Do male Hooded Warblers guard their mates when theirpaternity is most at risk?

Males of socially monogamous species may benefit from using behavioral tactics to ensure their paternity of the young produced by their social mates. We tested whether male Hooded Warblers (Wilsonia citrina) use mate guarding and high song output in an attempt to prevent extra-pair copulations (EPC) by their mates. In this species, most EPC intrusions occur when females produce conspicuous chip vocalizations.

Bradley C. Fedy et al., J. Field Ornithol. 73(4):420-426, 2002