European Starlings were introduced to North America in 1890 and are known for taking over nesting sites of other birds. A study compared the populations of 27 native cavity-nesting bird species before and after starlings invaded their habitats. Surprisingly, only 10 species showed significant effects from starlings, and only half of these were negative. Sapsuckers were the only species that exhibited declines potentially caused by starlings that were not offset by other factors. Overall, native hole-nesting birds have managed to hold their own against the starling invasion, despite the aggressive competition for nesting sites.