Rheas are large, flightless birds native to South America, primarily found in countries like Argentina, Brazil, and Chile. They belong to the family Rheidae and are known for their long legs and necks, which help them run swiftly across open grasslands and savannas. Rheas can reach heights of up to 5.5 feet and weigh between 55 to 100 pounds. These birds are omnivorous, feeding on a diet that includes plants, seeds, and insects. Rheas are social animals, often seen in groups, and they play a significant role in their ecosystem by helping to disperse seeds. They are also known for their unique breeding behavior, where males incubate the eggs laid by multiple females.