There’s a special providence in the fall of a sparrow

Contact: Jonathan McKnight, Maryland DNR | 410-260-8539

John J. Mosesso, National Biological Information Infrastructure, Bugwood.org

ANNAPOLIS, MD (March 21, 2006) – Given time, Shakespeare's reference to the House Sparrow might have been its ticket to a new world, for in the 1800's various American literary societies made an effort to introduce all of the birds mentioned in Shakespeare's works to North America. But in the case of the House (or English) Sparrow, literary motivations appear to have been preceded by biological experimentation. Like so many others, this invasive exotic species was brought to the new world from the old in order to battle an agricultural pest, the cutworm. By the time of the heyday of introductions of Shakespeare's birds in the 1890's, there were already millions of House Sparrows in the new world.

The House Sparrow is not a true sparrow as are the dozens of less-familiar North American sparrows, but a weaver finch, one of a family of old world birds known for weaving their nests. House Sparrows are ubiquitous in North America. They are also common in many parts of South and Central America as well as Europe, Asia, Africa and Australia.

In Maryland, house sparrows nest in every county and in nearly every habitat, with the exception of expansive marshlands and barrier islands, although their numbers are more concentrated near urban centers. The all too familiar House Sparrow has been selected as the “Invader of the Month” for March by the Maryland Invasive Species Council.

Brash, bold, and well-adapted for living among human habitation, the House Sparrow can be found scavenging for discarded fries in fast-food restaurant parking lots, hopping about in urban parks and streets, and living in warehouse-style home repair retailers, where it thrives on spilled grass seed. House Sparrows have such a long and interwoven history of consorting with mankind that it is thought that the species actually abandoned its previously-migratory behavior with the advent of agricultural civilizations in the Middle East, choosing instead to remain with a new and steady source of food.

House Sparrows scavenge farm fields and grain facilities, earning the ire of farmers. But from an ecological perspective, it is the nesting behavior of the House Sparrow that makes it a dangerous invader. House Sparrows are a cavity-nesting species; that is, they nest in holes in trees or similar structures like birdhouses. Many native birds, including bluebirds, are also cavity nesters. House Sparrows are extremely aggressive in their nesting behavior and will evict the eggs and chicks of native birds from their nests, often killing adult bluebirds who attempt to defend their young.

Among the spectrum of North American invasive species, English Sparrows are probably a lost cause in that they appear to be so common and widespread that there is little hope of ever removing them from the landscape. American farmers and our native birds are stuck with them for the foreseeable future. Recently, however, eastern populations of this species seem to be declining – markedly so in Maryland – probably as a result of new agricultural methods which leave less grain in fields after harvest. It remains to be seen whether or not falling sparrow population numbers represent Hamlet's "special providence" for native wildlife.

For more information about House Sparrows and other Invasive Species of Concern, visit the Maryland Invasive Species Council.