Study species
Dragonflies and damselflies are considered as prime model systems for evolutionary and ecological research (Córdoba-Aguilar 2008). One of the most intensively studied families within Odonata isCalopterygidae (Córdoba-Aguilar, 2008). Calopteryx splendens is a very conspicuous representative from this damselfly family inhabiting lowland rivers in Europe (Askew, 1988; Dijkstra, 2006). C. splendens exhibits sexual dimorphism in body colouration, with blue reflecting dark wing spots in the middle of the wings of males, which is a trait easily recognizable from distance (Askew, 2004). Average life span of a mature male is ca. 1 week (Svensson et al., 2006; Svensson and Friberg, 2007; Tynkkynen et al., 2009) and the territorial and sexual behaviours of calopterygids, as well as traits determining C. splendens flight abilities, have been intensively studied over the past 20 years (Marden, 2008; Suhonen et al., 2008). Calopteryx sp. males defend territories (e.g. floating aquatic vegetation) and demonstrate a wide range of easily observed behaviours such as patrolling, aerial contests with conspecifics and courtship dances (Golab et al., 2017; Marden and Waage, 1990; Rüppell et al., 2005; Waage, 1973). The flying patterns of different behaviours are very specific and easy to observe with the naked eye from a distance of several meters (Corbet, 1999; Golab et al., 2017; Pajunen, 1966). The species easily habituates to the observer and after a disturbance in/of their environment, damselflies resume normal activity within minutes (Golab et al., 2017, 2013). The adult damselfly and its breeding sites are easily accessible to the investigator (Córdoba-Aguilar & Cordero-Rivera 2005) and breeding site features can be manipulated or highly controlled (Golab et al., 2017, 2013). Trapping and behavioural observations do not affect individuals’ behaviours (Golab et al., 2017, 2013) and methods of individual marking and field observations are well established and do not have overt effects on individuals (e.g. Golab et al., 2017; Kuitunen et al., 2010; Plaistow and Siva-Jothy, 1996). Adult C. splendens individuals have strong site fidelity and less than 15% of population disperse more than 150 m (Schutte et al., 1997; Stettmer, 1996).