Final answer:
Males have the highest potential reproductive success in a polygynous mating system where one male can mate with many females, and the lowest in a monogamous system where a male mates with only one female.
Step-by-step explanation:
For males, potential reproductive success is highest in a polygynous mating system and lowest in a monogamous mating system. In a polygynous mating system, a single male mates with multiple females. This system maximizes the male's reproductive success because he can produce a larger number of offspring with different females. In contrast, a monogamous mating system, where one male mates with one female for at least a mating season, means the male's reproductive opportunities are limited to the offspring he can produce with that single partner.
The polygynous system is beneficial in situations like those found in a lek, where males gather to perform competitive displays and females select from them, as seen with sage grouse and prairie chickens. It's also seen in resource-based polygyny, such as with the yellow-rumped honeyguide, where males defend resources that attract females. However, in monogamous systems, males typically have a higher parental investment but lower potential reproductive success because they are constrained to the fecundity of one female.