Chapter 1: The Puma

The Puma (Felis concolor) is also known as the mountain lion and couguar. It is northern North America’s largest cat. - Where is it living now? How far north, in what kind of a climate? How much must this wild cat eat? How much prey biomass does the residential puma need at least on its home range, when raising cubs? What have scientists found out now about this?

When studying North America’s puma, we would like to find out: Why has the cave lion been able to live in northern Siberia and Yukon/Alaska, together with the woolly mammoth? In what kind of a climate, and on what kind of a plant-cover has it lived up there? We shall try to find the answer, by first investigating the following questions: How far north is North America’s puma (Felis concolor) living now? In what kind of a climate, and on what kind of a plant-cover is it living there? How much must this cat eat? And how much large prey biomass must there be at least, so that the residential female puma is able to raise her cubs?

How much prey biomass the residential puma needs at least, in order to live there and to raise its cubs, we can best find out, when studying an area, where the density of prey biomass and puma biomass is very high. In other words: If there are many hoofed animals and many pumas, competition for food between these cats will be great. Each puma family must try then to live on as little food as possible. Their grown cubs must leave then their mother’s home range and try to find a new territory for themselves. If there were much food, compared to the number of pumas in a certain area, the grown-up cubs would not have to leave their mother’s home range at all, at least not the female cubs. They would just divide then her territory up among themselves.


Top: Map, where the puma has lived until a hundred, two hundred years ago, before the white man kill him off there (shaded area). And were the puma is still living today in western North America (dark shaded area). Important for us here is, to find out, how far north this large cat has lived in Canada in the past, and how far north it is still living today. From: Kenneth R. Dixon, Mountain lion, in Wildlife of North America (1978:711) Fig. 38.1. - Bottom: Life reconstruction of the puma (Felis concolor). From: A. Turner and M. Antón, The Big Cats (1996) Fig. 3.39.

Biologist Maurice C. Hornocker has studied the puma (mountain lion, cougar) in an area, where the density of large prey animals and of pumas is both quite high. He studied there the predation of the mountain lion on the mule deer and elk: in the Idaho Primitive Area, in the western United States. Maurice G. Hornocker (1970) studied the mountain lion in Central Idaho, south of the Salmon River, from 1964-69, covering 5180 km². Prey animals: bighorn sheep, mule deer, mountain goat, white-tailed deer and moose. Mule deer were most abundant. There were also many elk (wapiti). The study area at the Big Creek and Middle Fork was 518 km² large. All puma cubs left their mother after their second winter. The cubs then leave their territory, become nomads and wander far away, up to 160 km, and more. One old male puma weighed 74 kg. One mature puma in the Big Creek area kills 1 mule deer every 10 to 14 days in winter. In Utah, 1 deer every 10 days.

M. G. Hornocker studied also two puma cubs. He found out: "Two 100-lb (45.3-kg), 17-month-old males raised in semi-captivity as part of this study each consumed 3.5 lb (1.59 kg) of meat, hide, and bone per day during a 28-day feeding trial. At the age of 4.5 months they weighed 35 lb (15.87 kg) and consumed 1.8 lb (0.816 kg) per day during a 15-day period. They were fed all they would eat, after having been weaned at 3 months of age." (1970:26).

The average adult puma in the Idaho Primitive Area, where prey is plentiful, is eating 1.8-2.7 kg meat/day. That is 680-998 kg meat/year. The puma does not eat 30% of the prey. It is waste: the rumen, bones and feet. But small deer are almost entirely eaten. 1 puma has to kill at least 5 to 7 elk (wapiti) or 14 to 20 deer per year. In summer, the heat easily spoils the slain prey. 1 adult puma kills 862-1,293 kg of prey per year.

Puma density

In the 518 km² area in Big Creek and Middle Fork, there are 9 adult residential pumas and 8 juveniles, depending on the residents. 4 adult nomads are for some time in the area. Within this area of 518 km², they must kill 74 to 111 elk or 203 to 305 mule deer per year. That is 12,927-19,368 kg of large prey animals per year. - Will the puma then not kill off all the hoofed animals in this area? – No. The mountain lion population remained stable during 5 years of study. The bighorn population stayed the same. The population of mule deer and elk increased. The average elk weighs 175 kg and the mule deer 64 kg.

Two Puma Cubs: Nutrition

Biologist Maurice C. Hornocker raised 2 male puma cubs in semi-captivity, when weaned at 3 months of age. At the age of 4.5 months, they weighed 15.87 kg and ate 0.816 kg deer biomass/day during a 15-day period. At 17 months of age, each one weighed 45.3 kg. They ate 1.59 kg deer biomass (meat, organs, hide etc.) during a 28-day feeding trial. That is 3.51% of their body weight per day. They were able to eat as much as they wanted.

