Too many male zoo animals may threaten endangered species conservation efforts

The largest-ever study of over 2.6 million zoo birth records reveals skewed sex ratios in endangered species, from lemurs to elephants. The international team of scientists behind the study emphasizes that it is vital that zoos take into account the ratios of males to females born in captivity when planning conservation projects and breeding programs for endangered species to avoid the silent threat of having too many of one sex.