGS) recorded eight separate die offs, each involving the deaths of at least 1,000 birds. The causes included starvation, parasites, avian botulism and Newcastle disease. Over a 10-year period starting in 2000 and ending in 2010 there have been over 188 bird die offs recorded in the United States with a minimum of 1,000 deaths per event. In one instance, over 50,000 birds died in Utah from botulism and another 10,000 birds died in Washington from a toxic algal bloom.
Fireworks
On New Year's Eve of 2010, 5,000 blackbirds fell from the sky and died in Arkansas. Tests showed no sign of disease in the birds, reported The New York Times. Neither were there any poisons or toxins present. However, according to a biologist, the likely cause of the sudden die off was due to fireworks that were set off in a nearby town close to where the blackbirds had their roost. The startled birds were frightened and flew in one direction at a level much lower than normal. Due to their poor night vision, the birds crashed into obstacles such as cars and buildings. Cause of death was from physical trauma to the chest and brain.
Salmonellosis
Wild birds sometimes die from salmonellosis, which is a bacterial disease. The most common species of salmonellae in wild birds is S. enterica sv Typhimurium. It affects many types of birds around the world. In Michigan salmonella has been found in a variety of birds including the blue jay, herring gull, purple finch, tree sparrow and great blue heron. Two large and sudden die offs of herring gulls took place in Michigan in 1970 and 1977. The disease is transmitted through food contaminated with fecal matter and the outbreaks often occur in winter around bird feeders. Because of their feeding habits and tendency to gather en masse around the feeding area, house sparrows are vulnerable. The ground becomes contaminated and there is greater chance of exposure to the bacteria. Symptoms include loss of appetite, shivering, fast breathing, bloody droppings and sudden death.
Avian Cholera
Avian cholera in wild birds is most commonly caused by the type 1 strain of Pasteurella multocida. The infection is spread from one bird to another through direct contact as well as through bodily secretions and fecal matter. Birds can also become sick when eating contaminated food or drinking contaminated water. This hardy bacteria is able to live in water and soil for up to four months. Avian cholera causes large and sudden die offs mostly in geese and wild ducks. Death can occur so quickly that the birds actually fall from the sky. Warning signs include flying upside down, swimming in circles and convulsions.