The meat and organs of the lean white-tailed deer (Odocoileus virginianus) contains 1,890 kcal GE/kg wet weight (Davison, R. P. et al. 1978). The puma digests about 86% of the gross energy (GE) from the deer meat (Ackerman, B. B. 1986). – How much digestible energy have these two puma cubs taken in then per day per kilogram of metabolic weight?

The 4.5-month-old puma cub, weighing 15.87 kg, ate 0.816 kg/day deer biomass during the 15-day period. That is 5.142% of its body weight/day, while semi-captive. It took in then 167 kcal DE/kg0.75 day for growth. - The 17-month-old puma cub, weighing 45.3 kg, ate 1.59 kg deer biomass/day during the 28-day feeding trial. That is 3.510% of its body weight/day. It took in then 148 kcal DE/kg0.75 day for growth.

How large, how heavy

How large is the home range of the female puma in Western North America? And how heavy is there the puma?

The mountain lion in the Diablo Range in California, according to Rick A. Hopkins, San Jose State University, in Cats of the World (1986:223): Female No. 390, 30 kg, 71 km² home range. Female No. 250, 36 kg, in first year 62 km², in second year 70 km².

Kenneth R. Russel (1978), Colorado State University, says about the puma or mountain lion: In western N. America the adult male mountain lion (Felis concolor) generally weighs 63-73 kg, and the adult female 41-50 kg. The home range of the residential female is about 40-80 km², and that of the male 65-90 km².


The free-ranging female puma in the western USA weighs about 45 kg. When non-reproducing, she must kill at least 22 mule deer per year, weighing 46 kg each. She needs then 155 kcal digestible energy per kilogram of metabolic body weight per day. She eats 2.172 kg deer biomass per day. That is 4.827% of her body weight.

When raising 2 cubs, 2 months old, she kills 35 mule deer per year. When killing 9% of the deer biomass on her 66.5 km² home range per year, she needs a lean season prey biomass of hoofed animals of at least 381 kg/km². Any surplus during the rest of the year is irrelevant. The residential puma, raising cubs, disproves the idea, that the large cave lion has lived in the Far North in a severe arctic climate: There would have been too little food. The arctic tundra has only a biomass of hoofed animals of 22 (18-26) kg/km² (reindeer, muskoxen). The puma is not able, to live on the arctic tundra either. 

The puma in Western Canada in winter. From: Canadian Wildlife Service, Cougar, Hinterland Who’s Who (1990) Photo: T.W. Hall.


The Puma of Southern Utah

How much must the free-ranging puma in southern Utah eat per day, when alone and when raising cubs? How much ungulate prey biomass does it need per square kilometer on its home range?

Bruce, B. Ackerman, Wildlife Research, Utah State University, and co-workers (1986) tell us about their "Predictive energetics model for cougars": A predictive model was developed to estimate required energy intake and number of prey animals consumed by free-ranging couguars (Felis concolor). Activity data for input into the model were provided by monitoring 15 radio-transmitted cougars between April 1979 and September 1980.

Study area: Field data were collected on a 4500-km²-study area in south-central Utah: in the Boulder-Escalante area. Climate: January –2.8°C, July 24.5°C. 79% of the ungulate prey was eaten by the couguar. During whole deer feeding trials with 3 captive couguars, in 15 trials with cougars 1-2 years of age, the cougar ate 4.4 kg meat/day. 83% of the biomass, eaten by couguars in Boulder-Escalante consists of ungulates. The rest is small prey, mainly black-tailed jack rabbit (Lepus californicus). Hide, stomach, and intestines of prey were seldom eaten.

There is 1,890 kcal GE/kg wet weight of lean white-tailed deer meat and organs, and 1,530 kcal GE/kg wet weight in the whole snowshoe hare (Lepus americanus). The puma ingests 86% of the gross energy (GE) from the deer, and 80% of GE from small mammals. The average mule deer, killed by cougars on the Boulder-Escalante area, weighs 46 kg.


Total energy requirements (kcal/day) and deer biomass consumed (kg/day) by (a) male and (b) female cougars through time. The lowest curve is that of basal metabolism, to which energy required for activity and growth have been added. From Bruce B. Ackerman, Predictive energetic model for cougars, in: Cats of the World (1986:344) Fig. 2.


Total energy requirements (kcal/day) and deer biomass consumed (kg/day) through time, by a single female cougar, and a female with 1-4 dependent cubs. From: Bruce B. Ackerman, Predictive energetic model for cougars, in: Cats of the World (1986:346) Fig. 3.


Puma with small cubs


Wildlife Monographs, A Publication of The Wildlife Society. Mountain Lion Social Organization in the Idaho Primitive Area. By John C. Seidensticker, Maurice G. Hornocker, Wilbur V. Wiles, and John P. Messick. December 1973 No. 35.


