Alpacas peek out of their box in Kielnarowa, Poland, June 11, 2014. A total of 35 female and 3 male alpacas were imported from Chile by the Rzeszow University of Information Technology and Management Center Zoo to be used for the therapy of children. Alpacas also provide one of the most expensive wools. (Photo by Darek Demanowicz/EPA)

Komodo Judo by Andrey Gudkov. Finalist, Amphibians & Reptiles. Two large male Komodo dragons hissing angrily at each other in Indonesia’s Komodo national park. Komodo dragons can grow up to 8ft. (Photo by Andrey Gudkov/Wildlife Photographer of the Year 2015)

Inmates stand next to food during a Christmas event at Sarita Colonia male prison in Callao, Peru, December 18, 2015. For the event, inmates prepared Christmas meals for a culinary competition and took part in dances and songs. (Photo by Mariana Bazo/Reuters)

The males, of the Oriental Garden species, are battling over territory in Solapur in the Maharashtra state, India on May 20, 2022. Occasionally, the tussle can be brutal, ending in a fatality with one lizard biting another to encourage them to retreat. (Photo by Ratnakar Hiremath/Solent News)

A family take a souvenir picture next to giant male panda Xiao Liwu, who was born at the San Diego Zoo and will be repatriated to China with his mother Bai Yun, bringing an end to a 23-year-long panda research program in San Diego, California, U.S., April 18, 2019. (Photo by Mike Blake/Reuters)

A fight between two female musk oxen, Norway, 2021. The image was captured in Norway’s Dovrefjell national park, where the musk ox (Ovibos moschatus) was reintroduced several years ago for its conservation. It is normal for males of this species to engage in fierce battles during the mating season but unusual for two females. (Photo by Miquel Angel Artús Illana)

The Greater Sage-Grouse is certainly a formidable-looking bird. Being the largest grouse in North America and having tail feathers, which look like giant spikes, make for a ferocious sight. These birds are well known for their complicated courtship rituals, in which the males perform a special “strutting display” to attract the females. Another distinct feature of the Greater Sage-Grouse is two large yellow throat sacs (gular sacs), which are inflated by the males during the courtship display. Unlike pelicans, whose gular sacs are used to store fish while hunting, the throat sacks of the Greater Sage-Grouse are merely for display.