Cheetahs: Endangered species
Gulamabbas Muhammedali
Sunday News; Sunday,August 13, 2006 @00:02
GULAMABBAS poses with a cheetah
CHEETAHS were originally found from Cape of Good Hope to the Mediterranean, throughout the Arabian Peninsula to the Southern part of the former Soviet Union.
Population numbers have declined from more than 100,000 in 1900 to approximately 9,000 to 12,000 today of free-ranging cheetahs in Africa.
Decreasing numbers are a result of a declining in cheetahís habitat and prey base as well as conflicts with people. As humans convert more of the cheetahís habitat into farmland for livestock production, human and cheetah conflicts have emerged.
Cheetah parks and reserves have led to direct competition with lions and hyenas which may take up to 50 per cent of the cheetahsí kills and which kill a high percentage of cheetah cubs. Rainfall also may influence cheetah cub survival through effects on prey density.
Historically, the cheetah has been viewed as a pest and threat to the livelihood of livestock farmers, and it is legal in Namibia to shoot an animal that interferes with on’ís property and livelihood.
Cheetah lacks genetic diversity rendering it less adaptable to environmental change and challenges. The cheetah’s genetic uniformity may increase susceptibility to infectious diseases and pose another threat to population viability. Disease risks include Feline Infectious Peritonitis (FIP) and anthrax. Canine Distemper Virus (CDV) is a potential catastrophic threat. Rabies may be a periodic threat as exposure and immunity shift through time. Feline Immunodeficiency Virus (FIV) is a potential long-term disease threat.
The gestation period is about 90 days. Cheetahs that lose litters usually breed again within 3 weeks (young animals may be delayed for 3 months). Animals can breed throughout adult life. Cheetahs can live more than 15 years but reproduction appears to cease by age 10 to 11 in the wild, and few animals live beyond this age.
Cub survival (0 to 1 year age class) is highly variable among wild felid populations. Additionally, the factors affecting this variability may differ in importance among populations and at different times in the same population. Factors that have been identified in cheetahs include changes in prey availability, diseases, and predation.
Survival of sub adult (1 to 3 years for females and 1 to 5 years for males) and adult (3 years and older for females and 5 years or older for males) is strongly related to human influences, especially hunting and killing of nuisance cheetahs on private lands.
The natural mortality rate may range from 5 to 10 per cent but total annual mortality could range up to 30 per cent with removals on the farmlands.
Drought combined with a disease induces decline in a prey population and increased cheetah removals by farmers.
The average surviving cheetah population size project to 100 years, starting from 2,500 animals (with 40 per cent+10 per cent of females not producing a litter each year), declines when adult female average annual mortality is 20 per cent or greater for all values of catastrophe severity and frequency. If no catastrophe events are included, populations can sustain about 20-25 per cent female mortality and maintain a positive growth rate. Addition of any catastrophes at an average frequency of 5 per cent (once in 20 years) reduces the sustainable level of annual female mortality to less than 25 per cent. The risk of extinction over 100 years rises rapidly when these mortality rates are exceeded.
Variations of mortality rates up to double those of female mortality rates had no effect on the population size. Thus management of adult female mortality rates is critical for managing population size through management of population growth rates.
Increasing the population size delays the median time to extinction under any given scenario. Thus larger population sizes potentially have a longer time and greater capacity to recover from periods of increased mortality whether due to climatic factors, loss of prey, and reduction in carrying capacity or human induced mortality.
For a population size of approximately 2,500 animals this would be about 60 to 70 adult females per year. This would provide a margin of safety for uncertainties in estimates of density, uncertainties in knowledge of natural female mortality rates, in female reproduction rates, in directions and rates of migration, and in estimates of fluctuations in natural mortality.
Removal of males needs to continue to be given preference over the removal of females in the control of problem animals in the farmland population.
Population viability and growth rates are not as sensitive to male mortality rates over a wide range. Total annual adult male mortality rate of 30-35 per cent will have no effect on population growth rates.
While at the outskirts of Masai-Mara, a cheetah and her three cubs were resting on the grassland. A male lion appears, and the mother gets worried about her cubs. The cubs had already felt the presence of the lion. They hide themselves without any movement. The cheetah moved to a distance away from the cubs and started distracting the lion. The lion started to chase the cheetah but failed to catch up with its speed, and gave up ultimately. The cheetah returned back to the cubs and by calling them one by one appeared from the bush and all moved away happily.