After leaving the kill, there was no immediate further attraction to that proximity. To the contrary, it was our impression that lions made a distinct effort to travel to other parts of their home areas. Occasionally, a lion returned at a later time to a kill site before another kill was made, but by that time scavengers had cleaned up the carcass and the lion did not linger.


Movement patterns of females with small kittens were more complex than those of other classes and varied with the individual lion. Between kills during the first winter, the female left the kittens at protected sites in thickets, bluffs, or under large fir trees or at old kills. Kittens usually were moved each day, but occasionally they were left in the same location for 2 days. Usually, moves were much less than 1.6 km. From these sites, the female made loops out and back, probably hunting. No. 29 was captured with very small kittens (less than 3 months old) near a kill late in 1968, and this female brought her 6-month-old kittens (nos. 47 and 51, a different litter) to kills late in 1970. No. 93 did not bring her 4- to 5-month-old kittens to kills in the fall of 1971, and this same phenomenon had been observed earlier in the study for other females. With one kill, the kittens were nearly 0.8 km away from the site, and No. 93 moved them to a new location even while she was still returning to the kill. … During the second winter until they became independent, kittens were, with one exception, always at the mother’s kill. Seidensticker et al. (1973:29).


Motivated to hunt and to kill, the (mountain) lion must search and find the prey animal in a situation where it can approach undetected to a distance from which a successful attack can be launched. (1973:30)



Number of Locations and Distance from Mother


Distance (km) from Mother

























1.61 +






From J. C. Seidensticker et al (1973:30) Table 19. This shows as, how far the radio-tagged kittens (Nos. 47, 48, 49, 51) were away from their mothers (Nos. 29, 93) in the winter months before the kittens became independent.


6-year-old male puma in south-central Utah. How much prey biomass does the free-ranging residential 6-year-old male puma in south-central Utah need? How much per day and per year? And how much prey biomass must his home range then have?

The free-ranging 6-year-old male puma in south-central Utah weighs 75.249 kg. He needs 6140 kcal GE/d (DE = 86% of GE). He is taking in then 207 kcal DE/kg0.75 day. He eats 4.310 kg deer biomass/day (wet weight). That is 5.728% of his body weight a day. The puma is eating there 79% of the ungulate prey. He must kill then 5.456 kg deer biomass/day, and 1991.44 kg deer biomass per year. That is 43 mule deer, weighing 46 kg each.

I do assume here in this model three things: The puma is killing about 9% of the live prey biomass on his home range in one year (like the other large cats). He is living on a 66.5 km² home range. He is controlling the home range of three residential female. He is taking 1/3 of his food from each one of their home ranges.

His 66.5 km² home range must have then a deer prey biomass of 22,127 kg. 22,127 kg deer : 66.5 km² = 332.732 kg/km². One third of his food, he is taking from the home range of his females. That is 111 kg/km². Important for us is: The 6-year-old male puma, weighing 75 kg, on his 66.5 km² home range, needs a deer prey biomass of at least 333 kg/km².

4-year-old female puma in south-central Utah. The 4-year-old female puma in south-central Utah weighs 45.0 kg, when non-reproducing, and when living out in the wilderness. She needs 3131 kcal GE/day. That is 155 kcal DE/kg0.75 day. She must consume 2.172 kg deer biomass/day: 4.827% of her body weight. That is 1003 kg deer prey/year or 22 mule deer, weighing 46 kg each. When killing 9% of the total deer prey on her 66.5 km² home range per year, there must be 11 144 kg live prey on her home range. It must have then a deer prey biomass of 168 kg/km².


1 female puma with 2 cubs (2 months old). One female puma and 2 cubs (2 months old) need 1,614 kg ungulate prey biomass in one year. She must kill then at least 35 mule deer weighing 46 kg each. When using 9% of the deer prey biomass/year on her 66.5 km² home range, there must be then a total live prey biomass of mule deer of 17,933 kg. That is 270 kg/km². To this we must add the one-third annual food intake of the residential male puma, weighing 75 kg, controlling her home range. This adds up then to a live deer prey biomass of 381 kg/km². The mother puma cannot move far away from her small cubs, when hunting. Her hunting grounds must be then much smaller. She will be able to use then only a very small part of 66.5 km² home range, close to her den. And this small child-bed-range must have then a much larger density of deer. Otherwise, the mother puma will not be able to raise her young ones. From this I do conclude that the lactating puma needs an ungulate prey biomass of at least 381 kg/km². That is why the residential puma, raising cubs, cannot live on the arctic tundra. There is too little food.

The Canadian wildlife biologists R. J. Hudson and F. L. Bunnel (1980:210) found out: The arctic tundra has a biomass (of caribou and muskoxen) of only 18-26 kg/km², or an average 22 kg/km².

