 |
Trophic Level IV: Large Carnivores |
 |
|
Trophic Level IV: Large Carnivores |
|
Panthera leo
Length: 158-192 cm (62-76") female, 172-250 cm (68-98") male
Height: 100-128 cm (39-50")
Tail: 60-100 cm (24-39")
Weight: 122-182 kg (269-400 lb.) female, 150-260 kg (330-574 lb.) male
Status: Not considered endangered but its range is being reduced and it may soon survive only in game parks and protected areas.
Some local populations, once considered sub-species, such as the Indian lion, are endangered.
Habitat: Lions were once found in almost all habitats across Africa except the driest deserts and extensive areas of rainforest. Today, they are confined to parks, preserves and game reserves which tend to be grasslands, wooded grasslands or woodlands.
Food: Most of the prey species
of the lion weigh between 50 kilograms (110 pounds) (Thomson's gazelle-sized prey) and 300
kilograms (660 pounds) (wildebeest or zebra-sized prey). During those periods when normal
prey-species are absent, lions will eat smaller animals (i.e. 15 kilograms/ 33 lb.) or
larger ones (1 000 kilograms/ 2,200 lb.).
As a rule, the very large and the very small are not preferred. A hare does not make much of a meal for a lion. An elephant, giraffe or buffalo presents a real threat. These larger animals are generally hunted by prides that tend to specialize in hunting larger prey.
Lions usually stalk their prey. Their best chance of making a kill is when they are within 30 meters (90 feet) of their victim and their victim is looking away. They normally kill wildebeest-sized prey by strangulation. They either bite its neck and crush its jugular so that it cannot breath or they cover the victim’s mouth and nostrils with their mouths.
Bring Home the Bacon
Small prey are dispatched with a single bite.
Large prey such as buffalo, giraffe and elephant are brought to a state of shock by causing the animal to lose blood. Eventually, the animal no longer fights and the lions begin to feed. In the case of an elephant, the animal may linger for one or two hours (or more) before dying.
At a kill, there is much fighting and growling. It is a case of every lion for itself. If there is not much food, then any males present may get most of it. Dominant lionesses get more than subordinate lionesses. Cubs are lowest and must wait for others to feed.
Lions are aggressive at a kill. It is something they learn early. Even a lion cub will snarl and bat at a dominant male.
Social System: Lions
live in prides. A pride consists of a core group of lionesses that live in the same area
for several years. This territory is passed
onto their female descendants and may last for years or even decades. When lions of the
same pride greet each other, they rub heads and sniff each other. They also lean on one
another. Head rubbing mixes their scent with the scent of the other lions in the group.
The heart of the pride are these females. They keep it safe from the intrusions of other lionesses. They last as males come and go. Young females stay with their mother's pride or leave as a group once they reach sexual maturity to form a pride near their mother's home range.
A male leaves the pride when he is between two and three years old. As his mane grows, he becomes more of a threat to his father and is chased out. If he is lucky, he will leave with a cohort (a group of similarly aged lions) that may or may not include his brothers.
Travels of a Nomad
Alone or in a cohort, he must make his way through a maze of territories occupied by adult males. They will kill him if they catch him. Forced to eke out an existence on the edges of territories or in poor regions where no other lions go, they face a life of struggle. In the Serengeti-Mara, many of these wandering males leave the safety of the park and move into areas where there is agriculture or hunting. Life tends to be short in those places for a large predator. Tanzania still allows sport hunting. Kenya does not. Illegal hunting (poaching) is rampant in both countries.
Nomadic lions in the Serengeti-Mara do have an advantage over males in other locations. They can follow other lions or the migrating herds of zebra and wildebeest as they move through the territories. In areas, such as Ngorongoro Crater, where herds do not migrate, nomadic lions face a much tougher life. Often, the resident territorial males force these nomads to leave the crater.
A typical male-coalition (or male cohort group) is made up of two or three males. Sometimes there will be four. There is a report of one such group having eight adult males but these super-groups are extremely rare.
By the time they are five or six years old, the male lions make increasingly frequent ventures into the established territories patrolled by resident males. They roar out their challenges and wait for the response. A lion’s roar will carry for 8 kilometers (5 miles) on a still night. If the roars from the resident males indicate strength then the interlopers will retreat. Sooner or later they find a weakness. Perhaps one of the resident males is away leaving his "friend" alone. Perhaps there is only one male in the territory to begin with.
