The reproductive success of a female mammal depends on a few factors such as safe territory, brood feeding area, and resources such as food availability (Stockley amp. Bro-Jorgenson, 2011, pg344). The male members of the mammalian species, on the other hand, wander far away from the nest in search of possible female mates who defend their own territories. Thus, we can say that the reproductive success among mammals depends largely on its female members.
However, males of avian species are the ones that remain on or near the natal territory since in case of birds it is the quality of the habitat that the male defends that determines the reproductive success (Hill,1988,p379). Reproductive success among avian species depends on the male members and on the provisions available for the brood and attraction of female birds in the territory defended by the males.
Therefore, remaining within or near the natal territorial range in case of male birds is more beneficial since they are able to attract females while in case of mammal males, remaining near natal territory is not beneficial since the reproductive success depends solely on the female members of mammalian species.