Demographic Traits and Behavior of Hetaerina cruentata (Odonata: Calopterygidae) in Ecosystems of the Andean Region of Colombia

Abstract

Demography and territorial behavior of Hetaerina cruentata was studied along three lowland streams located at Norte de Santander department in the Colombian Andean region. Adult damselflies (N: 278) were individually marked, and using their recapture histories we estimated survival, longevity, sex ratio, age groups and population size at each location. We found no evidence for survival differences between ages and sexes. However, the proportion of resighted individuals was lower for females, and the sex ratio was male-biased in all populations. Although we recorded few reproductive events, a high number of male-male agonistic interactions were registered around midday. During reproductive behavior, we observed brief wing displays as signals between males and females, and the formation of the tandem position, followed by the intra-male sperm translocation and copulation (mean duration 11.3 min). After copulation, the pair in tandem looked for suitable sites to oviposit, and then the male broke tandem and perched on the vegetation while the female laid eggs partially or completely underwater. The recapture probability was time-dependent, which suggests that the alternation of rainy and sunny days during the study may be generating differences in the demography of the three H. cruentata populations.