Common chiffchaff the male has little involvement in nesting, but defends his territory against rivals, and attacks potential predators. A small insectivorous bird, it is subject to predation by mammals, such as cats and mustelids, and birds, particularly hawks of the genus "Accipiter". Its large range and population mean that its status is secure, although one subspecies is probably extinct. The British naturalist Gilbert White was one of the first people to separate the similar-looking common chiffchaff, willow warbler and wood warbler by their songs, as detailed in 1789 in "The Natural History and Antiquities of Selborne", but the common chiffchaff was
The Origin of Birds the reptile." He also finds the eyes of birds and reptiles to be remarkably similar, especially the development of the lens, as well as the ear, which reveals a much wider gap between the Sauropsida and mammals than with birds. He describes the sexual organs of birds and reptiles to likewise be structurally similar, and finds that while most species of male bird have lost the penis to reduce weight, those that retain it bear remarkable similarities to extant reptiles. He writes that secondary sexual characteristics are also similar between birds and reptiles, with both groups frequently utilizing bright colors