# Talk:Cheetah

Cheetah urine is unique in that it lacks odour or a distinctive chemical scent marker.
It has been found that cheetahs do not excrete sulfur through their urine as organosulfur compounds, which would give their an odour.
Instead, they excrete pure elemental sulfur through their urine.
It is unclear why cheetahs developed this peculiar chemical characteristic, but it has been suggested that it could be a way to avoid detection by other animals.
In experiments conducted at two wildlife management centers, cheetah urine was presented to lions, tigers, caracals, African wild cats, African wild dogs, as well as other cheetahs, and the cheetah urine elicited no reaction in any of the animals.
Based on this, it has been suggested that the odourless urine of cheetahs allows them to pass "invisible to the olfactory radar" of other animals.
This could be useful both to prevent predators from tracking them and to prevent prey from avoiding the routes taken by cheetahs.

https://doi.org/10.1007/s10886-006-9056-5 
https://www.academia.edu/101755453/Elemental_Sulfur_Identified_in_Urine_of_Cheetah_Acinonyx_jubatus 
LeandroPucha (talk) 13:25, 24 September 2025 (UTC)

Here is a compilation of the concentration of fast-twitch glycolytic muscle fibres, or type IIx, in cheetahs and other athletic animals, compared to humans.
This concentration will be shown as a percentage and will be seen for the vastus lateralis muscle.

-Wild cheetahs: 76%.
-Captive cheetahs: 62%.
-Wild springboks: 58%.
-Wild mountain reedbucks: 57%.
-Wild blesboks: 55%.
-Wild European fallow deer: 48%.
-Wild greater kudus: 43%.
-Wild black wildebeests: 30%.
-Recreationally active humans: 7%.

As an extra, I will also show the concentration of fast-twitch oxidative-glycolytic muscle fibres, or type IIa, in domestic animals known for their athleticism.
(Type IIa fibres have a lower capacity for using glycolysis without oxygen and creatine phosphate, and therefore less powerful contractions than type IIx fibres, but their greater use of oxygen gives them more resistance to fatigue).

-Racing greyhounds: 76%.
-Racehorses: 61% (although this is the percentage for the vastus medialis muscle).

I will also show the level of activity of the enzyme lactate dehydrogenase (LDH) in the muscles of these animals compared to that of human muscles, an indicator of the muscle's greater capacity to use glycolytic and anaerobic energy sources (glycogen and creatine phosphate) as fuel, and a lesser capacity to use oxygen.

-LDH activity is nine times higher in wild cheetahs than in humans (and 2.8 times higher than in racehorses, although LDH activity in horses was observed in the vastus medialis).

-The activity of this enzyme is six times higher in captive cheetahs than in humans.

-LDH activity is four times higher in wild antelopes than in humans.
(Differences in type IIx fibers concentration between species possibly due to differences in body mass).

-LDH activity is three times higher in greyhounds than in humans.

These two muscular characteristics in cheetahs indicate muscular adaptations for high-intensity, short-duration physical exertion (anaerobic muscular activities) and help explain the speed of this species.

https://www.researchgate.net/publication/13826213_Skeletal_muscle_histology_and_biochemistry_of_an_elite_sprinter_the_African_cheetah 
https://doi.org/10.1242/jeb.247284 
https://doi.org/10.1242/jeb.073684 
https://doi.org/10.1242/bio.20149241 
https://doi.org/10.1002/ar.25207 
https://www.researchgate.net/publication/19946267_The_similarity_of_mitochondrial_distribution_in_equine_muscles_of_differing_oxidative_capacity 
https://doi.org/10.1242/jeb.061572  LeandroPucha (talk) 17:14, 2 October 2025 (UTC)

