Hello LIFEers. This week Professor Tim Sebesta came to our LIFE class to warn us that we are being invaded! They’re already here! No, it’s not the pod people, but birds, millions and millions of birds invading our towns and countryside. And while they aren’t attacking us directly, like Hitchcock would have you believe, some are threatening our native birds, crops and ecosystems. Hence the class’ title, “Are you a good bird, or a bad bird?”
Did you know that in North America today there are nearly 100 alien bird species? This includes game birds and escaped pet birds. Some alien birds got here on their own, such as the Old World Cattle Egret, which arrived in South America around 1880 and in Florida around 1940. It now thrives in the cow pastures of the southeastern US. Other species were brought here and released deliberately, such as the European Starling. In 1890, Eugene Schieffelin, a wealthy businessman, released 60 Starlings in Central Park, and then another 40 the following year. Today, Starlings live coast to coast, from Alaska to Mexico, with an estimated population of over 200 million.
Another introduced bird is the House Sparrow. People brought it to the US because they thought it was pretty and that they would control pests. After being introduced to North America in 1850 in Brooklyn, NY, it took only 50 years to spread across the US. But not all birds that are introduced to a new area are considered invasive. Out of the most familiar introduced bird species; European Starling, House Sparrow, Common India Myna, Mute Swan, Rock Pigeon, Ring-Necked Pheasant, Eurasian Collard-Dove and the Monk Parakeet; the last three are not considered invasive.
The Sparrow, Pigeon and Starling are considered the most invasive and damaging to the US. The Starling damages crops and livestock feedlots, the Pheasant eats sprouting corn, Starlings make dirty and smelly nests in cities, and all birds living in cities foul structures with droppings. It is believed that many years of bird droppings may even have contributed to the highway bridge collapse in Minnesota; the acid in the droppings accelerating the corrosion process.
So why are these birds thriving here? It is a combination of factors; they fight aggressively for territory and food, and reproduce more quickly. Meanwhile they kill or inhibit the reproduction of native species, bring parasites and diseases, contaminate our food storage facilities and are responsible for over $4.5 million in damage to aircraft.
What can you do about this invasion, you ask? You can start in your own backyard. First target: food. If you have birdfeeders, try to use thistle, safflower seeds, suet, nectar or fruit and nuts for food. Avoid corn, wheat, oats, millet and bread scraps, which are favored by invasive species. Avoid hopper-style feeders, platform feeders or putting food on the ground. Instead use clinging mesh feeders, sock or tube feeders with perches shorter than 5/8 of an inch, or feeders with weighted perches. Hanging style feeders that sway in the breeze are also good deterrents to invasive species. Finally, stop feeding in the summer. Food is abundant this time of year, and by providing food you are probably encouraging the spread of the invasive species. Feed only the winter when food is scarce.
Second target: minimize their nesting areas. Fill in gaps in your house, usually in eaves under the roof, by using 19 gauge hardwire cloth. Birdhouses with small openings will prevent the spread of Starlings, but won’t stop Sparrows. Third, you can trap invasive birds and destroy their nests and eggs. Last, be a good egg and inform your family, friends and neighbors about invasive birds so they can join the effort to minimize their spread.
See you next week!