Display rate, territory holding status, body size and age in dark-winged damselflies (Calopteryx maculata).

Abstract

Dark-winged damselflies (Calopteryx maculata) display by opening and closing their wings as a courtship behavior to attract females. We hypothesize that non-territorial males will display at higher rates than territorial males because they sneak into other males' territories and they are discovered and subsequently chased out whereas territorial males can sit in their territory all day, displaying when they chose to. An alternate hypothesis is that males with higher body mass indices or longer abdomen lengths will display more because they have better genes than will attract more females. Their genes are better because they are able to be larger and display more while still avoiding higher rates of predation that should result from increased display. We observed C. maculata on the Maple River from late June through late July. We recorded total number of displays, time in territory, and location of territory, locality, and male category. We found no significant difference between display rates of different types of males, display rates between different BMI's of males or display rates between males of different abdomen lengths. We categorized male type by 1=local, territorial, 2=local, non-territorial, and 3=non-local, non-territorial. We found no difference in display rates of males of different ages either. All C. maculata males display at the same rates in an attempt to attract females and increase reproductive success.