The white-tailed kite was described in 1818 by the French ornithologist, someone who studies birds, Louis Pierre Vieillot under the binomial name Milvus leucurus with the type locality as Paraguay.

The specific epithet leucurus is from the Ancient Greek leukouros for "white-tailed": leukos is "white" and oura is "tail".

[n 1] White-tailed kites typically nest at the top of trees, usually around 20 to 50 feet above ground level.

[10] White-tailed kites feed principally on rodents (as well as small opossums, shrews, reptiles, amphibians and large insects),[11] and they are readily seen patrolling or hovering over lowland scrub or grassland.

They rarely if ever eat other birds, and even in open cerrado, mixed-species feeding flocks will generally ignore them.

This means that instead of returning to a perch to feed, these birds transfer the prey from their talons to their beaks while flying to eat.

[15] White-tailed kites have been observed in aerial combat at the margins of territories, locking talons in a behavior described as "grappling".

Meanwhile, smaller birds like American crows, common ravens, and small to medium-sized carnivores will go for the eggs of white-tailed kites.

[17] Deforestation and urban expansions have caused the number of white-tailed kites to decrease as they lose suitable places to live and truly thrive.