UPDATE:
I found comparative data for cheetahs and other animals concerning to type IIx muscle fibers concentration for overall musculature of the hind limbs, neck, and trunk (including extrinsic muscles of the forelimbs and abdominals), and for the forelimbs (only the arm and forearm).
Here is the concentration of fast-twitch glycolytic or type IIx muscle fibres in cheetahs and other ‘powerful’ animals (so to speak).
•Cheetahs:
-Hindlimbs: 50.1%.
-Neck and trunk: 40%.
-Forelimbs: 36%.
•Thoroughbred horses:
-Hindlimbs: 19.5%.
-Trunk: 16%.
-Abdominals: 2.8%.
-Head and neck: 3.7%.
-Forelimbs: 7%.
•African savannah elephant:
-Hindlimbs: 11.4%.
-Neck and trunk: 11.4%.
-Forelimbs: 20.8%.
(Note: Domestic cats also appear to have a similar concentration of type IIx fibers than that of cheetahs, so the difference in locomotor performance between these two animals may be due to the difference in muscle mass in the hind limbs, with cheetahs having more locomotor muscle than cats but maintaining a similar concentration of type IIx fibers; the longer length of the limbs in relation to the body mass in cheetahs may be another determining factor).
-Megumi Goto, Kazuhiko Itamoto, Yuuki Tani, Hirofumi Miyata, Ichiro Kihara, Futoshi Mori, Takamitsu Tajima, and Naomi Wada "Distribution of Muscle Fibers in Skeletal Muscles of the African Elephant (Loxodonta africana africana)," Mammal Study 38(2), 135-140, (1 June 2013).
-Kawai M, Minami Y, Sayama Y, Kuwano A, Hiraga A, Miyata H. Muscle fiber population and biochemical properties of whole body muscles in Thoroughbred horses. Anat Rec (Hoboken). 2009 Oct; 292(10):1663-9.
https://doi.org/10.1002/ar.20961
-Goto, M., Kawai, M., Nakata, M. et al. Distribution of muscle fibers in skeletal muscles of the cheetah (Acinonyx jubatus). Mamm Biol 78, 127–133 (2013).
https://petit.lib.yamaguchi-u.ac.jp/search/item/21358  LeandroPucha (talk) 05:18, 22 November 2025 (UTC)

It has been estimated that cheetahs could lose up to 25% of their hunts to other predators without dangerously compromising their energy recovery (i.e., without significantly compromising their survival). 
Reports of kill losses in cheetahs range from 9.3–14%, so the reported hunt loss rate in the wild does not really affect this species at all. 
The cheetah's short pursuits (37.9 seconds on average) could allow for this greater energy flexibility compared to another carnivore which also loses its hunts to other predators, the African wild dog. 
Cheetahs spend an average of 2.86 hours per day hunting, compared to the 3.5 hours per day spent hunting by the African wild dog. 
(2.86 hours per day even with a 9.3% kill loss rate reported for cheetahs in this particular paper**). 
The power required for the African wild dog's hunting strategy is 35 Watts/kg, compared to the 120 W/kg of power required for the cheetah's hunting strategy. 
This tells us that time is a more important factor than the amount of energy itself in determining energy expenditure and consumption. 
The cheetah's high-speed and short-duration pursuit strategy is more energy-efficient than the African wild dog's lower-speed and longer-duration pursuit strategy. 
With a 25% kill loss rate included, cheetahs should only need to spend about 4 hours per day hunting. 
In comparison, a 25% kill loss rate for African wild dogs would require them to spend 12 hours per day hunting, which is quite impractical in the long term. 
If the kill loss rate exceeds 50% in cheetahs, they would have to spend more than 9 hours per day hunting, and then recovering the energy expended becomes impossible for them (compromising the survival of the species).
**https://www.researchgate.net/publication/266401453_Mammalian_energetics_Flexible_energetics_of_cheetah_hunting_strategies_provide_resistance_against_kleptoparasitism 
https://www.academia.edu/4686614/High_hunting_costs_make_African_wild_dogs_vulnerable_to_kleptoparasitism_by_hyenas  LeandroPucha (talk) 02:15, 27 October 2025 (UTC)