Intrasexual competition

The odor of ferret, Mustek putorius furo, urine causes male outbred laboratory Mus musculus, to reduce their overmarking of rival urine marks. These mice reduce predation risk at the price of tolerating more intrasexual competition (Roberts etal., 2001). 

Intrasexual competition is also a very important factor influencing mating behavior insects have developed a series of strategies in competing for a potential mate and the necessary food resources. Young rove beetle males, Aleochara curtula, which are not sexually active yet, but need access to food sources avoid aggressive encounters and expulsion by mimicking the female sex pheromone 438). 

In mammals, males usually have stronger odors, larger and/or more scent glands, scent mark more often, and respond more to alien scent marks. Selection on the basis of odor differences can take place at the level of the individual, deme, population, or subspecies. In polygamous species, intrasexual selection via male-male or female-female competition and sexual selection can be most intense. Most mammals are polygamous, so odor dimorphism is probably widespread (Blaustein, 1981). 

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