Mating Display of a Galapagos Frigate Bird

A male frigate bird extends his longs wings and puffs up his vibrant red throat pouch in a display to attract potential mates. Through the evolutionary process of Sexual Selection, ornate displays are often rewarded with a mating opportunity by the female. Both the sexually dimorphic characteristic of the male and the preference for that trait by the female are passed on to offspring, each becoming stronger with successive generations. This growing sexual preference for unique characteristics has the effect of wedging clear divisions between varieties within a population, allowing other advantageous traits to become more concentrated, and encouraging divergence into a clearly defined new species. And for this reason, unique mating displays of this kind are particularly common in birds, where mating boundaries could otherwise easily overlap.