What characteristic do all true falcons share?

All true falcons are distinguished by their unique anatomical feature—a notched beak. This notched shape is particularly important for their hunting technique, as it allows them to easily tear flesh from their prey. The notch aids in delivering a lethal bite, which is effective for dispatching smaller birds and mammals that make up a significant portion of their diet.

While strong talons are indeed a common trait among birds of prey, and some falcons may hunt larger animals depending on their species, these features are not exclusive to true falcons. Additionally, while many birds of prey may build nests in trees, not all falcons do so, as their nesting habits can vary widely. The notched beak is a defining characteristic that is consistently present across all true falcon species, making it the most accurate answer in this context.