Photograph by Bjorn Larsson Rosvall, AP
It was while I was driving home, having dropped my son off, I began think of the “weird” happenings over the last week or so regarding our feathered friends. Namely the seemingly inexplicable regularity that birds seem to be literally raining from the sky, and the accompanied explanations ranging from fireworks to UFO’s,:-
- New Year’s Eve Arkansas 5,000 red winged black birds, European Starlings.
- 500 dead blackbirds were found dead, this time in Louisiana (3rd January 2011)
- Thousands of Turtle Doves Italy (5th January 2011)
- Sweden, dozens of Jackdaws……..
So here is my attempt at an explanation……….
A few years ago I use to teach Foundation Degree Environmental Science, a variety of topics were covered including “Pollution” in the environment. As is commonly know there are a wide variety of pollutants and sources and ways in which pollutants travel through the environment. One of these being Bioaccumulation and biomagnification, that being the ability of very small levels of pollutants to make their way into the environment, accumulating (again in small quantities) in micro-organisms and slowly via the food chain increasing in quantity (biomagnification). Many pollutants such as heavy metal(cadmium, lead, zinc) and chlorinated hydrocarbons and so on are hydrophobic (don’t like water) and will tend to accumulate in sediments or if they enter an organism within the organs and “fatty” tissues.
This is were my theory comes in, I believe the birds that have died may have accumulated these toxins over the previous months and days by feeding on pesticide ridden crops and food, but only accumulating small quantities at a time, at levels below a critical toxic level.
The second part of my theory needs the help of one of the coldest winters in 150 years. During these kind of conditions, food is in short supply and the birds own system starts to tap into its bodies own reserves of energy i.e its fat. In doing so I believe this released a surge of toxins in to the birds system, causing a toxic reactions. Many of the birds have been described as “acting drunk“, and the Turtle Doves in Italy reportedly had blue around their beaks, a classic sign of poisoning “Travis Walter Donavon wrote “blue stains found in mouths of the dead and dying birds in Italy could be the result of poisoning or possibly signs of hypoxia,” which is a lack of oxygen in the body”.
What about the limited area over which the bird are falling over I hear you say? well again I believe this to be due to the sudden surge of toxin being released, this time during the exertion of the birds during flight. Assuming that these birds( being flocking birds) will most likely feed on the same food supplies, over a similar time period and having a similar routine could account for the toxic surge occurring within group of birds within the same flock at the same time?hence the localised extent over which the birds fall. I would also suggest that the reference to blunt -force deaths i.e hitting or being hit with something hard is most likely explained by the birds actually hitting the ground?