User:Kosigrim/L-age

Lions’ age



Population
Lions (Panthera leo) are the only social cat species characterized to date  with remarkably egalitarian female behavior and unique voluntary system of communal cub rearing. Their populations appear to be sensitive and in accelerating decline due to several factors such as reproductive output (pregnancy rate), delayed maturity, lower survival, competition for food, incidence of infectious disease and overall human activity (including revenge or trophy hunting). Few carnivores have suffered more dramatic reductions of range and population sizes than the lion. Before humans colonized the Western Hemisphere, the lion was perhaps the most widespread terrestrial mammal, ranging from southern Africa to northern Europe, across all of Asia and North America, extending south as far as Peru. It has been show that the lions' population at Ngorongoro Crater can be seriously endangered by infectious disease even with a large stable food supply and no real threats from competing species. Old population models have assumed that population trends could be predicted from data on survival and reproduction of lions. However, a more complete understanding of population dynamics can only be achieved by taking into account the impact of social and family structure on the population as a whole.

Trophy hunting
Lions are generally perceived by Africans as having a negative value, but trophy (tourist) hunting is a management tool that can provide positive economic value to local people. For example, in 1992, trophy hunting in the Selous Game Reserve generated 1.28 million dollars for the Tanzanian government, of which 0·96 million dollars were returned to wildlife conservation. Lions' hunting industry has always been based on arbitrary quota system that is difficult to enforce. There is low risk of setting excessive trophy hunting quotas in areas where it is possible to estimate the lions' population size. A simulation model suggested that quotas could become inappropriate to the conservation of lions. Lions' breeding biology and social behaviour (such as infanticide ) could inform a threshold-age criterion that would minimize the adverse effects from killing of sexually mature males. Young adult males should be excluded from trophy hunting so females would be seasonably impregnated and vulnerable offspring be protected by their fathers.

Maturity
Lions' reproduction can take place in any month of the year; gestation is 110 days, and the interbirth interval is about 2 years. Male lions reach maturity at about 2.5 years of age and live to a maximum of ~15 years in the wild. The lion’s mane reaches full size at about 4 years, and peak reproductive ability is effectuated by ~8 years.

Nose indicator
The most consistent age indicator for the Serengeti/Ngorongoro lions is the amount of dark pigmentation in the tip of the nose, which becomes progressively freckled with age. Lions’ noses continue to darken until they become 9 years old, while individual variation of the darkening could be observed. For example, the noses of 5 years old males are 50% black (see example on the right).