Thursday, April 7, 2011

You Look This Way, I'll Listen That Way

Oxpeckers are not the only birds that zebras have been known to pair with – they also are often found in the company of ostriches. Both of these species are justifiably concerned with approaching danger [1]. Equus burchellii, more commonly known as the plain zebra, is geographically widespread. They are social animals that spend time in herds. Zebras must be constantly wary of lions and hyenas. They travel in herds so more eyes are on alert for danger. If an animal is attacked, its family will come to its defense, circling the wounded zebra and attempting to drive off predators [2]. Struthio camelus, more commonly known as the common ostrich, is found roaming around in Africa. The ostrich is the world's largest flightless bird that also travels in small herds that typically contain less than a dozen birds [3]. Ostriches have to be aware for cheetahs, lions, African wild dogs, leopards and spotted hyena. The male ostrich is a threatening opponent and will strike out at a predator, however in most cases ostriches are able to out run their pursuer [4]. Ostriches and zebras are both prepared to warn one another at a moment’s notice so they can each flee as needed.

Mutualism is a relationship between two species of organisms in which both benefit from the association. Ostriches share a mutualistic relationship with zebras. Ostriches tag along with a herd of zebras because they have a poor sense of hearing and smell, so they take advantage of the zebras strong hearing and smell senses [5]. Ostriches have a sharp sense of sight, which zebras lack. Thus, these two species rely on each other to inform one another of any nearby dangers; together they are more successful at fleeing from predators.

Cost/Benefit Analysis:
For zebras, there seems to be no cost. Ostriches are very beneficial by providing a better of sight that zebra’s lack. Ostriches also seem to have no cost. Zebras are beneficial to the ostrich by providing a sharp sense of hearing and smell which ostriches lack. Therefore, as mentioned above, these species employ a mutualistic relationship. The ostrich and zebra both benefit by utilizing each other’s senses and protecting one another from predators.



  1. Eventhough this mutualism is common, I am sure that not all zebras form a relationship with all ostriches. I am interested in hearing your opinion to the following questions. What course of action do you think evolution will take on this relationship? Will evolution bring zebra's with adaptations for better site, while the evolution for ostriches could favor adaptations for better smell and hearing capabilities? Or do you think evolution act in such a way as to bring these two species closer together, thus making this mutualism even more common?

  2. is there any other reason they have a relationship?