> This interesting and complex situation has earned this species the nickname “the bird with four sexes.” But to be clear, White-throated Sparrows do not have four different types of gonads. As in other birds, each individual typically has either two testes that produce sperm or a single ovary that produces eggs. Nevertheless, as recent research has shown, this species has much to teach us about the nature of sex variability—the way in which sex-related behaviors are influenced by genes, the complex structure of sex-associated chromosomes and the evolution of sexual reproduction itself. Importantly, this species challenges the practice of flattening nature’s wondrous diversity into two categories, male and female.<p>In one paragraph we see truth twisted into activism - no, it does not challenge the "practice of flattening nature’s wondrous diversity into two categories".<p>Sex is binary, traits are bimodal. The songbirds <i>confirm</i> this, not challenge it.