Trauerschnäpper
Many species demonstrate polyterritoriality, referring to the act of claiming or defending more than one territory. In the European pied flycatcher ("Ficedula hypoleuca"), researchers assert that males exhibit polyterritoriality to deceive females of the species into entering into polygynous relationships. This hypothesis, named the deception hypothesis, claims that males have territories at distances sufficiently great that females are unable to discern already-mated males. The observation that males travelled long distances, ranging from 200m to 3.5 km, to find a second mate supports this argument. The debate about polyterritoriality in this species may initiate research about the evolution and reasons for polyterritoriality in other unrelated species.