The majority of animals are capable of comfortably walking in all direction: backward, forward, and sideways. Like humans, animals do most of their walking forward for obvious reasons! Although backward walking is not common among animals, it helps them escape some danger, especially when they feel threatened. Walking backward require skills in some animals while other animals can do it effortlessly. Surprisingly, some animals like kangaroo and emus cannot walk backward. Why is it so and how have they adapted to the inability to walk backward? This article focuses on why these two animals cannot walk backward and some of the animals that have a special adaptation to walking backward.
Kangaroos are large, hopping animals with pouches where they carry their offspring. For this reason, they are considered to be marsupials. Amazingly, these hopping animals cannot walk backward for several reasons. Firstly, kangaroos do not walk at all – they hop. The hopping movement is referred to as saltation. But whether they hope or crawl, they cannot do it backward. By crawling, kangaroos use their front paws to glide along the ground. The second and the most important reason why they cannot walk backward is the presence of the thick, long, and muscular tail. The tail is also not very flexible and often acts as the third leg. The feet are also big and muscular and are designed to move in a forward direction effectively and prevent the backward movement. However, kangaroos can move slightly backward in a rearward motion only during a fight to avoid injury.
Emus are flightless birds that resemble ostriches, though they are slightly shorter. Unlike their look-alike, emus can only walk forward and not backward. They can sprint forward and over a long distance because of the presence of calf muscle which is not present in other birds. However, it is not clear why this second-largest bird cannot walk backward. Many have suggested that its knee joint prevents it from moving backward.
Why is There a Kangaroo and an Emu on the Australian Coat of Arm?
Australia has so many animals that people around the world can easily recognize. Some of these animals include the platypus which appears only in Australia. However, because the kangaroo and emus cannot walk backward, the Australian authorities decided to include them on the coat of arms to symbolize the country’s resolve to only move forward and never backward.
Controversies Surrounding Other Animals
Some sources may include alligator and penguins in the list of animals that are not able to walk backward. However, studies show that these animals have special adaptions that enable them to move forward, though their backward movement may not be defined as walking. Penguins do not walk but waddle due to the combination of gravity and kinetic energy. They can waddle either forward or backward. Alligators move on land by “belly crawling.” While it cannot crawl backward, it has a backward movement called “high walk.” During high walking, the entire body and part of the tail are lifted off the ground, enabling it to walk backward. This form of movement is common then the alligator is getting out of water or climbing over an obstruction.