An ecological classification of odonate mating systems: the relative influence of natural, inter- and intra-sexual selection on males

Abstract

We separate the mating systems of odonates into two main groups: non-resource and resource-based systems. These two groups comprise five classes of mating system: encounter-limited mating, free female choice, resource-limitation, resource-control and female-control. These classes are consistent with previous classifications of odonate mating systems and with the overall classification of mating systems by Emlen & Oring (1977: Science, 197: 215-223). Whereas Emlen & Oring's classification of mating systems was concerned with differences in sexual selection between mating systems, our classification of odonate mating systems also addresses the influence of inter-and intra-sexual selection on males within a mating system. Predictions about such relationships are useful in multivariate analysis of odonate lifetime reproduction success. Among most odonate mating systems, much of the sexual selection on males results from male-male competition for access to mates. Sexual selection via female choice is relatively less important or operates indirectly through females' choices of times or places to mate. We place resource-control and resource-limitation at opposite ends of a resource-defence continuum and postulate female choice will have greater influence in mating systems that are more like a resource-limitation system and less influence in mating systems that are more like resource-control. Sexual selection is likely to be weak in species that resort to encounter-limited mating where longevity is likely to contribute strongly to variation in reproductive success. Females have limited opportunity to exercise choice among males in the female-control mating system and in this system selection is most likely to operate on male characters which contribute to their efficiency in searching for and capturing mates. Predictions about the differences in the intensity of sexual selection between different odonate mating systems should be made on the basis of the variation in the number of potential fertilizations per male or even per ejaculate, rather than the number of fertilizable females per male. Very different mating systems could result in similar patterns of variation in male reproductive success.

Cues for territory choice in two tropical dragonflies

“…However, detailed studies have determined a more complex picture that classify their mating systems into: i) non-resource-based systems, subdivided into free female choice, female-control, and encounter-limited systems and ii) resource-based systems; subdivided into resource-control and resource-limitation systems (Conrad & Pritchard 1992, Battin 1993. As part of their classification, Conrad & Pritchard (1992) used the way that odonate males control female access to oviposition sites. For example, if oviposition sites are clumped it is economically possible to fight for control of female access to these sites (Sherman 1983, Buskirk & Sherman 1985, Alcock 1987.…”

Behavioral ecology of Heteragrion consors Hagen (Odonata, Megapodagrionidae): a shade-seek Atlantic forest damselfly

“…This also diminished the harassment of mated females by other males and could be advantageous to the females (Waage 1979a;Conrad & Pritchard 1990). Emlen & Oring (1977) pointed out that receptive female availability and possibility of resource defense by males are key factors in mating system evolution, and this was also emphasized particularly in Odonata (Conrad & Pritchard 1992). The mating systems showed by H. consors is not based purely on active search for females, but on waiting for mating opportunities by males that cannot control oviposition resources.…”

“…The mating systems showed by H. consors is not based purely on active search for females, but on waiting for mating opportunities by males that cannot control oviposition resources. According to the Conrad & Pritchard (1992) classification, H. consors fits to a non-resource system. Co-occurence between potential sexual partners in time and space in H. consors and the absence of courtship displays contribute to the maintenance of males with the ability to defend areas with better chance to intercept females.…”

“…The last option was possibly rare due to the negative effects of male harassment in these circumstances. It is expected that when the male physically keeps the female from other males, the oviposition sites are numerous and dispersed, males are weak fliers and female encounter is rare, Odonata males are not able to perform resource control strategies (Conrad & Pritchard 1988;Conrad & Pritchard 1992). H. consors mating system clearly fits to this classification.…”

“…In this context, territorial defense could also enhance the female opportunity to choose among males with different "qualities", usually measured by its ability to maintain a territorial site (Alcock 1979;Fincke 1997). In this system, known as resource-control system (Conrad & Pritchard 1992), the males defend aggregated oviposition sites and individuals that had morphological or behavioral traits that increase its success in territory acquisition will be favored by sexual selection. In a resource-limitation system, oviposition resources are identifiable in the habitat but it is economically impossible to control its access to the females.…”