Female aggression in red deer: Does it indicate competition for mates?

Abstract

Female-female competition over mates is often considered of minor importance, particularly in polygynous species. In red deer (Cervus elaphus), female-female aggression within harems during the breeding season has not been studied to date. Herein, we examined if oestrous female red deer in harems show elevated aggression rates, compared to when they are in harems but not in oestrous, and also when they are in foraging groups outside of the breeding season. Any increased levels of aggression involving oestrous females, could indicate the potential for female-female competition for mates in this species. We found that aggressive interactions among female red deer were clearly evident. The most common forms of aggression were displacements, nose threats and kicking. Biting and ear threats occurred less frequently, and chases were rare. There were no differences in the proportion of the different aggression types in the three social contexts. More importantly, we found that the highest overall rates of aggression were for oestrous females in harems, and for females in foraging groups. The lowest rates of aggression were found in harems (when the focal female was not in oestrous). If high rates of aggression also occur when several females are simultaneously in oestrous within single harems, then it is possible that this aggression could affect either mate choice or mating order. These results suggest that female-female competition over mates could play a role in the mating behaviour of red deer.

Sexual Selection in Males and Females

“…3). Similarly, in some polygynous ungulates where males initially compete intensely for females, females that have entered estrus and need to mate rapidly compete for the attentions of defending males (57,58). Several studies of species where both sexes make large investments in their offspring have shown that the relative intensity of reproductive competition in the two sexes can be changed by manipulating resource availability and reversing sex differences in PRR (59,60).…”

Female–female competition or male mate choice? Patterns of courtship and breeding behavior among feral horses (Equus caballus) on Assateague Island

“…Female competition over mating opportunities has been demonstrated in three other polygynous ungulates (red deer, Cervus elaphus, Bebié and McElligott 2006;topi, Damaliscus lunatus, Bro-Jørgensen 2002;saiga, Saiga tatarica tatarica, Milner-Gulland et al 2003). While females may be in competition for access to resources in a male's territory or home range, they may also be competing for the male's interest and limited sperm.…”

“…Overt aggression among females over mating opportunities has been observed in birds (Barnard and Markus 1989;Brown et al 1997;Nakamura 1998; reviewed by Slagsvold and Lifjeld 1994), amphibians (Bush and Dell 1997;Waights 1996), carnivores (Frame et al 1979;Rabb et al 1967;Rood 1980;Zimen 1975), ungulates (Bebié and McElligott 2006;Mackler and Dolan 1980), primates (reviewed by Niemeyer and Anderson 1983;Rendall and Taylor 1991), rodents (Bennett et al 1999), and fish (Brandtmann et al 1999). Competition for access to males may take the form of copulation harassment, or more subtly, females may restrict one another's access to the male by placing themselves close to him and displacing other females.…”

Intra- and Intersexual Conflicts and Cooperation in the Evolution of Mating Strategies: Lessons Learnt From Ungulates

“…This is supported by the fact that aggressive acts by oestrous topi females increase their probability of mating (Bro-Jørgensen 2007b). A similar basis for female mate competition may also explain increased female aggression on fallow deer leks (Schaal 1987) and in oestrous red deer hinds (Bebie and McElligott 2006). Perhaps the strongest evidence that mate limitation can drive female competition is provided by a study on the saiga antelope (Saiga tatarica) which found that dominants aggressively excluded subordinates from mating, but only after poaching had biased the adult sexratio heavily towards females (Milner-Gulland et al 2003).…”