Interplay of male traits, male mating strategies and female mate choice in the Asian elephant, Elephas maximus

Behaviour ◽  
2015 ◽  
Vol 152 (7-8) ◽  
pp. 1113-1144 ◽  
Author(s):  
Karpagam Chelliah ◽  
Raman Sukumar

Elaborate male traits with no apparent adaptive value may have evolved through female mate discrimination. Tusks are an elaborate male-only trait in the Asian elephant that could potentially influence female mate choice. We examined the effect of male body size, tusk possession and musth status on female mate choice in an Asian elephant population. Large/musth males received positive responses from oestrous females towards courtship significantly more often than did small/non-musth males. Young, tusked non-musth males attempted courtship significantly more often than their tuskless peers, and received more positive responses (though statistically insignificant) than did tuskless males. A positive response did not necessarily translate into mating because of mate-guarding by a dominant male. Female elephants appear to choose mates based primarily on traits such as musth that signal direct fertility benefits through increased sperm received than for traits such as tusks that may signal only indirect fitness benefits.

Parasitology ◽  
2004 ◽  
Vol 129 (6) ◽  
pp. 723-731 ◽  
Author(s):  
K. D. EHMAN ◽  
M. E. SCOTT

Considering that both infection and dominance status can be conveyed through urinary odours and both are thought to affect mate choice, the present study assessed the role of infection and male dominance status on female mate choice in arena enclosures. Three male CD-1 mice were simultaneously introduced into each of 4 spatially complex arenas (3·0×0·6×0·4 m high) for 24 h prior to introduction of 5 females into each arena. During the first mating sequence (i.e. Mating 1), all 3 males were uninfected. Prior to Mating 2, the dominant male in each arena was infected with 200 L3 of Heligmosomoides polygyrus (Nematoda). Prior to Mating 3, the dominant male was drug-treated to remove the parasite. Dominance was assessed by the absence of rump or tail wounds (Freeland, 1981). Females were removed from the arena when visibly pregnant, and returned for subsequent mating 2 weeks following parturition. Paternity was determined by microsatellite analysis of each pup. Multi-male mating (i.e. mating with 2 or all 3 males) was a common strategy among females as littermates were sired by 2 or all 3 males in 64% of the litters. Contrary to expectation, the dominant male did not sire the majority of offspring in any of the mating sequences, and infection and subsequent drug treatment of the dominant male did not have a significant impact on female mate choice. In addition to methodological differences in paternity determination (i.e. DNA analysis versus behavioural observations and/or phenotypic traits), these findings may be further explained by the spatial complexity of the experimental arenas.


Behaviour ◽  
1995 ◽  
Vol 132 (11-12) ◽  
pp. 821-836 ◽  
Author(s):  
Torgeir S. Johnsen ◽  
Stacey L. Popma ◽  
Marlene Zuk

AbstractWe studied the role of male courtship behaviour in female mate choice in red jungle fowl (Gallus gallus), the ancestor of domestic chickens. The traits most highly correlated with behavioural displays were those most relied upon by females in making mate choice decisions. These traits (comb length, comb colour, eye colour, and spur length) are highly condition-dependent in jungle fowl. Females chose males that displayed at a greater overall intensity in the period after the female was allowed to interact with the males (post-release), but were indifferent to displays during the period before the female could approach the roosters (pre-release). After accounting for the effect of morphology on mate choice, waltzes were the only display that explained a significant amount of variation in male mating success. Chosen and rejected males had different display rates even when the female was not present. Plasma testosterone level was correlated with pre-release behaviours, but not with post-release behaviours or mating success.


2006 ◽  
Vol 361 (1466) ◽  
pp. 319-334 ◽  
Author(s):  
Hanna Kokko ◽  
Daniel J Rankin

Two very basic ideas in sexual selection are heavily influenced by numbers of potential mates: the evolution of anisogamy, leading to sex role differentiation, and the frequency dependence of reproductive success that tends to equalize primary sex ratios. However, being explicit about the numbers of potential mates is not typical to most evolutionary theory of sexual selection. Here, we argue that this may prevent us from finding the appropriate ecological equilibria that determine the evolutionary endpoints of selection. We review both theoretical and empirical advances on how population density may influence aspects of mating systems such as intrasexual competition, female choice or resistance, and parental care. Density can have strong effects on selective pressures, whether or not there is phenotypic plasticity in individual strategies with respect to density. Mating skew may either increase or decrease with density, which may be aided or counteracted by changes in female behaviour. Switchpoints between alternative mating strategies can be density dependent, and mate encounter rates may influence mate choice (including mutual mate choice), multiple mating, female resistance to male mating attempts, mate searching, mate guarding, parental care, and the probability of divorce. Considering density-dependent selection may be essential for understanding how populations can persist at all despite sexual conflict, but simple models seem to fail to predict the diversity of observed responses in nature. This highlights the importance of considering the interaction between mating systems and population dynamics, and we strongly encourage further work in this area.


2020 ◽  
pp. 305-331
Author(s):  
Rickey Cothran

Research using crustaceans has improved the understanding of sexual selection and sexual conflict. This is particularly true for understanding the biology of male weaponry and sexual conflict over mate guarding. Male crustaceans often are equipped with exaggerated claws that they use to monopolize access to females or resources that females use for reproduction. However, these weapons are often used in other contexts, e.g. mate choice and coercion of females, and understanding their evolution requires a broader perspective of how these traits are built and the fitness consequences of their use for both the bearer and interacting individuals. Although less well studied than male weaponry, crustaceans also provide excellent examples of elaborate sensory structures that are used in scramble competition among males for females. In addition to studies on male-male competition, crustaceans have been well represented in research on intrasexual selection (for the most part, female mate choice). Crustacean females use a variety of sensory channels to assess mates, and a challenge is to better understand what is being conveyed by signaling males and the fitness consequences of mate choice for females. In some cases the female’s sensory system appears to be exploited by males, and this could lead to sexual conflict over mating. Research on crustaceans has also informed the understanding of sexual conflict over mate guarding, including the evolution of traits used to resolve conflict and how the ecological context shapes the costs and benefits of guarding for both sexes.


Ethology ◽  
2015 ◽  
Vol 121 (11) ◽  
pp. 1091-1103 ◽  
Author(s):  
Valentina Scarponi ◽  
Deepro Chowdhury ◽  
Jean-Guy J. Godin

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