Successful Starlings

This non-native black bird has made itself right at home in North America.  

But between 1890 and 1891 he tried again with 100 European starlings, setting them free in New York City’s Central Park. From that humble beginning the starling became one of the most common birds in North America, numbering perhaps 200 million individual birds today. The question being asked now is whether the starling is a beneficial bird or a biological nightmare. It depends on whom you ask. And when.

In 1931 a U.S. Department of Agriculture bulletin praised the bird, stating, “The starling is one of the most effective bird enemies of terrestrial insect pests in this country.” For much of the year the starling does eat mostly insects, which make up more than half of its diet. Unfortunately, it also likes fruit and grain, and has become a serious pest in orchards and feedlots. And its roosting habits have turned some cities into armed camps as local governments try every method they can devise to exterminate the bird, or at least encourage it to nest in another location.

Actually, the starling is quite an interesting bird. Approximately the size of a robin, in spring the starling is the only black bird with a yellow bill. After its fall molt, the bird has feathers covered with white stars, giving it a speckled look, and its long, round bill is dark brown in color. But as the year progresses, the white wears off of the feathers, leaving the bird’s plumage an iridescent black with purple and green highlights. As the breeding season approaches, the bill turns a brilliant yellow.

The starling might be called handsome if it weren’t for its shape. Most blackbirds have long, elegant tails, but the starling’s tail is short and stubby. When it takes to the air, the lack of a balancing tail makes it look like a flying triangle. Other blackbirds gracefully swoop through the sky, while the starling streaks in a straight line. And when it lands, the starling walks where others hop. To put it bluntly, the starling waddles.

But it’s a truly efficient hunter of insects, particularly on the ground, where it spends much of its time. The starling’s jaw muscle is designed to work in the opposite direction from most other birds. Where normally a bird’s bill snaps shut when catching a flying insect, the starling’s muscle springs the bill open instead. If the bird inserts its closed bill between blades of grass or thick turf, the bill springs open to expose hidden prey. And as the bill opens, the bird’s eyes automatically shift forward, giving it better binocular vision to find a hidden meal.

Since starlings tend to feed in flocks, they have developed what is called a roller pattern of searching for food. The flock will gradually move across a field by playing leapfrog. The rearmost birds will fly over the group and then forage at the front. As this happens over and over again, each bird has an opportunity to be the “first” to explore new territory.

The starling’s flocking behavior isn’t limited to mealtime. Several hours before sunset, flocks of birds begin moving toward their evening roost. They follow regular routes, coming from all directions, and the final gathering can be immense. Sometimes the roost will be located in a city, which can lead to serious conflicts with the human inhabitants.

The size of the problem is well described by Herb Wilson, a professor of biology at Colby College in Maine: “I’ve seen flocks of more than 1,000 birds in Maine, but that pales in comparison to a roosting flock of starlings, common grackles, and brown-headed cowbirds in Kentucky that had over a million birds in an area of only five acres.” And some accounts report roosts that may be 10 times larger.

The masses of arriving birds create beautiful patterns in the air as they swirl and twist before diving into the trees where they will spend the night. The next morning they reverse the procedure, break up into smaller flocks, and disperse for the day’s work.

Starlings are great mimics, able to sound like many other critters. We once spent part of an afternoon in an Arizona campground trying to locate a cat we could hear nearby. It turned out to be a starling on a telephone wire above our motorhome.

Since starlings are a non-native species, they don’t have the protection of other birds, so some people choose to raise young starlings as pets. Of course, the birds soon pick up household sounds and try to imitate them. They can sound like cell phones and do a pretty good job learning human speech.

Turning starlings into pets is nothing new. Wolfgang Amadeus Mozart had a starling that he purchased from a pet store. It died after three years, and he gave it an elaborate funeral. Eight days later, Mozart composed his famous “A Musical Joke,” which puzzled listeners for years. Finally someone figured out that the off-key whistles that appear in the piece are probably tributes to his pet bird.

The success story of the starling is an example of what can happen when an exotic species is introduced into an environment that fits its needs. Explosive population growth that endangers many native species can occur. In this case, since the starling is a cavity nester, it competes with the many birds that also nest in small spaces. No one knows for sure what our avian world would be like if there were no starlings in North America.

But it’s not a one-sided picture. The starling is an extraordinary insect hunter and does help control some pest species. And it acts as a food source for birds such as the peregrine falcon. A study of falcon recovery efforts in the state of Washington found that starlings, since they are so numerous, were one of the main year-round prey items found in peregrine nests.

Lessons can be learned from Eugene Schieffelin’s experiment. In the complex world of nature, sometimes small changes produce bigger results than expected. The starling is here to stay, but perhaps that kind of experiment should not be tried again.