Lion - biology.

Lion - biology. I INTRODUCTION Lion, one of the largest members of the cat family. The lion's size and strength have captured human imagination since ancient times, giving these animals the nickname king of beasts. Lions are also known for their mighty roar, a fearsome sound that can be heard by humans more than 8 km (5 mi) away. Lions once ranged over vast areas on many continents. Fossil evidence shows that until about 10,000 years ago, lions lived throughout Africa, Europe, the Middle East, and into Asia as far as southern India and the island of Sri Lanka. They also lived in North America and northern South America. Since then, however, the lion's range has been shrinking steadily. Human hunters have killed countless numbers of lions as well as the hoofed mammals that lions eat. In many places, people have taken over the lion's habitats, which often are good places to farm and raise cattle. These habitats include grassy plains, savannas, and dry woodlands but never thick forests or jungle. Today, lions are found in the wild in only two places on earth. About 100,000 lions survive in Africa south of the Sahara Desert. Another 300 lions, called Asian lions, live in a reserve called the G?r National Park and Lion Sanctuary in northwest India. In both places, lions continue to be threatened by human activities. Thousands of lions also live in zoos and circuses around the world. II PHYSICAL CHARACTERISTICS Lions rival tigers for the title of biggest cat. In fact, lions and tigers are so similar in their physical features that without their distinctively colored fur, even scientists have trouble telling them apart. Male lions weigh between 150 and 250 kg (330 and 550 lb) and stand about 123 cm (about 48 in) tall at the shoulder. They measure up to 250 cm (98 in) in length, not including the tail, which measures an additional 90 to 105 cm (35 to 41 in). Female lions are smaller, weighing between 120 and 182 kg (265 and 400 lb). They stand about 107 cm (about 42 in) tall and measure less than 175 cm (less than 69 in) in length, with a slightly shorter tail. Lions have massive shoulders and strong forelimbs, long, sharp claws, and short, powerful jaws. As carnivores, feeding entirely on the flesh of other mammals, lions have 30 teeth, including large piercing canines to grab and kill prey, scissorlike molars to slice into flesh, and small incisors to scrape meat from bones. Adult lions have fur that varies in color from light tan to reddish brown. The tufted tail is tipped in darker fur. Only male lions grow a mane around the shoulders, which grows darker and fuller as the animal ages. Cubs are born with thickly spotted fur, which helps them hide from predators in brush and clumps of vegetation. The spots gradually fade as the cubs grow up, sometimes remaining on the legs and belly until the lion reaches adulthood. African lions and Asian lions differ slightly in appearance. Asian lions have a flap of skin on the abdomen, called a belly fold, not found in African lions. Male African lions have fuller manes than Asian lions do, and the shape of their skulls differs slightly. Despite their immense strength, lions do not have an easy life in the wild. They suffer from parasites and disease, they get injured or even killed while hunting or fighting with each other, and they may starve when food is scarce. About two-thirds of all cubs die before they are 1 year old. Adult males are usually old and battered by age 10, if they survive that long, and they rarely live longer than 12 years. Females may live longer, up to 16 years, and some are still breeding at 15. In zoos, where they receive veterinary care and plenty of food--and are not allowed to fight--lions can live as long as 25 years. III SOCIAL BEHAVIOR AND REPRODUCTION Lions are unusual among cats for their habit of living in groups. A pride consists of 2 to 12 adult females and their cubs. All of the females are related: sisters, mothers, aunts, and cousins. Born into a pride, a female will stay in it for life, although a large pride may split into smaller ones. Pride females care for cubs together, hunt and eat together, and aggressively defend their hunting grounds and water holes from other prides. Equally important, pride females must often defend their cubs from groups of males. Unlike females, male cubs are driven from the pride when they are between two and four years old. If they are lucky, they leave with brothers and cousins; if not, they team up with unrelated males. These groups of two to six males are called coalitions. The goal of a coalition is to join a pride of females to mate and have young. This usually involves chasing off the coalition currently in residence with a pride, although resident males do not leave willingly. Bloody combat may take place, with the larger of the