It's no secret to most people that house sparrows, sometimes called English sparrows, are a non-native species of bird originally from Europe. House sparrows have thrived in North America ever since their 19th-century release into several American cities. Today, house sparrows can be found from coast to coast in nearly every conceivable environment, both urban and rural.
The adaptable house sparrow, which is really a species of finch, has learned to exploit human-made dwellings, and the food associated with our activities, for their survival. This applies to both farm sparrows and city sparrows -- both of which take full advantage of what food, water, shelter and space are available within these respective environments.
Nesting in every imaginable structural crevice, be it cracks and holes in masonry and siding, under the eaves of buildings, inside bird houses or within dense shrubbery, it's no wonder that the resourceful house sparrow is as successful and reproductively prolific as it is. With few natural enemies sharing their urban environments, along with an abundance of habitat and food, not to mention their ability to withstand Minnesota's winter months, house sparrows, like them or not, are hardy birds.
Wherever house sparrows occur in their non-native, adopted homeland -- which comprises southern Africa, eastern Australia, Canada, the United States, Mexico, Central America and South America -- they are widely considered a pest. So much so that, for example, the bird is largely absent from the western half of Australia because of persistent control programs that work to prevent house sparrows from becoming established there.
In the United States, the house sparrow is one of only three species of birds that are not protected by law and can therefore be killed anytime. The other two species (non-natives as well) are the European starling, which we'll visit in a moment, and the rock pigeon.
It's true that the aggressive house sparrow is known to evict native birds from artificial nest boxes and, sometimes even killing adult bluebirds and bluebird nestlings and destroying bluebird eggs in order to occupy the nest cavities for themselves. However, recent population trends from Breeding Bird Survey data suggests slight population declines, particularly in rural house sparrow populations.
The reason for this decline follows the general reduction of small farms and livestock. Additionally, the widespread use of pesticides and overall increase in farming efficacy (less grain waste, less weed seeds, no-till farming practices, etc.), are also thought to be factors that negatively impact house sparrows and house sparrow populations.
Even so, from approximately 50 pair of house sparrows released into the United States in the mid-1800s, house sparrows reproduced, expanded their range and quickly established themselves as one of the most abundant species of birds in North America. And by the 1940s, the house sparrow population was estimated at 150 million individual birds.
As such, and equally as prolific and adaptable, is another non-native species of bird to consider: the European starling. Estimated at more than 200 million in North America alone, the starlings began their march across the continent from just 100 birds that were released into New York City's Central Park in the late 1890s.
In fact, in checking Alaska's National Audubon Society's Christmas Bird Count's starling records over the past 20 years, starling observations have increased by more than 320 percent from 1990 to 2010. From Florida to Alaska and all places in between, starlings can be found nearly everywhere today.
Even though starlings resemble blackbirds, they are not related. Blackbirds and starlings each belong to different families. A medium-sized bird of about 8½ inches long with a short tail and pointed triangular wings, when in flight an observer might wonder if the starling was a meadowlark or waxwing instead -- the flight pattern is quite similar to the latter species. But most similarities stop there.
Like house sparrows, starlings are well known for their close association with human dwellings and otherwise human-altered habitats. They frequently are observed feeding and roosting in large flocks on farmsteads and urban centers alike. Vocalizations are not especially loud, but are unusual and varied. Variable whistles, rattles, hisses, gurgles, chatters and other noises are blended together to produce very curious and uncommon sounds.
Close inspection of the breeding plumage of starlings reveals a rather colorful arrangement, albeit difficult to distinguish from a distance. Iridescent feathers show off purples, greens and blacks with some white speckling and a bright yellow bill. Yet in spite of several unique features, a behavioral quality makes the starling a not-so-desirable species of bird to not only people, but such birds as bluebirds and woodpeckers.
Similar to house sparrows, European starlings are notorious cavity competitors. As a cavity nester not fussy about where and what kind of cavity they nest in, starlings will often displace native birds from artificial bird houses and natural tree cavities or woodpecker holes.
Regardless of how we view these two species, two facts cannot be disputed: They like it here in America and have decided to stay put. So the question could be posed -- at what point do we finally accept these avian immigrants as our own? Indeed, something to ponder as we get out and enjoy the great outdoors.
BLANE KLEMEK is a Minnesota DNR wildlife manager. He can be reached at email@example.com.