lions - biology & behavoir
Lions spend much of their time resting and are inactive for about 20 hours per day. Although lions can be active at any time, their activity generally peaks after dusk with a period of socializing, grooming, and defecating. Intermittent bursts of activity follow through the night hours until dawn, when hunting most often takes place. They spend an average of two hours a day walking and 50 minutes eating.
group organisation
Lions are predatory carnivores who manifest two types of social organization. Some are residents, living in groups, called prides.
The pride usually consists of approximately five or six related females, their cubs of both sexes, and one or two males known as a
coalition who mate with the adult females (although extremely large prides, consisting of up to 30 individuals, have been observed).
The coalition of males associated with a pride usually amounts to two, but may increase to four and decrease again over time. Male cubs
are excluded from their maternal pride when they reach maturity.
The second organizational behaviour is labeled nomads, who range widely and move about sporadically, either singularly or in pairs.
Pairs are more frequent among related males who have been excluded from their birth pride. Note that a lion may switch lifestyles; nomads
may become residents and vice versa. Males have to go through this lifestyle and some never are able to join another pride. A female who
becomes a nomad has much greater difficulty joining a new pride, as the females in a pride are related and reject most attempts by an
unrelated female to join their family group.
The area a pride occupies is called a pride area, whereas that by a nomad is a range. The males associated with a pride tend to stay on
the fringes, patrolling their territory. Why sociality - the most pronounced in any cat species - has developed in lionesses is the
subject of much debate. Increased hunting success appears an obvious reason, but this is less than sure upon examination: coordinated
hunting does allow for more successful predation, but also ensures that non-hunting members reduce per capita caloric intake, however,
some take a role raising cubs, who may be left along for extended periods of time. The health of the hunters is the primary need for the
survival of the pride and they are the first to consume the prey at the site it is taken. Other benefits include possible kin selection
(better to share food with a related lion than with a stranger), protection of the young, maintenance of territory, and individual insurance
against injury and hunger.
Lionesses do the majority of the hunting for their pride, being smaller, swifter and more agile than the males, and unencumbered by the
heavy and conspicuous mane, which causes overheating during exertion. They act as a co-ordinated group in order to stalk and bring down
the prey successfully. However, if nearby the hunt, males have a tendency to dominate the kill once the lionesses have succeeded and
eaten. They are more likely to share with the cubs than with the lionesses, but rarely share food they have killed by themselves.
Smaller prey is eaten at the location of the hunt, thereby being shared among the hunters; when the kill is larger it often is dragged
to the pride area. There is more sharing of larger kills, although pride members often behave aggressively toward each other as each
tries to consume as much food as possible.
Both males and females defend the pride against intruders. Some individual lions consistently lead the defense against intruders, while
others lag behind. Lions tend to assume specific roles in the pride. Those lagging behind may provide other valuable services to the group.
An alternative hypothesis is that there is some reward associated with being a leader who fends off intruders and the rank of lionesses
in the pride is reflected in these responses. The male or males associated with the pride must defend their relationship to the pride
from outside males who attempt to take over the pride. Females form the stable social unit in a pride and do not tolerate outside females;
membership only changes with the births and deaths of lionesses, although some females do leave and become nomadic. Subadult males on the
other hand, must leave the pride when they reach maturity at around 2 - 3 years of age.
hunting & diet
Lions are powerful animals who usually hunt in coordinated groups and stalk their chosen prey. However, they are not particularly
known for their stamina - for instance, a lioness' heart makes up only 0.57 percent of her body weight (a male's is about 0.45 percent
of his body weight), whereas a hyena's heart is close to 1 percent of its body weight. Thus, although lionesses can reach speeds of 59 km/h
(40 mph), they can only do so for short bursts so they have to be close to their prey before starting the attack. They take advantage
of factors that reduce visibility; many kills take place near some form of cover or at night. They sneak up to the victim until they reach
a distance of approximately 30 metres (98 ft) or less. Typically, several female lions work together and encircle the herd from different
points. Once they have closed with a herd, they usually target the closest prey. The attack is short and powerful; they attempt to catch
the victim with a fast rush and final leap. The prey is usually killed by strangulation, which can cause cerebral ischemia or asphyxia
(which results in hypoxemic, or "general," hypoxia). The prey may also be killed by the lion enclosing the animal's mouth and nostrils in
its jaws (which would also result in asphyxia). Smaller prey, though, may simply be killed by a swipe of a lion's paw.
