From Tolkien Gateway

Starlings was one of the many species of birds found in Middle-earth. After Smaug's death many birds were gathering around Erebor. Thorin saw among them "starlings and flocks of finches".[1]

Tom Bombadil mentions starlings in his song Hey dol! merry dol! ring a dong dillo! in the Old Forest: "Light goes the weather-wind and the feathered starling."[2] He himself is compared to a starling when he enters the room in his house where the hobbits had been sleeping: "Tom was moving about the room whistling like a starling."[3]