One explanation for why females favour long tails in male long-tailed widowbirds is that the expanded tail enlarges the lateral surface area of the male by 2–3 times, making him much more visible from far distances over open grassland. However, this is most likely not the whole explanation, especially considering that prior to mating, females spend a great deal of time comparing males and, thus, do not rely on sighting them from a distance. As of this time, the exact function of epaulette in male long-tailed widowbirds is unknown. However, its use does resemble that of the red-winged blackbird, being displayed during courtship and threat displays. Thus, the two most conspicuous ornaments of the male birds in the two species may be favoured by different forms of sexual selection: the tail of the long-tailed widowbird by female choice and the brightly coloured epaulettes of the long-tailed widowbird and red-winged blackbird by male contest competition.
