European Starlings and House Sparrows

European
Starlings are powerful, aggressive, and abundant birds. They are about 8 inches
long with a powerful, dagger-like beak that can be used to kill Purple Martins.
If allowed to use your martin housing, they will ruin your chances of attracting
martins. The easiest way to identify a Starling is by the beak.
Starlings have a long, pointed, yellow beak, (Martins have a short, wide,
flat, black beak.) Starlings also have long legs, whereas martins have
short legs. Starlings were imported from Europe over a century ago, spread
rapidly, and have become a problem for all of our native cavity nesting species.
House
Sparrows are a small brownish bird about the size of our native sparrows.
They are actually not a sparrow at all, but a finch. They are aggressive
and persistent, and will ruin your chances of attracting martins if allowed to
use your martin housing. Like starlings, House Sparrows were imported from
Europe over a century ago and have become a problem for all of our native cavity
nesting species. The males have a black bib. The females lack this black
bib and are rather nondescript. No native sparrows will attempt to nest in
your martin housing because they are not cavity nesters.