The prey consists mainly of large mammals, with a preference for wildebeest, impalas, zebras, buffalo, and warthogs in Africa and nilgai,
wild boar, and several deer species in India. Many other species are hunted, based on availability. Mainly this will include ungulates
weighing between 50 and 300 kg (110 - 660 lb) such as kudu, hartebeest, gemsbok, and eland. Occasionally, they take relatively small species
such as Thomson's Gazelle or springbok. Lions living near the Namib coast feed extensively on seals. Lions hunting in groups are capable
of taking down most animals, even healthy adults, but they rarely attack very large prey such as buffalo bulls or fully grown male giraffes
due to the danger of injury.
Extensive statistics collected over various studies show that lions normally feed on mammals in the range 190 - 550 kg (420 - 1210 lb).
Wildebeest rank at the top of peferred prey (making nearly half of the lion prey in the Serengeti) followed by zebra. Most adult hippopotamuses,
rhinoceroses, elephants, and smaller gazelles, impala, and other agile antelopes are generally excluded. However giraffes, and buffalos are
often taken in certain regions. (For example in Kruger National Park, giraffes are regularly hunted.) Occasionally hippopotamus is also taken,
but adult rhinoceroses are generally avoided. Even though smaller than 190 kg (420 lb), warthogs are often taken depending on availability.
In some areas, they specialise in hunting atypical prey species; this is the case at the Savuti river, where they prey on elephants.
Park guides in the area reported that the lions, driven by extreme hunger, started taking down baby elephants, and then moved on to adolescents
and, occasionally, fully grown adults during the night when elephants' vision is poor. Lions also attack domestic livestock; in India cattle
contribute significantly to their diet. They are capable of killing other predators such as leopards, cheetahs, hyenas, and wild dogs, though
(unlike most felids) they seldom devour the competitors after killing them. They also scavenge animals either dead from natural causes or
killed by other predators, and keep a constant lookout for circling vultures, being keenly aware that they indicate an animal dead or in
distress. A lion may gorge itself and eat up to 30 kg (66 lb) in one sitting; if it is unable to consume all the kill it will rest for a few
hours before consuming more. On a hot day, the pride may retreat to shade leaving a male or two to stand guard. An adult lioness requires an
average of about 5 kg (11 lb) of meat per day, a male about 7 kg (15.4 lb).
Because lionesses hunt in open spaces where they are easily seen by their prey, cooperative hunting increases the likelihood of a successful
hunt; this is especially true with larger species. Teamwork also enables them to defend their kills more easily against other large predators
such as hyenas, which may be attracted by vultures from kilometers away in open savannas. Lionesses do most of the hunting. In typical hunts,
each lioness has a favored position in the group, either stalking prey on the "wing" then attacking, or moving a smaller distance in the centre
of the group and capturing prey in flight from other lionesses.
Males attached to prides do not usually participate in hunting, except in the case of larger quarry such as giraffe and buffalo. Bachelor
male lions without a pride of their own are forced to hunt. Male lions have also been observed and recorded hunting in groups.
Young lions first display stalking behavior around three months of age, although they do not participate in hunting until they are almost
a year old. They begin to hunt effectively when nearing the age of two.
reproduction
Most lionesses will have reproduced by the time they are four years of age. Lions do not mate at any specific time of year, and the
females are polyestrous. As with other cats, the male lion's penis has spines which point backwards. Upon withdrawal of the penis, the
spines rake the walls of the female's vagina, which may cause ovulation. A lioness may mate with more than one male when she is in heat;
during a mating bout, which could last several days, the couple copulates twenty to forty times a day and are likely to forgo eating. Lions
reproduce very well in captivity.
