Compared to its close relative the Tree Swallow, little is known about the ecology and breeding biology of the Violet-green Swallow. From the handful of studies done on just a few populations, it appears that Violet-green Swallows are ecologically similar to Tree Swallows. Many questions, however, remain to be answered. Little is known about the mating system, territorial behavior, and juvenile dispersal of these swallows. Physical Description Violet-green Swallows are similar in appearance to Tree Swallows.
Males have nonglossy, velvety green or greenish bronze upperparts, and they are white underneath.
Unlike Tree Swallows, however, the white on the face of the Violet-green Swallow extends above the eyes. Also, the Violet-green has two white patches on its rump. Compared to the males, female Violet-green Swallows are dull in color. They are bronze green to bronze purple on the upperparts, and grayish on the forehead, the sides of the head, and the upper breast. The rump and tail feathers are a dull green.