Why do nightjars often prefer open habitats such as grasslands and forest clearings?

Nightjars prefer open habitats such as grasslands, savannas, and forest clearings primarily because these areas provide them with a distinct ecological advantage. By occupying these open spaces, nightjars face no effective avian competitors for the vast numbers of night-flying insects that serve as their primary food source.1

While some nightjars are woodland dwellers, they typically utilize those environments only for daytime concealment or nesting. Even in forested regions, these birds generally conduct the majority of their feeding at the forest edge or within clearings. This preference for open areas allows them to exploit a niche that is largely free from competition, contributing to their status as the most successful and widespread group within the order Caprimulgiformes.1