Ravenox has a wide variety of traps to catch unwanted House Sparrows and European Starlings - both of which are invasive species.
There are two species of non-native birds, the European Starling and the House Sparrow, which will nest in Purple Martin housing. Both species were brought over from Europe and should never be permitted to nest in martin housing. They will take over martin compartments, destroy eggs, and kill nestlings. They can also prevent martins from nesting and often injure or kill adults. House Sparrows and European Starlings are not protected and may be legally controlled by trapping.
Starlings are larger than Purple Martins, with a stocky body, short tail, and a long yellow beak. Juvenile starlings may have a black beak. They have an iridescent purple-green-black coloring. Their winter plumage is brownish with white spots. They are seed eaters and are oftentimes found on the ground below feeders.
There are many different breeds of sparrows—only the House Sparrows are non-native. Other native sparrows such as the Song Sparrow and White-Crowned Sparrows will not be interested in nesting in your Purple Martin housing.