By Sarah Harper Diaz
The House Sparrow was first introduced to the United States in the 1850s. One man bought 100 individuals from England and released them in Brooklyn, NY. After a few more small introductions in the 1800s, including San Francisco and Salt Lake City, the population of the House Sparrow exploded in the New World. It now ranges across the entire continental US, Hawaii, Puerto Rico, Central America, parts of South America, and most of Canada. The success of the House Sparrow is largely due to the fact that it thrives around human development. It will nest in a variety of crevices in man-made structures but will also occupy natural cavities that would otherwise be used by native species. House Sparrows are seasonally monogamous and a single pair will often have between three and four successful broods in one breeding season! Females start laying eggs as early as March and lay about five eggs per clutch. The young hatch out helpless and naked, but they grow rapidly and fledge in only two weeks. House Sparrows are considered an agricultural pest as well as a significant threat to native bird species. They will frequently occupy bluebird nest boxes and entire Purple Martin houses.