Making a Territory a Home
The nomads must challenge and fight the resident pride male. If they defeat the resident male, they lay claim to the pride's females.
They have, at most, two or three years to breed and sire their own young. During that time they must constantly defend their rights as other nomads seek them out. There is no second chance for the loser.
Where lion populations are high, a single male has little hope of ever becoming a pride male. Coalitions of four or more may hold a territory for up to four years.
Females with nursing cubs will not mate. The production of milk acts as a form of birth control. Since the males have only a short time to father their own offspring, they hunt down the young cubs and systematically kill them. It is genetically pointless for them to waste their access to females that are raising the young of the male(s) they just defeated or killed.
A few weeks after the death of her cubs, the lioness comes into heat again. She mates frequently with the male during her period of heat. She will not conceive yet. She will come into heat once a month for three or four months before she will become pregnant. It has been estimated that lions mate 3,000 times for every cub that reaches one year of age! Lions mate a little over twice an hour during the female’s peak estrus. Coalition males do not fight over females. When one male tires, the other takes over.
And Baby
Makes…
These monthly mating periods help forge bonds between the lioness and the lion. It also allows the pride to stabilize. Sometimes the new males will not be able to hold a territory for more than a few weeks.
The frequent matings also serve to lower the male's aggressiveness towards cubs. When his cubs are born, he is content to leave them be. In fact, he becomes their protector. He is often more tolerant of the cubs’ antics than the females are. Perhaps more importantly, he may allow a cub to feed beside him, something females are less likely to do.
Because all of the lionesses in the pride lose their cubs at about the same time, they all come into heat around the same time. This means that cubs are often born to several females within the pride within a short span of time. Gestation period is 14 to 15 weeks.
Survival of Cubs
As long as the pride remains intact, with the same males, a lioness will give birth every 20 to 30 months. Three to four cubs make up the average litter. Cubs are born in a thicket or other secluded place well away from the pride. Cubs weigh between 1 and 2 kilograms (2 to 4.5 pounds) at birth. Their eyes open anywhere from three to eleven days later. They will stay hidden for one to two months. During this period of time, their mother makes frequent trips away from the den to hunt. Should spotted hyenas or leopards discover them while she is away, they will be killed.
By the time they are seven weeks old they can keep up with the pride.
When they are seven to ten months old, they are fully weaned. A mother will not wait for a cub after it is seven months old. If it can't keep up, it dies. In the Serengeti-Mara, over 50 % of the cubs die before they are a year old.
Females breed when they are four years old.
Nomadic Single
Females, Lost in Space
Single female lionesses are not an uncommon sight on the Serengeti plains. Although most females stay with the pride they were born into, it can happen that a lioness finds herself alone and pride-less. The arrival of a new pride male may cause young females to flee for their lives. Disease or accidents may kill other females with which the single lioness associated. A battle with a neighboring pride of females may also result in a female being isolated.
Such lone females have little hope of long term survival. A passing male, even a male with a pride, may mate with her. The chances of her successfully raising her cubs is slim. She will need a lot of luck to provide them with enough food. One such female succeeded in raising only one cub past the age of two in a period of ten years. That cub was, unfortunately for her, a male. He left his mother. Had it been a female, the mother and daughter might have been able to establish a pride.
Why Prides?
Why live in prides? Leopards don't; nor do cheetahs. One of the main advantages gained by numbers of predators living in groups is that it allows them to take down larger prey than one or two could on their own (see Wild Dogs or Hyenas). But lions seldom take down prey much larger than themselves. A single lion can bring down an adult zebra or wildebeest. It takes several lions to tackle prey the size of buffalo or elephants. While the Serengeti-Mara ecosystem supports some of the largest prides ever seen, such hunts are rare, especially involving elephants.
Two lionesses hunting together are twice as successful as one hunting alone. Two seems to be the ideal number but in the Serengeti-Mara, most females live in prides of three or more. Even in these larger prides, a great number of observed hunts involved one or two animals at the most. Others joined in feeding on the kill after it was made.
It also appears that not all lionesses hunt often. One will take an interest in a prey species and slink off to hunt while her pride members continue to doze. If the hunt fails, she will return, rub heads, and then flop down and go to sleep.
