Monday, April 25, 2011

House Sparrow

House Sparrows (Passer domesticus) is a small non-native bird that resides near human dwellings. Its species name of domesticus even hints at its preference for associating with human activity. They are native to Europe, Asia and parts of the Mediterranean and have been introduced throughout the World, both purposely and accidentally. They are perhaps the most widely distributed bird species in the World.

House Sparrows aren’t related to other North American sparrows, and they’re differently shaped. House Sparrows are chunkier, fuller in the chest, with a larger, rounded head, shorter tail, and stouter bill than most American sparrows. So these gregarious birds should not be mistaken for native species of sparrows. The house sparrow competes for nesting sites with native birds and often displaces them. Bluebirds are especially targeted by this bird, house sparrows will enter the bluebird house and peck holes in the eggs or kill the babies. They also take over purple martin houses, chick-a-dee houses and any other birdhouse they can fit into. I noticed one the other day in my own backyard trying to fit into a wren house entrance. It's eyes seriously misjudged the diameter of the hole, compared to the size of its own body. She worked and worked at trying to fit. I had to admire her for the positive attitude...kind of like a woman who is convinced she can wear a pair of jeans one size smaller, and will do everything she can to make them fit!

I personally do not tolerate house sparrows and as soon as I discover nests in my bluebird houses or other bird houses I destroy the nest, eggs, and any nestlings. I admit this is an ongoing battle and I find myself clearing out a nest almost daily for over a month or more. Some people may find this cruel to the bird, and cannot imagine killing any bird, and that is fine. If you prefer to let them take over your nest boxes and breed and add to the ever growing population of house sparrows then that is your choice. I for one prefer to give the native species a fair chance. House sparrows and starlings are two species of birds that are not protected under the migratory bird act, or by any other Federal or state laws. They are much more aggressive than the smaller nesting birds that typically fall victim to the house sparrow invasion. I do however have a pair that takes up residence in my clothes line pole every year, and I leave them alone. Mostly because they are not invading the bird houses.

Birdwatchers have no particular love of house sparrows and that comes back to the invasive tendency of the species. These birds feed on a wide variety of seeds and other foods. They are very fond of wheat and oat seeds and will often invade fields in large numbers. Farmers often shoot, bait or trap the adults to keep them out of their fields. Sparrows are also known to spread diseases such as West Nile and Salmonella to humans and to livestock, which is one more reason they should not be tolerated in large numbers.

House sparrows do have natural enemies in the form of birds of prey, in particular American Kestrels. Cats will also capture many house sparrows. In Europe they are often victims of roadkill and in parts of the Mediterranean humans feed on them as part of their normal diet.

House sparrows were introduced into the United States in 1851 in New York to help control caterpillar populations. After the initial release there were many subsequent releases in various parts of the country, with each release they became more and more established. They have now spread their range throughout all of the United States. They are listed as a species of least concern with the IUCN because of their large population and range. These birds return to their birthplace after every migration (a characteristic known as philopatric). Because of this, local populations have adapted to the color of their habitat resulting in 15 distinct subspecies in the West.

Depending upon how you feel in regards to these little birds, you may want to implement a control plan on your own property. This is especially true if you have bluebird houses.

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