By Jeanne Church
Just outside my kitchen window, in the low-cut yews below the sill, the house sparrows have gathered once again; singing and chattering among themselves, making a cold, dreary day seem like spring. Even though house sparrows are with us all year, they don’t seem to congregate in the yews until the colder weather sets in. I love hearing them sing, especially in the dead of winter. Their songs and playful antics bring me joy, but I have come to learn that they do not bring joy to everyone.
House sparrows are an invasive species. They were introduced to our country in the late 1800s by a young immigrant named Nicholas Pike, who thought these birds would make a lovely addition to our landscape, and that they would eat our insect pests. Pike only released 16 birds, but within 30 short years, those 16 birds became thousands, and were considered a serious agricultural pest as well as a significant threat to our native birds. Other immigrants besides Pike also considered the house sparrow to be a pleasant reminder of their homeland and brought the birds with them wherever they settled throughout the world, including Australia, Africa, and the rest of the Americas. As a result, the house sparrow is now considered the most common and widely distributed of all wild birds across the globe!
The house sparrow owes its magnificent success to its incredible adaptability. It has managed to thrive in virtually every environment where it has been introduced among humans. In fact, it prefers to live among humans! You will not find house sparrows in uninhabited areas. They like to make themselves at home by building their nests in our eavestroughs, walls, and streetlights, as well as our manmade nest boxes. The house sparrow’s propensity for taking over the nest boxes intended for other birds is one of the main reasons why many people resent their presence.
These hardy little birds will not only move into the nest boxes intended for other birds, such as the eastern bluebird, purple martin, and tree swallow, they will evict the birds who have already established nests in those boxes, and they will go so far as to destroy existing eggs, kill the nestlings, or kill the females who are incubating the eggs!
On a much happier note, house sparrows play a beneficial role in controlling a wide variety of pests including caterpillars, aphids, moths, and ants, particularly during the spring and early summer. They mainly catch these insects to feed their offspring. House sparrows will also consume mollusks, crustaceans, earthworms, lizards, frogs, berries, fruits, nuts, and our discarded scraps of food! However, they much prefer grains and seeds, like corn, oats, wheat, and sorghum, which does not endear them to farmers!
Even though house sparrows threaten the existence of some of our native bird species and are capable of robbing farmers of their livelihood, these little birds are highly valued by a select group of biologists who are trying to learn more about the species. House sparrows are abundant, easy to raise, and generally don’t fear humans, which has made them an excellent model organism for many avian biological studies. To date, there have been nearly 5,000 scientific papers published using the house sparrow as the study species!
Prior to doing research for this article, I had no idea that house sparrows posed such a significant threat to our native bird populations, or posed a threat to some of our farmers. They were just sweet, little birds singing outside my window, who brought me joy and made dreary days feel like spring.
By Jeanne Church