Life Sciences Commons^™

The Role Of Landmarks In Territory Maintenance By The Black Saddlebags Dragonfly, Tramea Lacerata, Jeffrey Lojewski

Masters Theses

Territoriality can reduce competition for resources, but territorial defense can be costly. Therefore any behavior that reduces territorial costs may increase the net benefit of territoriality. Some species will align their territory boundaries with conspicuous landmarks that may serve to reduce defense costs. Dragonflies, including black saddlebags (Tramea lacerata), defend territories at breeding sites, keeping rival males away to allow themselves access to females. We used three treatments to investigate whether T. lacerata used landmarks: constraining landmarks (an object that provided a physical barrier to flight), non-constraining landmarks (an object of the same dimensions and construction that did …