competing coalitions generally winning the pride. These periods of change spell trouble for pride females and their young. When new males take over, they try to kill the cubs, which were fathered by males in the ousted coalition. Statistics show that invading male lions kill as many as one-quarter of all lion cubs. When a female loses her cubs, she is willing to mate sooner with the new males. However, females vigorously try to defend their cubs. One on one, a female lion is no match for a much larger male lion. But by fighting together, pride females are sometimes able to save their cubs. These violent exchanges of male ownership of a pride take place every two to four years. Between these exchanges, social relations between males, females, and young are fairly peaceful. Lions spend long days sleeping, for up to 20 hours. Social bonds between pride members are reinforced with contact behaviors such as cheek rubbing and with vocalizations. When a female lion is in estrus, a recurring state in which the female is receptive to sexual activity, she mates repeatedly with all of the coalition males. After a gestation of 110 days, she gives birth to one to four young in a secluded place away from the group. The mother introduces the cubs to the pride when they are about eight weeks old. Very often, several females give birth at about the same time, and they share the duties of protecting and nursing the cubs. Mothers nurse for up to 8 months, although they begin to take cubs to eat at animal kills when they are as young as 3 months old. At about 11 months of age, cubs start learning to hunt with the pride. It will take several years of practice before the young lions become accomplished hunters. Females take care of their young until they are about two, when the mother is ready to produce a new litter. With no direct role in cub care, male lions, when they are not sleeping, patrol the boundaries of their large territory, leaving scent marks of urine and other secretions that warn off intruders. Males in a coalition roar together to signal their strength, to proclaim ownership of a territory, and to intimidate potential rival coalitions. Males try to maintain ownership of their pride as long as possible, because males without prides are males that do not live very long. IV HUNTING Living with a pride is important for male lions because they typically feed on the kills made by the females. Lions are powerful hunters, but depending on the prey, they make a kill only once in about every five attempts. Often, lions scavenge, or steal prey, from other carnivores, such as hyenas. For all members of a pride, feeding is a free-for-all. The big males eat first followed by the females, who compete among themselves, no matter which female or females actually made the kill. Cubs receive no special treatment and eat last. Lions usually hunt at night, alone, or in groups. Their preferred prey are large hoofed mammals, such as zebras and wildebeests, but they will go after small hares as well as huge giraffes. Typically, a lion hunting alone will slowly and silently stalk its prospective victim, trying not to be seen, until it is about 30 m (about 98 ft) away. Then with a burst of speed, the lion will run toward the prey, grab it, and throw it to the ground. The lion kills the prey by biting the back of the animal's neck with sharp canine teeth or by holding the prey's throat in its jaws until the animal suffocates. If, during a hunt, the prey detects the lion's presence and starts to run, the lion gives up. Although lions are capable of high speed over short distances, they do not have the endurance to chase down an escaping animal. In group hunts, lions may surround potential prey so it has nowhere to escape, or some lions may drive prey into the reach of others. Two or more lions may grab and slash together to bring down an animal. Lions are more likely to hunt together to kill larger animals, such as zebras and buffalo, and usually hunt alone to kill smaller prey, such as warthogs. In either case, other lions that did not help with the kill still move in to share the food. When feeding on a large kill, a lion can eat almost 36 kg (almost 80 lb) of meat in one feeding and then not need to eat for several days. On average, a lion needs to eat about 5 kg (about 11 lb) of meat daily. How often it must hunt depends on the size of the prey it kills--or on the amount it can scavenge from others' kills. In zoos, lions are fed 1.5 to 4 kg (3 to 9 lb) of meat per day. This is less than they would eat in the wild due to their less active lifestyle. Scientific classification: The lion is a member of the cat family, Felidae, in the carnivore order, Carnivora, and is classified as Panthera leo. Contributed By: John Seidensticker Susan Lumpkin Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.