The Eurasian Tree Sparrow

By Jim Jackson | May 2, 2003
From Missouri Conservationist: May 2003

A lady stopped me at the August A. Busch Conservation Area, a favorite St. Louis birding spot. With a smile, but seemingly in a hurry, she asked, "Could I find a Eurasian tree sparrow in this area?"

"I'm sorry, madam, it's not found here. But if you have a map of the St. Louis area, I'd be glad to point out some likely locations."

With this her smile suddenly faded. "Darn it, I wanted to get it on my life list, but a map won't help now. I've got to fly out of Lambert in two hours."

List-keeping birders can be as zealous as sportsmen who pursue their furred, feathered or finny game. In any field of outdoors recreation, participants are eager to meet new challenges. Birders find it particularly challenging to identify and list species found only in certain regions. The Eurasian tree sparrow is a unique example of such a species.

Its presence in Missouri dates back to shortly after the Civil War. At that time it was a fad among nature enthusiasts to import nightingales, chaffinches, bullfinches and other songbirds from Europe. This was done in the false hope that new birds might help control insect pests, but was also an excuse among nostalgic immigrants who wanted to see birds "from the old country." Most of these introductions failed, but a few, including the pesky starling, brought to Americain 1890, succeeded.

This article focuses on the relationship between two earlier introductions of Old World finches. One was the now ubiquitous house or English sparrow. The other was its closest relative, the Eurasian tree sparrow. Carl Daenzer imported some of the latter from Germany and released them in Lafayette Park, St Louis, on April 25th, 1870. At that time, house sparrows, which were initially released in New York City, were already spreading westward and into St. Louis.

Otto Widmann, a pharmacist who was also Missouri's earliest birder, followed the St. Louis area spread of both species through the late 1800s. In 1909, he wrote the following about what were then known as European tree sparrows. "But in the meantime their larger cousins, the House Sparrows, which made their original start from the center of town and had become more and more abundant, began to invade the domain of the European Tree Sparrows, driving them out of their nesting and roosting places, thereby forcing them farther and farther toward the outskirts of the city."

Today, after 130 years, Eurasian tree sparrows still cannot compete successfully with their larger cousins. Their relationship is like the gentle country cousins versus the aggressive street urchins. In this case, we know the latter as house sparrows, alias chippies.

Our much cherished St. Louis bird has never extended its range beyond about 150 miles from the city. The farthest from St. Louis the Eurasian tree sparrow has been found is along the Iowa border.

It's also curious that its range has extended northward, skirting the Mississippi River both in Illinois and in Missouri. It has not extended southward or westward.

Some speculate that the species has been forced northward by competition from house sparrows, but more likely differences in the natural habitats skirting the Mississippi south of St. Louis from those upstream from its confluence with the Missouri River explain why the bird's range seemed to be squeezed toward the north.

Eurasian tree sparrows--not to be confused with American tree sparrows that nest in the far north and visit Missouri only in winter--are readily identified by black dots showing on white checks. They also have a brownish crown and a small black throat patch. Unlike house sparrows, the sexes have identical plumage.

Both of the Old World finches are non-migratory, and both have similar nesting habits. They build rather bulky nests in crotches of trees, in tree cavities, under eaves of buildings and in bird boxes.

Ted R. Anderson, a research ornithologist at McKendree College in Lebanon, Illinois, once compared their uses of bird boxes in rural St. Charles County, where Eurasian tree sparrows were having difficulty competing against their city cousins. He made bird boxes with holes 1-1/4 inches in diameter, big enough for house sparrows, and others with holes 1-1/8 inches in diameter, barely big enough for the slightly smaller Eurasian tree sparrows.

He also noted that, while both species averaged 2.5 broods per year, Eurasian tree sparrows hatched three eggs to every two produced by their rivals. Anderson found that by regulating the size of bird boxes over several years, he increased the ratio of Eurasian tree sparrows to house sparrows at the St. Charles County study location.

During the non-nesting winter season, both of the Old World finch species frequently gather in roosts numbering upwards of 100. The Eurasian tree sparrows typically confine themselves to rural areas, while the house sparrows gather in large and noisy congregations around city buildings, where they are considered nuisances.

It's seems odd that house sparrows could become so prevalent nationwide while Eurasian tree sparrows remain confined to the greater St. Louis area. Anderson, who studies both species, said that the Eurasian tree sparrow initially ranged mostly in Asia while the house sparrow ranged primarily in Europe, but even longer ago might have belonged to the same species. After they became isolated, one strain, house sparrows, evolved to become aggressive, while the Eurasian tree sparrows became meek.

No records indicate whether Eurasian tree sparrows have ever been released elsewhere in America. Most people in Missouri hope not. They like the celebrity status the species gives to St. Louis. The birds may not garner as much attention as the St. Louis Cardinals, the Rams, the Arch or Shaw's Garden, but they do attract avid birders from all over the United States.

For example, in May 1972, Dick Anderson, an expert St. Louis birder, received a phone call from the Pentagon at his place of work. The caller explained that James Schlesinger, President Carter's Secretary of Defense, and an avid birder, was in town on official business. They asked if Anderson, after work, might find a Eurasian tree sparrow for the Secretary to add to his life list.

Anderson agreed, of course, and met Schlesinger, who flew in by helicopter, at a high school football field. The two shook hands and were chauffeured to a known Eurasian tree sparrow haunt. He and Schlesinger not only saw a Eurasian tree sparrow, but they lingered to watch the May migration of warblers. At dusk, before they parted company, Anderson asked the Secretary how often he was able to get out birding. Schlesinger answered, "Not often, but it does help maintain my sanity when I do."

Locating Eurasian tree sparrows

Within St. Louis, Eurasian tree sparrows are common in residential neighborhoods southwest of Forest Park. I saw them there as a teenager many years ago, and they continue to nest in the same neighborhood.

Public areas often provide better possibilities for watching Eurasian tree sparrows. Good viewing sites include the Corps of Engineers Riverlands Environmental Demonstration Area (Lock and Dam 26), North County Park, south of the I-270 bridge over the Mississippi River, at Winfield (Lock and Dam 25) and at Clarence Cannon National Wildlife Refuge, just north of Annana.

The Eurasian tree sparrow can also be found in scattered localities about the eastern, or floodplain, portion of St. Charles County and in numerous areas on the Illinois side of the Mississippi River.

This Issue's Staff

Editor - Tom Cwynar
Managing Editor - Bryan Hendricks
Art Editor - Dickson Stauffer
Designer - Les Fortenberry
Artist - Dave Besenger
Artist - Mark Raithel
Photographer - Jim Rathert
Photographer - Cliff White
Staff Writer - Jim Low
Staff Writer - Joan McKee
Circulation - Laura Scheuler