The blue-footed booby (Sula nebouxii) is a marine bird in the family Sulidae, which includes ten species of long-winged seabirds. Blue-footed boobies belong to the genus Sula, which comprises six species of boobies. It is easily recognizable by its distinctive bright blue feet, which is a sexually selected trait. Males display their feet in an elaborate mating ritual by lifting their feet up and down while strutting before the female.

A panda bear sits on a logs in a zoo on January 15, 2015 in Hangzhou, China. (Photo by Feature China/Barcroft Media)

A gravedigger competes as a boy looks on during the first National Grave Digging competition at the public cemetery of Debrecen, 226 km east of Budapest, Hungary, Friday, June 3, 2016. Eighteen two-man teams of Hungarian gravediggers are demonstrating their skills for a place in a regional championship to be held in Slovakia. (Photo by Zsolt Czegledi/MTI via AP Photo)

South Korean university students prepare for an establishment ceremony of the Reserve Officer Training Corps (ROTC) for female cadets at Sookmyung Women's University on December 10, 2010 in Seoul, South Korea. The South Korean defense ministry has agreed to admit women into it's college-based Reserve Officers' Training Program for the first time since the program began in 1963. (Photo by Chung Sung-Jun/Getty Images)

A preparatory model of the Imperial State Crown of India worn in 1911 by King George V stands next to original ledgers dating from 1735 in Garrard's flagship store in Mayfair on April 6, 2011 in London, England. Garrard is the world's oldest jewellers having been founded by George Wickes in 1735 and soon after appointed as goldsmith to the Prince of Wales. For over 160 years Garrard held the title of Crown Jeweller, bestowed by Queen Victoria in 1843, Garrard have served six successive monarchs. They have produced several royal crowns as well as the engagement ring presented to Kate Middleton by Prince William and formerly Princess Diana's engagement ring. (Photo by Oli Scarff/Getty Images)

A horse-drawn cart passing through a section cut out of the base of a giant sequoia tree in the Mariposa groves of Yosemite Park, California. (Photo by Carleton E Watkins/Getty Images). 1870

A Filipino worker arranges roasted pigs which they sell in suburban Quezon city, Philippines on Tuesday, December 23, 2014. Roasted pig is popular during Filipino celebrations and traditionally served during a Christmas eve dinner called “Noche Buena” in this predominantly Roman Catholic nation. (Photo by Aaron Favila/AP Photo)

Humanoid robot bartender “Carl” interacts with guests at the Robots Bar and Lounge in the eastern German town of Ilmenau, July 26, 2013. “Carl”, developed and built by mechatronics engineer Ben Schaefer who runs a company for humanoid robots, prepares spirits for the mixing of cocktails and is able to interact with customers in small conversations. (Photo by Fabrizio Bensch/Reuters)