The Speedy Antelopes!!!- Article by Gareth Jones
The Speedy Antelopes Of The Nairobi National Park
On a recent Sunday afternoon drive while making slow progress towards the Athi basin we saw mixed herds of Thomson’s gazelle (tommies) and Grant’s gazelle near the No 10 murram heaps. As we watched them I noted a particular Grant’s gazelle that had a very pronounced black stripe on its side, making it look very different from the other Grant’s Gazelles and almost looking like a giant version of a Thomson’s gazelle. Although it is not common to see Grant’s Gazelle with pronounced black side stripes, it is recorded that Grant’s gazelle can have a significant variation in their markings. Seeing the speedy antelopes reminded me that even though they are called gazelles, they are actually not scientifically classified as gazelles. However, irrespective of their classification both the Thomson’s and Grant’s gazelles are officially listed amongst the fastest animals in the world, plus their zigzag swerving moments when threatened by predators like Cheetah does assist them to escape from being killed. While the South African Tsessebe is listed as the fastest African antelope, I believe that the smaller Springbok and Thomson’s gazelles are incredibly fast when considering their body size by proportion.
The Nairobi National Park has 2 species of antelopes that are called gazelles, namely the Thomson’s gazelle and the larger Grant’s gazelle. However, strictly speaking, according to scientific classification both of the “gazelle” species are not actually gazelles. Some years ago both of these antelope species were reclassified to a different genus. Thomson’s Gazelle is considered by some to be a subspecies of the red-fronted gazelle and was formerly considered a member of the genus Gazella within the subgenus Eudorcas before Eudorcas was elevated to genus status. The well-known Thomson’s gazelle was reclassified as Eudorcas Thomsonii. Somehow calling them Thomsons Eudorcas doesn’t sound right, but it is now scientifically correct. However, Thomson’s Gazelle physically behaves and looks very much like other gazelle species. There are 2 sub-species of Thomson’s gazelle namely the lighter coloured Serengeti Thomson’s gazelle and the wider spread Eastern Thomson’s gazelle with more pronounced markings (found in the Nairobi National Park) The lesser-known Grant’s Gazelle was reclassified as Nanger Granti. Nanger was originally considered a subgenus within the genus Gazella but has since been elevated to genus status. It is interesting to note that Grant’s gazelle, in particular, has a wide variation of sub-species with 5 being recorded in East Africa namely, Southern Grant’s gazelle, Northern Grant’s gazelle, Peter’s gazelle, Bright’s gazelle and Robert’s gazelle. The Southern Grant’s gazelle ( Nanger granti granti ) is found in the Nairobi National Park and is notably also the largest of Grant’s gazelles sub species weighting up to 80kg and standing up to 95cm at the shoulder. In comparison, Thomson’s gazelles are much smaller weighing up to 35kg and standing up to 70cm at the shoulder. It is therefore amazing that this little antelope is so very fast and agile with recorded top speeds of up to 90km/hr. A noticeable behaviour of Thomson’s gazelles is their bounding leap, known as stotting or pronking, used to startle predators and display strength. Although Cheetahs successfully hunt Thomson’s gazelles, they have to ensure their strike range is as close as possible to ensure the cheetah’s speed advantage. This is because although the cheetah can run at over 110km/hr, they can also achieve this speed for relatively short distances, while the Thomson’s gazelle and Grant’s gazelle can maintain their speed over a much longer distance.
The green grass of the plains looks magnificent after good rains, as a result, many herbivores are now having a season of plenty. There are parts of the park where mixed herds of Grant’s & Thomson’s gazelles move around together. I find it interesting that for thousands of years these two types of gazelles have lived in close proximity, and yet it seems that they have never interbred. Both species are still found in reasonable numbers inside the park, however throughout the parts of Africa and Asia where gazelles are found their numbers have dropped dramatically in recent years.
Gazelles are very adaptive in dry areas and can often survive in areas where there appears to be no water by means of gaining moisture from the plants they eat. Their enemies are predators such are cheetah, leopards, lions, jackals and Hyena, and also the super–predator MAN!! Gazelles used to be a common species in many places, but their numbers continue to drop due to complex factors mostly involving mankind. However, the Nairobi National Park continues to be a place of refuge for them.
Yes! There is much-created diversity to see in the small but very unique Nairobi national park including many other protected and rare species. After visiting the Nairobi National Park always leave satisfied with a “soul tonic” experience. Please remember “the slower the drive, the more you see what’s alive!”