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14 Cards in this Set

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  • Back
Explain why there is male competition.
Males can produce a large amount of sperm with a minimal investment of energy, they are always sexually receptive. Therefore, the goal of every male is to fertilize as many females as possible. There is little difference between the instinctive drive of a sperm to reach an egg and the instinctive drive of a male organism to deposit his sperm in the vagina of a female.
Explain to your roommate what the operational sex ratio is (OSR).
The operational sex ratio is defined as the ratio between sexually receptive males to sexually receptive females.
Territorial defense (male competition)
The males mark their territory and defend it against other males.Only the biggest and strongest males will breed; the smaller and younger males must wait for their turn. The females always select the best territories and mate with the strongest and most powerful males.
Fighting for mates (male competition)
Some animals compete for the provilege of mating with the females by fighting off other suitors. Females prefer to mate with a successful combatant and will often refuse to mate with the losers.
Mate defense (male competition)
Males offer the females protection against other males.
Resource Defense (male competition)
The males defend the resources that the females need for reproduction.
Mating gift (male competition)
The males compete by offering mating girft in the form of food to the females. The male's strategy is to use food as a distracting device so that he can prolong his mating with the female for as long as possible.
Scramble Competition (male competition)
The males search for and mate with females as soon as the females become sexually receptive.
Mate Attraction (male competition)
The females receive no material benefit or protection. The are shown something,such as an extravagant ornament on a male's body, a dance the male performs, or a structure that the male has built.
The ibex is an example of what type of tactic of male competition? Explain.
Fighting for mates. With the arrival of the annual breeding season, the males separate from their herd and search for the female herds. To take control of a female herd, the males rage violent battles among themselves high up on the monntain.
Explain why the red backed spider is an example of the mating gift tactic.
The male frequently becomes a meal for the female, either during or after mating.
_______ is a category of male attraction strategy, where the male will have showy feathers or vibrant plumage which is used to attract females.
Ornamental Display
Explain to your roommate what Lek Performance is.
The males use dance and vocal performances to attract sexually receptive females. During the mating season, each male bird stakes out a territory, known as a lek, as a stage for their performance.
Explain the difference between the two types of sexual selection: intrasexual and intersexual selection.
In intrasexual selection, members of the less limiting sex compete against each other to gain access to the more limiting sex. In intersexual selection, the males compete to excite and charm the opposite sex.