Introduction
The ostrich is the world's largest bird weighing from 140 to 320 pounds. Depending on the sex of the bird, males can range from 7 feet to 9 feet tall; Whereas, females range from 5.5 feet to 6.5 feet. Not only are they the largest bird, but they are also the fastest long distance runner with speeds of 60 kilometers per hour for 30 minutes. The main reason reason ostriches can keep up this incredible pace is the unique lower body functions.
The ostrich is the world's largest bird weighing from 140 to 320 pounds. Depending on the sex of the bird, males can range from 7 feet to 9 feet tall; Whereas, females range from 5.5 feet to 6.5 feet. Not only are they the largest bird, but they are also the fastest long distance runner with speeds of 60 kilometers per hour for 30 minutes. The main reason reason ostriches can keep up this incredible pace is the unique lower body functions.
Locomotion: Bone and Muscle
The reason an ostrich can maintain such high speeds for a long period of time is because of the bone structure. The closer the leg's muscle mass is to the body, the faster the animal can run. By comparing an ostrich skeleton to a human skeleton, it is obvious that that the ostrich's leg muscle are closer to the body compared to human leg muscles highlighted by an orange outline. Because the muscle mass is located higher in the leg, ostriches can swing their legs faster with with little effort. This is the reason why ostriches can keep the pace at high speeds. The downfall to having less muscle mass in the lower portion of the leg is there is no flexibility in terms of side to side movement. No side to side flexibility is also a positive because there is no wasted energy going into that.
The reason an ostrich can maintain such high speeds for a long period of time is because of the bone structure. The closer the leg's muscle mass is to the body, the faster the animal can run. By comparing an ostrich skeleton to a human skeleton, it is obvious that that the ostrich's leg muscle are closer to the body compared to human leg muscles highlighted by an orange outline. Because the muscle mass is located higher in the leg, ostriches can swing their legs faster with with little effort. This is the reason why ostriches can keep the pace at high speeds. The downfall to having less muscle mass in the lower portion of the leg is there is no flexibility in terms of side to side movement. No side to side flexibility is also a positive because there is no wasted energy going into that.
Locomotion: Toes
One of the most important feature about the ostrich are it's toes. Unlike most birds who have 3 or 4 toes, depending if they are flightless or not, the ostrich only has 2 toes. In addition to only having 2 toes, they are the only birds to walk on the tips of their toes.
Having only 2 toes is an advantage, especially where they inhabit. When walking, the major toe or the third toe makes most of the contact with the ground. It accounts for approximately 70% of the total force exerted. The small toe, most commonly known as the fourth toe. It can account up to 30% of the total force exerted. Up to 2% is exerted by the third toe's claw.
When running, the total force exerted is slightly different. The third toe increases to about 78% while the fourth toe decreases to a maximum value of 14%. The force exerted by the claw increases up to a maximum value of 8% because of the angle the claw comes out at. The angle of the claw is about 45 degrees so when it runs, the claw is going to be inserted into the ground, causing an increase in force.
As shown in the second picture, the left side represents a walking ostrich while the right side represents a running ostrich. As represented by the photo on the left side, the center of pressure (CoP) is located in between the third toe and the fourth toe. The reason is when an ostrich walks, the fourth toe is used for balancing, especially over uneven terrain. On the right side, the CoP is located towards the middle of the foot because both toes work together. It should also be noted that the claws are also used more when running compared to walking.
One of the most important feature about the ostrich are it's toes. Unlike most birds who have 3 or 4 toes, depending if they are flightless or not, the ostrich only has 2 toes. In addition to only having 2 toes, they are the only birds to walk on the tips of their toes.
Having only 2 toes is an advantage, especially where they inhabit. When walking, the major toe or the third toe makes most of the contact with the ground. It accounts for approximately 70% of the total force exerted. The small toe, most commonly known as the fourth toe. It can account up to 30% of the total force exerted. Up to 2% is exerted by the third toe's claw.
When running, the total force exerted is slightly different. The third toe increases to about 78% while the fourth toe decreases to a maximum value of 14%. The force exerted by the claw increases up to a maximum value of 8% because of the angle the claw comes out at. The angle of the claw is about 45 degrees so when it runs, the claw is going to be inserted into the ground, causing an increase in force.
As shown in the second picture, the left side represents a walking ostrich while the right side represents a running ostrich. As represented by the photo on the left side, the center of pressure (CoP) is located in between the third toe and the fourth toe. The reason is when an ostrich walks, the fourth toe is used for balancing, especially over uneven terrain. On the right side, the CoP is located towards the middle of the foot because both toes work together. It should also be noted that the claws are also used more when running compared to walking.
Conclusion
Modern horses have evolved from its early ancestors by changing the way it moves. Early horses had 5 toes used for moving but over millions of years of evolution, the horse has only one toe that it walks on, the hoof. Just like horses, ostriches have also evolved to move with less toes. In addition to having less toes, the leg and muscle of ostriches have also led this bird into the fastest long distance runner.
Modern horses have evolved from its early ancestors by changing the way it moves. Early horses had 5 toes used for moving but over millions of years of evolution, the horse has only one toe that it walks on, the hoof. Just like horses, ostriches have also evolved to move with less toes. In addition to having less toes, the leg and muscle of ostriches have also led this bird into the fastest long distance runner.
Works Cited
- Schaller, N., Villa, R., Herkner, B., Aerts, P. Toe Function and Dynamic Pressure Distribution in Ostrich Locomotion, December 10, 2010. Web April 23, 2014. http://jeb.biologists.org/content/214/7/1123.full
- Schaller, N. Bird on the Run, November 22, 2011. Web April 23, 2014. http://www.scienceinschool.org/2011/issue21/ostrich