Taking A Census: - Page 1: Census Frequency & Methods | 2: Accuracy | 3: What Does A Census Show?
The 1972 countrywide tiger census:
India's countrywide census, carried out in 1972, was a shocker. It revealed the full extent of the reduction in tiger numbers throughout India:
In the area of Coimbatore, where 93 tigers were poisoned in 1874, only four could now be found.
For the famous forests of Rewa, where a 1924 record showed 162 tigers as bagged that year, only 21 were located.
Even in areas like the Sundarbans, where habitat disturbance was at its lowest, experts were able to see that a tiger population previously considered as "abundant" had plummeted to only about 180 cats.
The Maharajah of Bundi had carried out a count of the wild tigers within his state in 1941. The area was small, only about 300 square miles, but at the time there were 75 cats. That area experienced a loss of 94% and only 6 tigers were counted. This was very sobering news considering that the forests here were ideal tiger habitat.
The list went on and on, showing an animal in dire need of protection. It became clear that the at this point tiger numbers had dropped so the entire population was not even as great as the numbers killed in the previous century. That year a total of 2,741 tigers was arrived at. This included Bengal tigers living within Nepal, Bhutan, and a perhaps overly-generous allowance for Bangladesh.
What does a census show?:
Among other things a census shows experts the following:
What a census shows over time:
More important is what trends can be read over time from a number of census results. It is these which show what actions can, and should, be taken to help preserve a species. Then they show how successful the action taken was in producing stability or expansion among a given group.
This page shows the historic census record for Asiatic lions within Gir Forest. No census dating back this far, and this extensive, was available for a tiger group.
The first table shows that the Asiatic lion made a good recovery between 1920 and 1936. After this the numbers fluctuated somewhat, once more plummeting in 1968. From there, and perhaps due to changes in management of the species, a slow but steady increase in numbers can be seen.
The second table reveals that the number of males were slowly increasing, but females were remaining static. Cub levels were good.
This information should not be taken to indicate the Asiatic lion is moving towards recovery. What the charts do not show is that this lion is heavily inbred and even one major illness could eradicate the entire species.
Population of Asiatic Lions (Gir Forest)
|1905||60 to 70|
|1913||Less than 20|
Number of Males/Females/Cubs
With Thanks To Hans Stenström