[2] Like the black-legged seriema, farmers often use them as guard animals to protect poultry from predators and sometimes human intruders.

[3] The red-legged seriema was described in 1766 by the Swedish naturalist Carl Linnaeus in the twelfth edition of his Systema Naturae.

[4] The red-legged seriema is now the only species placed in the genus Cariama that was introduced by the French zoologist Mathurin Jacques Brisson in 1760.

[7] The German naturalist Georg Marcgrave used the Latin word Cariama for the red-legged seriema in his Historia naturalis Brasiliae, which was published in 1648.

Though it likes to inhabit lush meadows near rivers, it will not readily move into wetlands or crop fields.

[16] Territorial defense may involve agonistic confrontation between individuals, initially characterized by full vocalization duets followed by short runs and flights towards intruders, alternated with claws and beak attacks.

[16] Diets mainly consist of arthropods (such as grasshoppers, beetles, ants and spiders), insect larvae, lizards, amphibians, snakes, rodents and other small vertebrates; occasionally, corn (Zea) grains and other crops, wild fruits and tree gum.

[2] Seriemas typically feed alone or in pairs, seasonally in small family groups; they forage by walking steadily, looking for food on the ground or in low vegetation.

The researchers note that very few red-legged seriema broods fledge three young and speculate that the third nestling serves as reserve food for the other two in times of stress.

[23] During the breeding season, the male, more intimidating or forcing himself on the female, spreads out his wings laterally, moving them forward and displaying the contrasting arrangement of the flight feathers, a pattern similar to that of certain birds of prey, such as the African secretarybird (Sagittarius serpentarius).

The chicks are coated with long, light brown feathers and are fed by both parents; initially, they weigh around 40–60 g (1.4–2.1 oz).

At this time, the chick is able to make a call similar to the adult vocalization, although very faint,[23] to attract the parents' attention to itself.