Kiwi's Giant Egg: A Mystery Solved?

The flightless kiwi bird lays an egg that can weigh up to a quarter of its body mass, a phenomenon long attributed to a legacy from larger ancestors. However, new DNA analysis challenges this theory, suggesting the kiwi's giant egg is an adaptation developed as it evolved from a smaller flying bird. The oversized egg allows kiwi chicks to be more precocial, increasing their survival rate in an environment with few ground predators but numerous aerial ones. This research reshapes our understanding of kiwi evolution and avian evolutionary processes.