Northern Prairie Wildlife Research Center
Red-tailed Tropicbirds are white with two long, thin red tailfeathers. The bill is bright red, and the eyes are lined with black. Immature birds have black barring over the back and upper wing surfaces. They are tolerant of human activity but susceptible to cat, dog, and rat predation. Several thousand red-tailed tropicbirds use Johnston Island, with current increased populations probably resulting from the increased amount of vegetation.