The Evolutionary Ecology of The Bird Nests, David Ocampo, GS (CA48F7FC)

Birds build diverse nest types, and this ability might be why some groups have thrived throughout their evolutionary history. Passerine birds, including the tyrant flycatchers, have managed to spread and succeed in diverse environments. The tyrant flycatchers are found throughout the Americas, where they occupy a wide range of habitats and exhibit different nest-building behaviors. Our study aimed to explore how these nest types have evolved. To do this, we examined the nests of various tyrant flycatchers and their close relatives, tracing back to infer the likely nest structures of their ancestors. Additionally, we investigated whether these evolutionary changes in nest design were related to the types of habitats these birds occupy. We found that the ancestors of this group probably built cup-shaped nests in forested regions. As time passed, dome-shaped nests began to emerge, occurring independently at least 15 times within the family. This diversity in nest styles allowed both cup- and dome-nesting birds to eventually expand into open habitats, like savannas and grasslands. Despite this significant variation, we couldn't establish a clear link between nest type and habitat type. Likewise, other ecological and environmental factors didn't appear to heavily influence nest design. This finding suggests that the range of nest designs among these birds isn't driven by a single factor but rather by a complex mix of influences. Bird nests are fascinating structures with intricate evolutionary histories, and they play a critical role in the survival of birds, offering them protection in a constantly changing world.