How does the Eastern Kingbird's intense territorial behavior change upon reaching its tropical wintering grounds?

Answer

The intense territoriality often dissolves, and they associate in looser groups

In the tropics, where the pressure to reproduce is absent and insect abundance is high, the fierce, solitary territorial defense seen in summer dissolves, leading to looser foraging associations.

How does the Eastern Kingbird's intense territorial behavior change upon reaching its tropical wintering grounds?
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