This is bird note.

The house Barrow, introduced to North America from Europe in the mid 1800s

has spread across the continent and can be seen

grabbing French fries off the sidewalk

from coast to coast.

They often compete with native species

for nesting sites. In the 1870s another European

Sparrow came to the US but had a completely different fate.

In Lafayette Park in St. Louis, Missouri, a dozen or so Eurasian tree

sparrows from Germany were released. Their descendants fanned out across the city and its suburbs.

Eventually, some moved up the Mississippi River to Illinois and southeastern Iowa.

But that's about as far as they traveled.

Unlike house sparrows, Eurasian tree sparrows haven't become invasive in North America.

It's not fully clear why, but it's possible that they just behave differently, and the aggressive house sparrow may have helped prevent the tree sparrows from spreading further

by competing for the same nesting sites.

Eurasian tree sparrows still remain in a small area of the Midwest,

where they're not much of a nuisance to native birds

and are a local curiosity for birders.

For Bird Note, I'm Ariana Remmel.

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