The adorable Owl Finch (Taeniopygia bichenovii)

Male and female Owl Finches look nearly identical, although females might have slightly narrower bands and their chests may be less brilliant white. Such differences are subtle, though, so it’s nearly impossible to determine sex based on coloring alone. However, there is a telltale giveaway about the sex of an Owl Finch: Only male Owl Finches sing.