It is uncommon to see the broad-winged skimmers from the genus Tramea perching. Dragonflies are classified as either “fliers” or “perchers,” based upon their feeding habits. Black Saddlebags are fliers.
Black Saddlebags is one of at least five major species of dragonflies known to be migratory in North America. Broad hindwings is an adaptation that enables Black Saddlebags to glide easily when flying. Dragonflies expend less energy when gliding, an aide to long-distance migration. According to the axiom in biology/morphology, form follows function.
Slaty Skimmer dragonflies (Libellula incesta), such as the mature male shown below, look somewhat similar to Black Saddlebags. Slaty Skimmers are “perchers.” Slaty Skimmers aren’t migratory; notice their hindwings are narrower than Black Saddlebags.
Related Resource: A sampler of male dragonfly claspers (Part 2). (See “Skimmer Family,” Black Saddlebags dragonfly.)
Copyright © 2015 Walter Sanford. All rights reserved.
Tags: Black Saddlebags dragonfly, Huntley Meadows Park, Libellula incesta, male, mature male, migratory, Skimmer Family, Slaty Skimmer dragonfly, terminal appendages, Tramea lacerata, wildlife photography