ecology unit case study: serengeti lion population study

Ecology UnitCase Study: Serengeti Lion Population Study

Panthera leo

“They say that cats have nine lives, but they don’t say that about the Serengeti lion. Life is hard and precarious on this unforgiving landscape”

Warm UpWatch the following and make several observations about lions, their habitat, population, etc. Use terms you have learned about over the last few weeks.• http://ngm.nationalgeographic.com/serengeti-lion/index.html

• http://ngm.nationalgeographic.com/serengeti-lion/index.html#/serengeti

• http://ngm.nationalgeographic.com/serengeti-lion/index.html#/pride

• http://ngm.nationalgeographic.com/serengeti-lion/index.html#/blood-and-bones

Serengeti National Park encompasses 5,700 square miles of grassy plains and woodlands near the northern border of Tanzania.

African Lion Habitat In Decline• http://ngm.nationalgeographic.com/2013/08/

lion-conservation/lion-strongholds

Serengeti Habitat• Serengeti National Park

encompasses 5,700 square miles of grassy plains and woodlands near the northern border of Tanzania.

• The greater ecosystem, within which vast herds of wildebeest, zebra, and gazelle migrate seasonally, following the rains to fresh grass

Serengeti HabitatNowhere else in Africa supports quite such a concentrated abundance of hoofed meat, amid such open landscape, and therefore the Serengeti is a glorious place for lions

Why are grasslands so rich in wildlife?

Serengeti Habitathttp://ngm.nationalgeographic.com/2013/08/serengeti-lions/tracking-prides

Water, Food and Shelter

Population CharacteristicsLife Expectancy:• An adult male lion might

attain the advanced age of 12 in the wild.

• Adult females can live longer, even to 19.

Life expectancy at birth is much lower, for any lion, if you consider the high mortality among cubs, half of which die before age two.

Prides• Tigers are solitary. • Cougars are solitary. • No leopard wants to associate with

a bunch of other leopards. • The lion is the only feline that’s

truly social, living in prides and coalitions, the size and dynamics of which are determined by an intricate balance of evolutionary costs and benefits.

• Why has social behavior, lacking in other cats, become so important in this one?

Live in Family Units…Prides• pride size varies widely,

from just one adult female to as many as 18• prides in the middle

range succeed best at protecting their cubs and maintaining their territorial tenure.

Population CharacteristicsMale Lions• Usually do not stay with Pride• May roam looking to join Prides• May father many cubs and stay• Important for killing large prey • Fight among other male for

“right” to mate and join Pride• What do you think the

characteristics of a successful male lion will be?

Population Characteristics• Males will fight to protect

their cubs• If other male lion become

dominant, it will kill the cubs• Struggle to reproduce is

strong• Male coalitions are gangs,

and if they find a strange male that’s hitting on their ladies, they’ll kill him.

Population CharacteristicsFemales:• pride's primary hunters. • work together to prey upon

antelopes, zebras, wildebeest, and other large animals of the open grasslands.

• Many of these animals are faster than lions, so teamwork pays off.

• Work together to raise young• All related

Population CharacteristicsThe number one cause of death for lions, in an undisturbed environment, is other lions.

• You see a lot of bite wounds on lions, reflecting the competitive struggle for food, territory, reproductive success, sheer survival.

Population Characteristics • 25 percent of cub loss is owed

to infanticide by incoming males.

• Females too, given the chance, will sometimes kill cubs from neighboring prides. They will even kill another adult female if she unwisely wanders into their ambit.

Resources are limited, prides are territorial, and “it’s a tough out there.”

Population Characteristics

Ultimately why lions live in groups…. Holding territory is crucial, and the best territorial locations—hot spots, such as stream confluences, where prey tend to become concentrated—serve as incentive for social cooperation.

Population Characteristics

Other Pride Benefits:• protect offspring• cooperative mothering• females of a pride are

related

• pride of two to six adult females seems to be optimal on the plains.

Lions In DangerOnly 32,000 Lions Remain out of 100,000 Roaming Africa in the 1960s

Africa’s once-thriving savannahs are undergoing massive land-use conversion and burgeoning human population growth.

Lions In Danger

Some 24,000 of the continent’s remaining lions are primarily in 10 strongholds: 4 in East Africa and 6 in southern Africa

Over 6,000 of the remaining lions are in populations of doubtful long-term viability

Lion populations in West and central Africa are the most acutely threatened, with many recent local extinctions, even in nominally protected areas.

Which populations do you think are most vulnerable? Why?

What is the danger posed by all this fragmentation of habitat?

Lions In Danger: Habitat Loss• African savannahs are

defined by the researchers as those areas that receive between 300 and 1500 mm (approximately 11 to 59 inches) of rain annually

• from an original area a third larger than the continental United States, only 25 percent of African Savannahs remains

Lions in Danger: Humans• poaching• retaliatory killing • trophy hunting• Disease• Genetic inbreeding

Interactive Map of Decline

http://animals.nationalgeographic.com/animals/big-cats/lion-decline-map/

Why Are Lions So Important?

• Large carnivores play valuable ecological roles

• crucial for balanced, resilient systems

• powerful cultural and political symbol

• economically critical for many African nations

Dangers of Living Near Lion HabitatWhen people and lions collide, both suffer

For rural Tanzanians the threat of lion attack rises and falls with the phases of the moon, the nocturnal predators favoring the darkest nights. But whether the night is dark or bright, villagers without electricity or plumbing have to walk to the outhouse or to get water and firewood. People have even been attacked inside their homes.

Works Cited• “Serengeti Lions”, National Geographic. August

2013 By David Quammen, Photograph by Michael Nichols (http://ngm.nationalgeographic.com/2013/08/serengeti-lions/quammen-text)

Serengeti Lion Videos

• Photographing Lion With Technology• African Serengeti• Lion Battle Zone

Lion Case Study Quiz

• 5 Short Answers• 5 True or False• 10 points each

Short Answers

1) List 3 benefits lions get from living in Prides.2) List 3 ways humans are causing lion populations to

decline.3) List 3 things (resources) found in the Serengeti that

makes it ideal lion habitat. 4) List 3 reasons why lions are so important.5) Describe how male and female lion behaviors are

different.

True or False

6) Lions in western Africa are doing the best in terms of population size.7) The African Savannah was once larger than the United States. 8) The number one impact humans have on lions is trophy hunting.9) It is common for all the females in a pride to be related to one another.10) A large number or cubs are killed by other lions.