The third hypothesis asserts that females settle for polygyny because it is hard to find unmated males.
This theory assumes that there is aggression between females to find mates and asserts that polyterritoriality actually helps to alleviate this aggression, allowing the second female a place to settle and breed peacefully.
Although the deception hypothesis suggests that males are more successful at farther secondary territories because they can hide their marital status, the female-female aggression suggests that males occupy distant secondary territories to reduce aggression between the primary and secondary females.
Primary females display aggression and prevent other females from settling near the initial nest to ensure that they acquire the male parental care.
Primary females were seen in experiments to visit the second territory and behave aggressively towards the secondary female.
The number of such visits decreased with increasing distance between the nests.
It is also important for the primary female to be able to detect an intruding female as soon as possible, because the longer the intruder has been present in a territory, the more difficult it will be to evict the female.
Female flycatchers are known to have the capacity to identify the songs of their own mates and check if they establish a second territory.
The primary male was also shown to spend less time in the second territories during incubation periods than before they acquired a secondary mate, especially with greater distances between the two territories.
The third hypothesis asserts that females settle for polygyny because it is hard to find unmated males. This theory assumes that there is aggression between females to find mates and asserts that polyterritoriality actually helps to alleviate this aggression, allowing the second female a place to settle and breed peacefully. Although the deception hypothesis suggests that males are more successful at farther secondary territories because they can hide their marital status, the female-female aggression suggests that males occupy distant secondary territories to reduce aggression between the primary and secondary females. Primary females display aggression and prevent other females from settling near the initial nest to ensure that they acquire the male parental care. Primary females were seen in experiments to visit the second territory and behave aggressively towards the secondary female. The number of such visits decreased with increasing distance between the nests. It is also important for the primary female to be able to detect an intruding female as soon as possible, because the longer the intruder has been present in a territory, the more difficult it will be to evict the female. Female flycatchers are known to have the capacity to identify the songs of their own mates and check if they establish a second territory. The primary male was also shown to spend less time in the second territories during incubation periods than before they acquired a secondary mate, especially with greater distances between the two territories.
European pied flycatcher