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In general, males of a species expend a lot of energy attracting females. There are many instances where males utilize much of their nutrient intake to produce antlers, tusks, horns, etc. to either attract females or compete with other males for potential mates. Are their any instances in animals in which the females do this to attract males or to compete with other females? If so, what features have the females evolved to win over potential mates and fight off competitors and what advantage is there for the species?

I'm aware of a few animals, such as the seahorse and jacana where the males invest more energy in the offspring, but I'm not sure that the females of these species expend some of the energy saved in the offpring and put it into attracting males or competition with other females.

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    $\begingroup$ On the risk of being hilarious? Humans. $\endgroup$ – skymningen Dec 11 '17 at 12:51
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    $\begingroup$ One thing to consider here is the definition of female. Females are not defined by their genitalia, but rather, the size of their gametes. The animal with the larger gametes is the female. As such, her gametes are more valuable as a resource. Sperm are cheap and expendable. Eggs are precious resources. So this explains the difference. I kind of agree with skymningen's comment about humans. Human females DO spend more effort to attract mates. But they are more selective than their suitors, while men spend more time "seeking" $\endgroup$ – Karl Kjer Dec 11 '17 at 16:35
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The reason why, in most species, males are competing to access females and females are choosy is due to Bateman's principle.

Bateman suggested that, since males are capable of producing millions of sperm cells with little effort, while females invest much higher levels of energy in order to nurture a relatively small number of eggs, the female plays a significantly larger role in their offspring's reproductive success. Bateman’s paradigm thus views females as the limiting factor of parental investment, over which males will compete in order to copulate successfully.

But there are exceptions to this general rule.

Fish

In many fish species (e.g. pipefish, scissortail sergeant and seahorses), males are choosy and females are competing. In these species, females deposit their eggs in a special brooding pouch that the male possesses. The male then has the energy cost of raising the offspring, while the female does not provide any parental care. As a result, males in these species must choose among competiting females for mates( Vincent et al., 1992)

Birds

In many bird species, there is bi-parental care, leading to competition among mates in both species. See the interesting case of Jacana jacana (Emlen and Wrege, 2004).

Frogs

In poison-arrow frogs (Dendrobates auratus), the male spend more energy for raising the offspring than the females and the males are therefore choosy (Wells, 1978).


Related: Why are female not competitive for reproduction like males?

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  • $\begingroup$ I'm looking at this as a total energy used by both sexes and am interested in how the female utilizes the saved energy when the male is using more of the total on the offspring. So, if I'm reading the article correctly for the Jacana jacana, it appears that the females have greater development of fleshy facial ornamentation (attraction) and wing spurs (for competition) in exchange for the energy saved from raising offspring? $\endgroup$ – wanderweeer Dec 12 '17 at 0:08

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