cursoriality

Cursoriality refers to the anatomical and behavioral adaptations of animals that have evolved for efficient running. These adaptations enable cursorial species to move swiftly and efficiently over land, often as a primary mode of locomotion. The term originates from the Latin *cursus*, meaning "running," and is commonly applied to animals that have specialized for speed and endurance.

Cursorial animals typically exhibit several key morphological features. Their limbs are often elongated and streamlined, reducing drag and increasing stride length. The bones of the legs are frequently hollow or lightweight, which aids in reducing overall body mass without compromising strength. Additionally, cursorial species often have enlarged muscles, particularly in the hind limbs, which provide powerful propulsion. The placement of the feet may also be adapted, such as being positioned beneath the body for greater stability or extended forward for increased stride efficiency.

Behaviorally, cursorial animals may exhibit patterns of movement that maximize speed and energy efficiency. Many species, such as cheetahs or gazelles, rely on short bursts of high-speed running to evade predators or capture prey. Others, like horses or antelopes, may engage in prolonged endurance running, covering vast distances over time. These behaviors are often supported by physiological adaptations, such as efficient respiratory and cardiovascular systems.

Cursoriality is observed across various taxonomic groups, including mammals, birds, and reptiles. For example, the cheetah (*Acinonyx jubatus*) is one of the most well-known cursorial mammals, capable of reaching speeds up to 100 kilometers per hour (62 miles per hour) in short sprints. Similarly, the ostrich (*Struthio camelus*), the largest living bird, is highly adapted for running, achieving speeds of up to 70 kilometers per hour (43 miles per hour) and using flight primarily for escape rather than sustained travel.

While cursoriality is often associated with speed, it can also involve adaptations for endurance, balance, or agility depending on the ecological niche of the species. These adaptations highlight the diversity of evolutionary solutions that have emerged to optimize movement across different environments.