Hunts do not seem to be well planned either. When a group of lions goes hunting together, the success of their hunt usually depends on how quickly one cat reacts to another's success. If only one succeeds, for example, in leaping on a buffalo's back, the prey still has a good chance of successfully fighting off the lion. That changes if other members react quickly enough and arrive in time to assist the first lion.
The Truth About Cats and Dogs
Contrary to popular belief, lions do not roar to start stampedes or show themselves to distract prey's attention from the ambush that has been laid. Nor do they always hunt into the wind so that the prey cannot smell them. Lions seem to pay little attention to the wind.
(Author’s note: Regarding prey scenting lions; I have not found much published research on this but from my own observations in Ngorongoro, the Serengeti and the Mara, it seems to me that prey cannot help but smell lions. Indeed, lions clearly mark their territories and leave their scat everywhere. I suspect that to a prey's nostrils, the scent of lion is so common that it may actually be ignored. Certainly, this must be the case near fresh water sources where the lions just sit and wait for the wildebeest to come for their daily drink.)
When prey is abundant, such as when the great herds are in their territory, no animal goes hungry. How can you miss when you have 1.5 million wildebeest and a quarter of a million zebra to select from? However, when the great herds are gone, research has shown that single lionesses and large prides are the most successful at attaining food.
Warthogs are resident year round and a single lioness (or lion) can make do nicely with one pig every few days. A large pride cannot survive on warthogs. They are able to bring down resident buffalo, something one or two lionesses dare not attack.
Pride Hath Its Advantages
A single lioness has little hope of defending a large kill against spotted hyenas or two or more lionesses from another pride. Invariably, the kill is lost. A pride can usually defend its kill against spotted hyenas or another group of lions. The outcome depends on several factors. How many lionesses are there? How many hyenas? How aggressive or hungry are the killers and the scavengers?
The presence of a single male lion virtually guarantees that hyenas will not steal a kill. If two prides of females are fighting over a kill, the male usually remains aloof from the conflict.
There seems to be little advantage, in terms of food, to explain the existence of prides. There is a compelling reason for prides to exist. First, communal living allows for the raising of cubs. A female can be off hunting while her cubs are under the protection of other lionesses. Social benefits are important.
However, the successful rearing of cubs is directly related to the quality of the territory a pride is able to defend. Large numbers of allied lionesses allow the pride to protect a territory.
A Tale of Three Prides
The fate of a pride varies. In 1966, George Schaller studied three prides all living along the Seronera River. He named them the Masai, Seronera and Loliondo prides. Their history has been well documented for over thirty years since that time.
In 1994, the Masai pride still could be found in the northern part of their original range. Two new prides have been established by daughters of the lionesses Schaller studied. They are known as the Masai Kopje and Sametu prides. Between them, they occupy the territory that the parent pride did in 1966.
The Seronera pride went through a long period of division. By 1978, the original pride had split into three small prides and two single, independent females. When the small prides fell to fewer than three lionesses, they were attacked by other prides living along their borders. By 1994, there were no female descendants of the Seronera pride left.
The Loliondo pride faired best of all. Large numbers of female cubs were raised
successfully. Some of these remained with their mothers while others established five new
prides, acquiring in the process most of the territory
once occupied by the Seronera pride.
Behavior: Lions are the Serengeti-Mara's most successful cat for several reasons. Wherever they live, they are able to survive with the prey that is available. Lions in the Serengeti-Mara make do with warthogs, Thomson's gazelle and buffalo when the herds are gone. In Savute, Botswana, they feed on teenaged elephants when the herds of zebra are not available.
In tough times, many cubs will die but the adults survive. They are large and can starve for several days before being seriously affected. In really tough times, the pride can break down entirely. A single lion will trek for days to find food. When the good times return, the cat goes back to its old haunts and renews its social ties. Throughout their range, lions are five to ten times more abundant than the solitary cats: leopards, cheetahs and tigers.(Author’s note: There are no tigers in Africa today. At one time, several thousand years ago, there were tiger species found on this continent but they are all extinct now.)
A large pride of lions living in a place like the Serengeti can keep its worst enemy, another large pride of lions, at bay and out of their territory. They advertise their ownership by roaring and scent marking their land. Males do this to keep other males out while females do it to keep other lionesses out.
