Which Animals Can Walk on Two Legs for Long Distances?

When considering which animals can walk on two legs for long periods, one might naturally think of Homo sapiens, yet other fascinating creatures share similar capabilities. This article explores a range of animals that are adept at bipedal locomotion, from humans to ostriches and beyond. Whether it's for survival, speed, or simply energy efficiency, these impressive gaits of long-distance locomotion are worth exploring.

Bipedal Locomotion in Animals

Bipedal locomotion refers to the ability of an animal to walk or run on its two hind legs. This unique form of movement is not restricted to humans. Certain animals, such as ostriches, emus, and secretary birds, are known for their remarkable long-distance walking abilities. Despite the name, kangaroos do not qualify as bipedal walkers due to their distinctive jumping gait, which is more akin to bouncing rather than walking.

Ostriches and Long-Distance Walking

Ostriches are among the most well-known animals capable of sustained bipedal walking. Standing at heights of up to 2.8 meters (9 feet), these large birds can run at speeds of up to 70 kilometers per hour (43 miles per hour) for short bursts and walk for extended periods at a relatively slow pace. Their large gauge and powerful legs allow them to cover large distances efficiently, making them well-adapted to their desert and grassland habitats. Ostriches use a stilt-like gait, where each step involves the dragging of a leg sideways before it reaches the ground. This unique walking pattern helps them to conserve energy and maintain balance while traveling vast distances in search of food and water.

Emus and Their Walking Habits

Emus, closely related to ostriches and also flightless, are another example of animals that walk on two legs. Emus can reach speeds of up to 50 kilometers per hour (31 miles per hour) and can walk for long distances without tiring. Their slightly different gait allows them to move more fluidly compared to ostriches. Emus are native to Australia and are often found in open grasslands and woodlands. Their walking ability is crucial for grazing, which is their primary food source, and to evade predators. Emus walk with a distinctive rocking motion, which helps them to maintain balance and conserve energy while moving over flat terrain.

Secretary Birds and Their Hunting Techniques

Secretary birds are another excellent example of animals that walk on two legs. Named after the quill-like feathers that dangle from their heads, resembling a secretary's quill pen, these birds are indigenous to Africa. Unlike ostriches and emus, which are primarily grazers, secretary birds are predatory and hunt their prey on the ground. They can run at speeds of up to 20-30 kilometers per hour (12-19 miles per hour) for short distances and walk for extended periods when pursuing prey. Secretary birds have long, sharp talons and a sturdy body, making them effective hunters. Their bipedal walking helps them to traverse large areas of savannah and grasslands in their hunt for food.

Other Notable Bipedal Walkers

Other animals that can walk on two legs for long periods include cassowaries and roadrunners. Cassowaries, similar to ostriches and emus, are flightless birds native to New Guinea and northeastern Australia. They are known for their powerful legs and can run at speeds of up to 50 kilometers per hour (31 miles per hour), although they do not maintain these speeds for long periods. Cassowaries use a rapid walk and occasional running to navigate their rainforest habitats, often traveling long distances to find food and mates. Roadrunners, on the other hand, are a New World bird species that combine both running and flight. They can run at speeds of up to 18-20 kilometers per hour (11-12 miles per hour), making them agile runners in their desert and grassland habitats. Roadrunners also possess a unique ability to dig and hide their prey, which they capture with their sharp beaks and feet.

Why Do Animals Walk on Two Legs?

The ability to walk on two legs is an adaptation that offers several advantages to animals. For most of these bipedal walkers, it allows for energy efficiency, faster movement, and better visibility. Ostriches and emus, for instance, use their bipedal gait to cover vast distances while expending minimal energy. This is particularly beneficial in desert and savanna environments where resources may be few and far between. Secretary birds, by contrast, use their bipedal walking to efficiently pursue and capture prey. Roadrunners have a hybrid gait system, balancing running and walking to adapt to both open terrain and rocky areas.

For humans, bipedal locomotion is a defining characteristic of our species, with evolutionary advantages that include better field of vision, upright movement, and the ability to carry objects while walking. This adaptation has played a crucial role in our survival and success as a species, enabling us to explore and adapt to a wide range of environments.

Conclusion: While bipedal locomotion is often associated with Homo sapiens, many other animals possess this remarkable ability. Ostriches, emus, secretary birds, and roadrunners are among the most notable for their long-distance walking prowess. Understanding these unique gaits can provide insights into the adaptations and survival strategies of these fascinating creatures.