Eurasian Tree Sparrow

Family: 
Passeridae (Old World sparrows) in the order Passeriformes
Description: 

This species is similar to the house sparrow and may be missed when it appears in mixed flocks. Adult upperparts are reddish brown with a chocolate brown head. The eye line is black, and the cheek is white with a black spot in the center. Underparts are grayish, with a brownish wash on the sides and flanks. The black bib is much smaller than on the house sparrow. Song is higher pitched than the house sparrow's and is more metallic. Call is a hard "tik tik" given in flight, or a "chit-chup."

Size: 
Length: 6 inches (tip of bill to tip of tail).
Habitat and conservation: 
Like its cousin, the house sparrow, the Eurasian tree sparrow of the St. Louis area is not a true American sparrow; rather, both are Old World sparrows that are more closely related to species in Europe, Asia and Africa. To the delight of nostalgic immigrants, the pair were introduced to America in the 1800s in hopes they would help control insect pests. Neither feeds much on insects, however, and the house sparrow, especially, has become a pest.
Foods: 
Seeds, grains, fruits, insects and bread crumbs.
Distribution in Missouri: 
St. Louis vicinity only. Throughout all of North America, this introduced species is only present in the St. Louis area and in nearby areas in Illinois and southeastern Iowa.
Status: 
Non-native. Common permanent resident (introduced).
Human connections: 
These introduced birds were greeted first with joy, then with disappointment as they failed to gobble up insects. As they multiplied and feasted on grains, they became a frustration. Yet avid birders travel to St. Louis for a chance to add this species to their "life lists."
Ecosystem connections: 
This species was introduced in St. Louis in 1870. Its population was doing well until house sparrows (introduced in New York in 1851) arrived in the area. The more aggressive, larger house sparrow settled in downtown St. Louis and the Eurasian tree sparrow became more residential or rural.