The average gestation period is around 110 days, the female giving birth to a litter of one to four cubs in a secluded den (which may be
a thicket, a reed-bed, a cave or some other sheltered area) usually away from the rest of the pride. She will often hunt by herself whilst
the cubs are still helpless, staying relatively close to the thicket or den where the cubs are kept. The cubs themselves are born blind -
their eyes do not open until roughly a week after birth. They weigh 1.2 - 2.1 kg (2.6 - 4.6 lb) at birth and are almost helpless, beginning
to crawl a day or two after birth and walking around three weeks of age. The lioness moves her cubs to a new den site several times a month,
carrying them one by one by the nape of the neck, to prevent scent from building up at a single den site and thus avoiding the attention of
predators that may harm the cubs.
Usually, the mother does not integrate herself and her cubs back into the pride until the cubs are six to eight weeks old. However, sometimes
this introduction to pride life occurs earlier, particularly if other lionesses have given birth at about the same time. For instance,
lionesses in a pride often synchronize their reproductive cycles so that they cooperate in the raising and suckling of the young (once the
cubs are past the initial stage of isolation with their mother), who suckle indiscriminately from any or all of the nursing females in the
pride. In addition to greater protection, the synchronization of births also has an advantage in that the cubs end up being roughly the same
size, and thus have an equal chance of survival. If one lioness gives birth to a litter of cubs a couple of months after another lioness, for
instance, then the younger cubs, being much smaller than their older brethren, are usually dominated by larger cubs at mealtimes - consequently,
death by starvation is more common amongst the younger cubs.
In addition to starvation, cubs also face many other dangers, such as predation by jackals, hyenas, leopards, martial eagles and snakes.
Even buffaloes, should they catch the scent of lion cubs, often stampede towards the thicket or den where they are being kept, doing their
best to trample the cubs to death whilst warding off the lioness. Furthermore, when one or more new males oust the previous male(s) associated
with a pride, the conqueror(s) often kill any existing young cubs, perhaps because females do not become fertile and receptive until their
cubs mature or die. All in all, as many as 80 percent of the cubs will die before the age of two.
When first introduced to the rest of the pride, the cubs initially lack confidence when confronted with adult lions other than their mother.
However, they soon begin to immerse themselves in the pride life, playing amongst themselves or attempting to initiate play with the adults.
Lionesses with cubs of their own are more likely to be tolerant of another lioness's cubs than lionesses without cubs. The tolerance of the
male lions towards the cubs varies - sometimes, a male will patiently let the cubs play with his tail or his mane, whereas another may snarl
and bat the cubs away.
Weaning occurs after six to seven months. Male lions reach maturity at about 3 years of age and, at 4 - 5 years of age, are capable of challenging
and displacing the adult male(s) associated with another pride. They begin to age and weaken between 10 and 15 years of age at the latest,
if they have not already been critically injured whilst defending the pride (once ousted from a pride by rival males, male lions rarely manage
a second take-over). This leaves a short window for their own offspring to be born and mature. If they are able to procreate as soon as they
take over a pride, potentially, they may have more offspring reaching maturity before they also are displaced. A lioness often will attempt to
defend her cubs fiercely from a usurping male, but such actions are rarely successful. He usually kills all of the existing cubs who are less than
two years old. A lioness is weaker and much lighter than a male; success is more likely when a group of three or four mothers within a pride join
forces against one male.
Contrary to popular belief, it is not only males that are ousted from their pride to become nomads, although the majority of females certainly
do remain with their birth pride. However, when the pride becomes too large, the next generation of female cubs may be forced to leave to eke
out their own territory. Furthermore, when a new male lion takes over the pride, subadult lions, both male and female, may be evicted. Life is
harsh for a female nomad. Nomadic lionesses rarely manage to raise their cubs to maturity, without the protection of other pride members.
One scientific study reports that both males and females may interact homosexually. Male lions pair-bond for a number of days and initiate
homosexual activity with affectionate nuzzling and caressing, leading to mounting and thrusting. A study found that about 8 percent of mountings
have been observed to occur with other males. Female pairings are held to be fairly common in captivity, but have not been observed in the wild.
« back