IMG_6945

 

Anne Hilborn

IMG_5083 IMG_5084

Blog

In my blog I ramble on about various aspects of cheetahs and doing fieldwork that interest me. There is the occasional tangent about academia, but mostly it is cheetah pictures.

WHY CHEETAHS NEED SPACE

By Anne Hilborn, Apr 19 2016 07:16PM


Cheetahs need space. A lot of space.


One of the reasons is to avoid competitors and predators. Lions kill cheetahs cub [1] and hyenas (and occasionally lions) steal their hard earned kills [2] In order to successfully raise cubs and be able to feed themselves, cheetahs need to find areas where there aren’t many lions and hyenas and yet there are gazelles to eat and habitat to den their cubs. Even in Serengeti, no such cheetah paradise exists, at least not in the long term.




The short grass plains of Serengeti


The spatial rhythms of carnivores in Serengeti are largely driven by migrations of herbivores and the herbivore migration follows the rains. Rains can be patchy, habitats are varied, and lions and hyenas focus on wildebeest and zebra while cheetahs love tasty gazelle. Cheetahs exploit the varied nature of the herds and the landscape to spend more time on the edges of herds instead of the thick of things where lions and hyenas hang out [3]. Cheetahs are good at hunting in low prey densities, they especially like male Thomson’s gazelles who are solitary or on edges of the herd [4]. Male gazelle tend to be a bit less vigilant which allows cheetahs to stalk close enough to launch their full on high speed chase. And once a cheetah starts chasing, they have about a 50% chance of success [5]. So being on the edges of herds in low prey density areas is good for cheetahs. There are fewer lions and hyenas and enough prey. But as herds are constantly shifting and moving, this means cheetahs have to move along with them. No area is great for cheetahs at all times of year.




Sheridan chases a lone male Thomson's gazelle. And fails to catch it



Asti with a tasty male Thomson's Gazelle



Cheetahs need space and to be highly mobile in order to find the refuges from other predators. But what happens when they can’t move? This is the case with mothers with very young cubs. Cheetahs give birth in dens which are usually in swampy areas with tall reeds, or in rock outcroppings (kopjes). For two months that the cubs are in the den, the mother is limited in how far she can go in search of prey each day as she has to come back and suckle the cubs. If there are enough prey around to feed her heightened nutritional needs (making milk is energetically expensive) things are dandy. But what if the prey move away? A single cheetah would follow them, no problem, but a mother with small cubs can’t. Instead she will have to make daily trips to find prey. And as new research has shown, it is walking that is energetically costly for cheetahs [6]. So there is a limit to how far mothers can go, if they have to go too far, they can end up abandoning the cubs. Another stressor on mothers is that unfortunately lions also like swamps and kopjes. This is bad news for cheetah cubs as cub mortality is very high (95% born do not make it to become independent from their mothers at 18 months) and 70% of that mortality is caused by lions and hyenas [1].


The search for prey can be exhausting.



Thus because they are tied to the den, mother cheetahs are much more likely to be around other carnivores than cheetahs that do not have such constraints [3]. Most other cheetahs get the hell out of dodge if they see lions, but mothers with cubs in the den can’t, they have to stay near the den to try to protect their cubs if possible. Lions don’t just kill cheetah cubs, they are known to also kill adults, so not only do they pose a threat to her cubs, but also to herself.




Armitage just wanted a nice patch of shade to lie down in, but quickly decided to find alternate shade with fewer lions in it.




A good cheetah mother is one who can manage to den her cubs somewhere they are not discovered and killed by lions (no easy feat that), and manages to feed them and keep them safe as they grow. In this respect, not all cheetah mothers are the same. Research suggests that avoiding lions is a learned skill, and those females who are better at avoiding lions have more cubs that survive [7]. Young cheetah mothers have a lot to learn about where to den cubs so that there is enough food around over two months to feed them and not so many lions. Not all females get the hang of it. Some are a bit thick and don’t seem to avoid predators as well. There is a large variety in quality of mothers. Some are super moms and some are just crap at the whole business. Since lions cause so much cub mortality, the ability to avoid predators may be a driving factor in whether a cheetah is a good mother or not.



Cambazola was a lovely cheetah, but didn't really seem to be bothered by the whole raising cubs thing




While Amarula was a super mom



The moral of the story is that cheetahs need space. They need enough space to find refuges from predators and find food. This is why despite the Serengeti being so large (14,750 km2), cheetahs are pretty sparse on the landscape. There are only so many places where they can avoid ~3000 lions and ~9000 hyenas. It is the size of Serengeti ecosystem that contributes to it being a stronghold for cheetahs. With room enough to avoid other carnivores and a social system that allows them to be very mobile, cheetahs can persist in landscape full of larger predators.



Add a comment
* Required
RSS Feed

Web feed