When a female blue-footed booby goes on a search for the perfect mate she is looking for something very specific. She’s not concerned about how tall her suitor is or how strong his mating call may be. She’s focusing on his feet. And it’s the males with the brightest blue feet that she finds the most attractive. The blue pigmentation comes from the marine bird’s diet of fresh ocean fish such as anchovies, mackerel and sardines. The carotenoids that these fish provide directly impact the colour of the booby’s feet, making them a vivid barometer of a male’s state of fertility. Studies have shown that healthy males make for caring fathers by actively contributing to a chick’s upbringing. It also helps that their big blue feet keep eggs warm during the gestation period.
This brings us to the mating process. Male blue-footed boobies are known to put on quite a show. They extend their wings, confidently point their heads back, lift beaks to the sky and proceed to brandish their webbed feet, one blue foot at a time. The high-stepping booby continues to show off his wares until such time as the female accepts him. This slaphappy routine is where the bird gets its name from. It is derived from the Spanish word “bobo,” meaning stupid or foolish. Despite how silly the dance may look, it gets the job done. Sometimes unusually effective ideas come right out of the blue.