Two species of wild birds that thrive in North America—and have been since the 19th century—are not even native: the European starling and the house sparrow.
Two species of wild birds that thrive in North America—and have been since the 19th century—are not even native: the European starling and the house sparrow. The fact that only a handful of these birds were captured and shipped to this continent from anoth- er continent far across the Atlantic Ocean and quickly spread nearly everywhere is testament to not only the astonishing adaptability of the birds, but underscore the consequences of introducing non-native species of organ- isms to distant landscapes.
The pervasive house spar- row, also called English spar- row, which is really a species of finch, has learned to exploit human-made dwellings and the
with our activities
for their survival.
This applies to
both farm spar-
rows and city sparrows—each of
which takes full
advantage of what
food, water, shelter, and space is available within these respective environ- ments.
Nesting in every imagina- ble structural crevice, be it cracks and holes in masonry and siding, under the eaves of buildings, inside bird houses, within dense shrub- bery, and the like, it’s no wonder that the resourceful house sparrow is as success- ful and reproductively pro- lific as it is. What with few natural enemies sharing their urban environments,
along with an abundance of habitat and food, not to mention their ability to with- stand Minnesota’s winter months, house sparrows are hardy birds.
Wherever house sparrows occur in their non-native, adopted homeland—which includes southern Africa, eastern Australia, Canada, 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 pre- vent house sparrows from becoming established there.
While it is true that the aggressive house sparrow is
known to evict native birds from artificial nest boxes and, sometimes, for instance, even killing adult blue- birds, bluebird nestlings, and destroying blue- bird eggs in order
to occupy the nest cavities for themselves, recent popu- lation trends from Breeding Bird Survey data suggests slight population declines, particularly rural house sparrow populations.
The reason for this decline follows the general reduc- tion of small farms and live- stock. Additionally, the widespread use of pesticides and overall increase in farm- ing efficacy (less grain waste, less weed seeds, no-till farm- ing practices, etc.), are also thought to be factors that
negatively impact house sparrows and house sparrow populations.
Nonetheless, from approximately 50 pairs of house sparrows released into the United States in the mid- 1800s, house sparrows repro- duced, expanded their range, and quickly estab- lished themselves as one of the most abundant species of birds in North America.
And by the 1940s the house sparrow population was esti- mated at 150 million individ- ual birds.
Equally as prolific and adaptable is another non- native species of bird to con- sider: the European starling. Estimated at over 200 mil- lion individuals in North America alone, the starling began its march across the continent from just one hun- dred 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 27 years, starling observations have increased by well over 300 percent. From Florida to Alaska and all places in between, star- lings can be found nearly everywhere today.
Even though starlings resemble blackbirds, they are not related. Blackbirds and starlings each belong to dif- ferent families. A medium- sized bird of about 81⁄2 inch- es long with a short tail and pointed triangular wings, when in flight an observer might wonder if the birds were meadowlarks or
waxwings instead—their flight pattern is quite similar to the latter species. But most similarities stop there.
Like house sparrows, star- lings are well known for their close association with human dwellings and other- wise human-altered habitats. They frequently are observed feeding and roost- ing in large flocks on farm- steads and urban centers alike. Vocalizations are not especially loud, but unusual and varied. Variable whis- tles, rattles, hisses, gurgles, chatters, and other noises are blended together to produce very curious and uncommon sounds.
Close inspection of the breeding plumage of star- lings reveals a rather colorful arrangement, albeit difficult to distinguish from a dis- tance. Iridescent feathers show off purples, greens, and blacks with some white speckling and a bright yel- low bill. Yet in spite of sev- eral unique features, a behavioral quality makes the starling a not-so-desirable species of bird to not only people, but to such birds as bluebirds and woodpeckers.
Similar to house spar- rows, European starlings are notorious cavity competitors. As a cavity nester not fussy about where and what kind of cavity they nest in, star- lings will often displace native birds from artificial bird houses and natural tree cavities or woodpecker holes.
The fact that house spar- rows and European starlings were introduced to North
America and subsequently flourished is the direct result of human meddling. Even so, all of us can agree that the two species of birds are survivors and are here to
stay, like them or not, as we get out and enjoy the great outdoors.
Blane loves to hear from readers. Email him at bkle- firstname.lastname@example.org.