On the Indonesian island of Java, at least 75 million birds live in cages as pets; of some species such as the Java bushelster (Cissa thalassina) or the Blackwing Maina (Acridotheres melanopterus) there are now more animals in captivity than in the wild. And Java is just one of many countries where wild birds are kept en masse. Rebecca Senior of Durham University and her team have now identified a link between the coloration of songbirds and their risk of extinction, as they explain in »Current Biology«: The more colorful and uniquely colored a species is, the higher its risk of extinction.
The working group’s analysis shows that the tropics are the global hub of colorful birds: these regions are home to more than 90 percent of the most colorful species and nearly two-thirds of species that display a unique color pattern. At the same time, one third of all bird species are affected by the pet trade. The dealers aim particularly intensively at certain related groups that are strikingly intensely colored and often also have unusually euphonious voices. For example, they form the core of the Southeast Asian songbird crisis, which clears entire forests and lets them fade away. Parrots are also in demand.
Based on these relationships, the scientists identified a further 500 species of songbirds that could increasingly become the focus of catchers and keepers in the future once the populations of their current favorite animals have been exhausted. In addition to bright blue, red or yellow species, bright white species are also particularly threatened. A classic example of this is the Balistar (Leucopsar rothschildi), who is completely white except for his blue eye-ring. In the wild, bird trappers had almost wiped him out; today it survives only in a few places. And poachers even raided breeding stations to steal the valuable animals.