(Note: photo courtesy of Lila Arnold)
The European Starlings are molting into their winter attire. In the summer, they appear predominantly brown--I think because so many are young birds (they have a very high survival rate). Right now they are an odd combination of winter and summer with speckled breasts and brown backs and wings. Soon they will be a glossy black with spots all over them.
The starling is a very successful introduced species. Today some 200 million starlings make their home in the United States from an original release of about 100 individuals in New York's Central Park in 1890 and 1891. This is not a good thing for our native cavity-nesters as starlings are intensely competitive for these nesting sites.
Although I think of starlings as year-around residents, many starlings do migrate. They tend to be associated with urban areas and agricultural crop land--areas with short vegetation. They avoid large areas of woodland or desert. They will eat almost anything. Although invertebrates (especially those which live in the soil) are their favorite food, they eat fruits and berries, seeds, garbage, and livestock and pet food. Their diet is almost exclusively invertebrates in the summer and more plant foods in the winter.
I was reading the account on starlings in Cornell University's Birds of North America (http://bna.birds.cornell.edu/bna) and found it interesting that the digestive system of the starling changes with the change in diet:"The digestive system of starlings can respond to changes in diet to make more efficient use of a seasonally variable food supply. After switching to plant food, the gut lengthens, the gizzard becomes larger, and the intestinal villi lengthen (in Feare 1984). The rate of food passage through the gut also increases (Levey and Karasov 1989)."
I am always amazed what information you can find on Birds of North America--I didn't know that starlings cannot digest sucrose or that they prefer green nesting materials.
I don't care much for starlings, mostly because they are very aggressive in seeking cavities to nest and will evict many of our natve birds. Among them: wood ducks, buffleheads, woodpeckers, bluebirds, great crested flycatchers, purple martins, and tree swallows. Since there are many other small burds that use bluebird boxes to nest, I assume they would also interfere with them: wrens and chickadees for example. However, you have to admire their ability to be so successful in the scheme of things.
Unfortunately, there is not a good deterrent for starlings--they adapt fairly quickly. I don't often have any starlings in my yard, but I don't maintain a beautiful yard either. My neighbors have them; I see them as I drive by. But I rarely have any. Sometimes in the winter I will have one or two show at the feeder. But my yard has a lot of bushes, tall grass and trees and very little grass. There are good things about being the neighborhood yard pariah.