Personalities and presence of hyperaggressive males influence male mating exclusivity and effective mating in stream water striders

Linking short-term behavior and personalities to feeding and mating rates in female water striders

“…At the broader level of population sex ratio, when the sex ratio was male-biased (and presumably there was more male harassment), females overall spent less time on the water, were less likely to start feeding, and were more likely to start mating, which are all consistent with general insights from previous studies in the genus Aquarius (Rowe et al 1994). At a more local scale, females were less likely to start mating if they were in the same pool as a hyper-aggressive male, which also agrees with recent work in this species (Chang and Sih 2013;Sih et al 2014;Wey et al 2015). Surprisingly, we found that the presence of a hyper-aggressive male did not reduce female feeding rates (but see Eldakar et al 2009).…”

“…Surprisingly, we found that the presence of a hyper-aggressive male did not reduce female feeding rates (but see Eldakar et al 2009). This outcome might be the result of an "enemy of my enemy can be my friend" effect where hyper-aggressive males reduce the activity of other males in pools (Chang & Sih 2013;Sih et al 2014;Wey et al 2015) and thus reduce harassment of females by those other males. This potential benefit to females is the focus of ongoing work.…”

“…Females also received a distinct color combination immediately posterior to their eyes, so that they could be identified during mating. The colors of a female's marking did not have an observable effect on her mating rate (Wey et al 2015). When not being used in the experiment, animals were held indoors in large, aerated holding tanks with refuges and abundant food.…”

“…Experiments were conducted in a shaded, outdoor artificial stream system, which has been previously used for studying water striders (Sih and Krupa 1995;Sih and Watters 2005;Chang and Sih 2013;Wey et al 2015). Briefly, the system included 4 linear streams, each consisting of 5 large (1.5-m diameter) circular pools, filled to a depth of ~40 cm, interconnected by narrow (137 cm × 37 cm) fiberglass troughs, which we refer to as "riffles," and fed by well water.…”

“…However, some males temporarily become unusually aggressive (hyper-aggressive) toward other individuals and even pairs. Hyper-aggression can only be observed on short timescales, but it can have important impacts on female feeding and mating (Sih and Watters 2005;Eldakar et al 2009;Chang and Sih 2013;Sih et al 2014;Wey et al 2015). Previous work suggests that hyperaggressive males might harass females irrespective of mating status and thus might have negative impacts on female feeding (Eldakar et al 2009).…”