1 female puma with 3 cubs (13 months old). The 1 female puma and her 3 cubs (13 months old) do need 5,088 kg live prey/year. When using 9% of the deer biomass per year, there has to be then 56,533 kg live deer biomass : 66.5 km² home range = 850 kg/km² live deer prey biomass. The 6-year-old male puma, controlling the home ranges of three females, is killing 1/3 of his food on her home range. So we must add 111 kg/km². There must be then a deer prey biomass of 961 kg/km² on her 66.5 km² home range.

And if her home range were twice as large, let us say 140 km²? – Then this puma family would still need a deer prey biomass of 404 kg/km². - The 1 residential female puma must kill for herself and her 3 cubs (13 months old) at least 5,088 kg deer biomass in one year. That is 111 mule deer weighing 46 kg each.

1 female puma with 3 cubs (15 months old). The 1 female residential female puma with her three cubs (15 months old) need 5,416 live deer biomass in one year. That is 118 mule deer weighing 46 kg each. I do assume that they are killing 9% of the deer prey biomass on their 66.5 km² home range per year. Their home range must have then a deer prey biomass of at least 905 kg/km². To this we must add 111 kg/km² for the 6-year-old residential male puma, weighing 75 kg. Because he is taking one third of his food from her home range. The female puma and her 3 cubs (15 months old) do need then a prey biomass mule deer of 1,016 kg/km².



Someone might object now and say: But could the residential cougar, raising cubs, no live on the arctic tundra, by killing snowshoe hares and arctic hares, just like the lynx? During some years, when there are many hares, prey biomass must then also be quite high. Would the puma or cougar not be able to find then enough to eat up there? - That is a serious objection. Is it valid?

Bruce B. Ackerman and co-workers (1986:350): "A single adult couguar needs 1-2 black-tailed jackrabbits/day, but it would take 7-8 jackrabbits a day to feed a family group with 3, 15-month-old cubs. The female couguar with cubs could only use small prey, when there is much small prey. The couguar is only able to raise its cubs, where there are enough ungulates. A viable breeding couguar population is only able to exist, where there are enough deer-sized ungulates."

And what would the couguar family, living on hares (rabbits) then do during the years, when most of these hares have died out, when their population density has reached a cyclical low level? Another reason, why the couguar or puma would not be able to live on hares, like the lynx, when raising cubs, is: This large cat would have to use then more energy, while hunting these hares, than it would gain, when eating them. It would have to spend more energy, than it would get out of it.

The cougar or puma clearly disproves the assertion that the much larger cave lion has lived in Alaska and northern Siberia in a severe arctic climate, on an arctic steppe-tundra. The late Pleistocene cave lion was about as large as today’s modern lion and the Amur tiger. The residential lion and puma would starve to death on an arctic plant-cover.

Young male mountain lion with a fawn mule deer in Utah. Photo: F. Lindzey. From: Milan Novak, Wild Furbearer Management and Conservation in North America (1987) Fig. 3.


Puma: Northern-most Range

How far north is North America’s mountain lion, puma or couguar (Felis concolor) living now? In what kind of a climate is it living there?

The map about the puma’s range by Kenneth R. Dixon (1982) shows us: The puma has lived in SW Canada (in the prairies of Alberta to Manitoba) in the recent past up to about 51°N. At the Great Lakes it went up to 48°N. And in eastern Canada (east of the Great Lakes), it went also up to 48°N. In New Brunswick it was living up to 49°N. In our time, the puma is living now in northern British Columbia up to 55-58°N. But I do not know of any proof that the puma is also living at 55-58°N as a resident, raising cubs. It might just live up there as a nomad. In Alberta the puma is found up to 52-55°N.

N. British Columbia, up to 55-58°N: Climate. 4°C mean ann. air temperature. No permafrost. 120-150 days above 5°C per year. 80 days above 10°C. 30 kcal cm² net radiation at earth’s surface. 400-500 mm potential evapotranspiration (P.E.). 1000-2000° 10°C.ts. 14°C mean July temperature.

S. Central Canada, prairie provinces (Alberta-Manitoba), up to 51°N. 4-8°C mean ann. air temp. No permafrost. 150-160 days above 5°C. 135 days above 10°C. 38 kcal cm² net radiation at earth’s surface. 600 mm P.E., 2000° 10°C.ts. 16-18°C mean July temperature.

E. Canada, New Brunswick, up to 40°N. 4°C mean ann. air temp. No permafrost. 150-180 days above 5°C. 120 days above 10°C per year. 40 kcal cm² net radiation at earth’s surface. 600 mm P.E., 1500° 10°C.ts., 18°C mean July temperature.

This proves to me: The residential puma is adapted to a temperate climate, without any permafrost. The puma cannot live in an arctic or subarctic climate, as a resident, raising cubs, because it would not be able to find there enough to eat. Thus, also the much larger cave lion, at the time of the woolly mammoth, could not have lived in an arctic climate. The ungulate prey biomass per square kilometer would have been too low.