Having just made it through winter and the usual flu season, it is disturbing for most of us to learn that another form of flu has reared its ugly head and has been spreading like wildfire. This one though is targeting birds – domestic turkeys and chickens mainly. At the moment this is an economic disaster for individual growers, who have had to watch their flocks quickly sicken and die, and then as a precaution have had to destroy the remaining birds.
Avian Flu (also known as Bird Flu) has likely been in existence for centuries, but in the 20th Century it began to appear with some regularity in domestic birds around the world. There are 16 known Avian flu types. It wasn’t until the virus began to genetically mutate and begin to sicken humans that it took on the level of concern that we know today. The most famous and deadly human infection happened in 1918 when H1N1 mutated and killed over 500,000 people in the U.S. an estimated 50 million worldwide. The most recent human contracted outbreak occurred in 2013 in China. Naturally there is great concern whenever Avian flu appears, but most of the viruses that are deadly for birds are not necessarily the same for us. The current strain that is killing domestic fowl is H5N2.
There is much that is not known about bi rd flu. How it spreads is the greatest concern and is riddled with uncertainty. It is believed that domestic fowl are somehow exposed to the virus from wild birds. Research has shown that it is mostly wild waterfowl and raptors that carry and suffer from the disease, although some can be carriers and not exhibit symptoms. The virus is transferred through body fluids and droppings. The droppings can easily contaminate food, soil, machinery, tools and water. From there it is an almost impossible task to contain the spread.
Wild waterfowl typically feed and travel in flocks and it is this behavior of close association that makes it easy for the virus to spread and mutate. When these flocks migrate in the spring they can land on ponds or in fields near domestic fowl. Since the vast majority of our domestic turkeys and chickens are housed in high-density cages or buildings there is little to stop the spread of the flu once it has been introduced. Because crowding leads to stress, the birds may already have weakened immune systems, making them even more susceptible. People can inadvertently introduce the virus too, by carrying it on their shoes, clothing, or car and truck tires.
It’s harder to explain why raptors are found with this type of virus since they are mostly solitary, but they are predators and waterfowl are prey for many of them. Eating an infected duck or goose could also make the raptor sick. To determine if a wild bird has one of the strains of Avian flu, someone must find a dead bird and take it in to the proper Agency to be tested. This happened recently in Wisconsin when a dead snowy owl tested positive for H5N2. From outward appearances the owl did not look sick. This was the first wild bird in Wisconsin to be found with the virus. In April, a Coopers Hawk found in Yellow Medicine County, Minnesota tested positive for the virus.
Iowa, Minnesota and Wisconsin have been especially hard hit in this recent episode because they have some of the largest turkey and chicken facilities. Two of the largest turkey farms housed more than 300,000 birds each. One chicken facility held 5.7 million birds, two others held more than 3 million. The most recent figures indicate that 28 million turkeys and chickens have died or been killed. As enormous as that sounds, it is only equal to less than three-tenths of one percent of the total birds being raised for meat or eggs in the U.S. Still, because of the economic impact on the rural areas in particular and the need to contain the spread of the disease, a state of emergency has been declared in the three states mentioned above.
While we might see a slight increase in the cost of eggs, farmers will be replacing their flocks as soon as possible, and expect it will take six to nine months to get back on a regular laying schedule. We are told there won’t be a shortage of turkeys for Thanksgiving.
For those of us who enjoy feeding by wild birds, there is little to be worried about. You should try to keep your feeders clean, scrubbing them with soap and water (some recommend bleach – just be sure to rinse thoroughly) periodically, especially those that are platforms and could have droppings on them. If for any reason you handle a bird – say one that flies into a window, either wear gloves or make sure you wash your hands thoroughly afterwards. This should be standard practice at any time.
We feel great sympathy for the farmers and the birds who are suffering through this most recent outbreak of Avian flu, and hope it will soon be in our past, but do not let it lessen your birdwatching pleasure at this most wonderful season of the year.
By Kate Crowley