Predators: Lions are at the top of their food pyramid. Hyenas may occasionally attack and kill an isolated lion. Eagles and other predators will kill cubs but these events are rare. Humans are the lions’ main enemy. Lions probably kill more lions than do all other predators, except humans.
Flies on Them
The long term studies of lions in the Serengeti and Ngorongoro have illustrated clearly the relationship between abiotic and biotic factors. One of the more startling studies concerned Ngorongoro's lions, flies and rains. In 1961, the "short rains" arrived late in Ngorongoro Crater. Usually, they arrive in November and December and are then followed by a two month dry spell. That year, there was no dry spell and the rains continued through until the "long rains" arrived in March. The rains were unusually heavy and lasted until May.
A fly, Stomoxyx calcitranus, lays its eggs in the crater's soil. The damp conditions were perfect for its breeding cycle and huge numbers of flies resulted. This species looks like an ordinary house fly but bites like a tsetse fly. A swarm of these flies can bleed a large mammal to death in a few days. A few Maasai cattle and one eland did die of their bites.
However, the flies, for some reason, found the crater's lions to their liking. They tormented them relentlessly. The lions were covered with flies. They were so distracted by the flies that their hunting became disrupted. Instead, they sought shelter from the hordes by escaping into trees or hiding in spotted hyena burrows. Many lions became emaciated and covered with sores.
By the time the scourge ended, the crater's lion population had dropped from 70 animals to seven females and one male. An additional eight males entered the crater after the plague. There were no resident male coalitions to oppose them. Since then, no other outside males have succeeded in making inroads into the crater.
Under normal conditions, the population would have continued to grow with the immigration of new lions from the plains surrounding the crater. However, few, if any, lions were able to safely make the crossing from Serengeti National Park into the crater. The plains between the park and the crater were occupied by Maasai herds and lions were not tolerated. Lions outside the park's protection do not survive long.
The Magnificent Ten
Isolated from other lions, the crater's surviving females bred. There were four adult lionesses and they successfully raised three sets of young. Virtually all lions in the crater are today descended from these four females. Their daughters and granddaughters established five of the crater's six established prides. Their sons and grandsons became the ruling males, successfully deterring any outside males lucky enough to make their way to the crater.
Normally, lions will not breed with close relatives but these lions had no choice. In-breeding resulted and the effects of it are only now being discovered. These include low sperm counts and deformed sperm. Lower fertility is also being seen.
None of this is obvious to the tourist visitor. Lions are more abundant in Ngorongoro Crater than they are in the Serengeti. They are also somewhat larger. Some say they are not as good looking. (I saw little difference.)
Still, the research points out just how vulnerable isolated populations can be to unsuspected threats such as prolonged rains and flies.
Facts and Figures for Comparison: Lion / Crocodile / Human
The chart below compares the food requirements of three of the top predators in the Serengeti. All figures are approximate. Food can be considered in three different ways. Food can be thought of as the number of kilojoules (calories) needed to keep an animal healthy. It may also be thought of as the weight or mass an animal needs to consume. Food may also be seen as the animals a predator must eat. The food requirements for lions are broken down in these three ways.
Food Requirements of a Lion
Food Requirements of a Human
1 average student = 50 kg (110 lb.)
Another way of looking at a lion’s needs can be seen if it is shown as a food pyramid.
1 lion
Ý
238 Thomson’s Gazelles
(7 times the lion's mass)
Ý
2.6 square kilometers (1 sq. mile) of grass*
*1 sq. meter (1 square yd) of grass
produces
0.5 kilograms (1 lb.) of edible material a month = 577 tonnes/kilometer square/month
(1500 tons/sq. mile/month) = 9 x gazelle’s mass Serengeti biomass of 26 herbivores 1,000,000,000 lb.
(see also: Appendix IV: Comparison of
Average Density of Lions, Spotted hyenas & Prey in Ngorongoro and the Serengeti) 
Select a Page:
1 2
3 4 5 6 7 8 9 10
CDROM Index | Title Page | Contents | Index | Glossary | Bibliography | Appendices | LifeStories Online
Dave Taylor's African Safari - Book 5: Trophic
Level IV: Large Carnivores (Standard
Version)
Copyright © 1999 Dave Taylor & James Cash