Answer: Polygamy
Explanation:
Polygamy concept in terms of zoology is defined as the behavior shown by any person or animal by engaging into a romantic and mating relationship with the one or more different individual.The partner with which they get involved is of opposite gender.
According to the question, if a black bird is seen involved in a romantic relationship with a brown bird then it is depicting the example of polygamy theory.As the behavioral pattern shown by the birds getting into courtship with another kind of birds that displays different or multiple partner scenario
