Frigatebirds are spectacular. One of their most impressive features is the large, inflatable throat sac sported by the males, used during their courtship displays. Observing and photographing Great Frigatebirds was a highlight of my visit to Genovesa Island in the Galapagos. While observing them, I noticed that the intricacies of the blood vessels and feather structure on the gular pouch were particularly noticeable when the sac was being backlit by the sun. Spotting a displaying bird, I positioned myself with the sun behind the bird to capture the most detail possible in its pouch.