Global IssuesENVIRONMENT-INDIA: Tiger Census Helping Conservation
One year after India released a scientifically prepared census report of tigers in this country, it is being criticised by some as inadequate and acclaimed by others as a significant step towards stemming the rapid depletion of the big cat through poaching and habitat loss.
The 'Status of Tigers, Co-predators, and Prey in India 2008' had concluded that the number of tigers in the country’s protected areas (PAs) in the country ranged between 1,165 - 1,657 animals.
Undertaken by the Wildlife Institute of India (WII), a team of 88,000 forest staff and 50 field biologists, led by Y.V. Jhala, senior faculty member and carnivore biologist, had carried out what was regarded as the biggest such exercise in the world.
The report quantified distribution ranges of the faunal spectrum: bears, wolves, jackals, leopards, wild dogs and ungulates including blue bulls, spotted deer, wild pigs, antelopes and elephants in tiger landscapes.
According to Jhala, GPS mapping of tiger signs in PAs supported by ''camera trapping'' was used to estimate population and density.
'A team of researchers sampled a subset of these areas using robust statistical approaches like mark-recapture and distance sampling to estimate absolute densities of tigers and their prey. Covariate information was generated using remotely sensed data and attribute data using GPS,'' Jhala told IPS in an interview.
More than the scientific assessment of tigers the documentation of its habitat loss was a significant achievement. 'It's a species that readily responds to a little bit of protection to habitat by multiplying,’’ said Rajesh Gopal, secretary of the National Tiger Conservation Authority (NTCA).
‘’Since there is no demand for tiger body parts in our country I will put the habitat loss as the first cause and poaching as second for the animal’s endangered status,’’ Gopal said.
Explaining the methodology Jhala said that ‘’anthropogenic disturbances were obtained at two scales one on the ground in each beat along transects where we quantified signs of tree cutting, lopping of branches, livestock dung, livestock trails etc, and at a lower resolution using remotely sensed data - distance of a forest patch from roads, centers of urbanisation (having electricity- nightlights) etc.’’
Both sets of data when analysed along with tiger occupancy and density have shown that tigers occupy areas where human impacts are minimum and also that high tiger densities are achieved only in areas with low human disturbances'.
'There are only four healthy tiger landscapes in India, which, with ‘inter connectivity and inviolate’ corridors that can offer long term sustenance of the tiger,’’ Jhala said.
'It is up to the state governments to draw action plans based on the conservation recommendations for four [tiger] landscapes,' said P.R. Sinha, director of the WII.
'The landscapes in the north-eastern hills and the Brahmaputra plains currently report tiger occupancy in 4,230 sq km of forests, supporting 200 tigers; forests though fragmented, are connected through the forests of Bhutan,’’ Gopal told IPS.
Gopal said that '20 - 25 corridor linkages for the four identified tiger landscapes have been drawn up based on the conservation recommendations’’.
But despite all the fanfare over the report ‘’nothing on the ground has happened,’’ says Bibhab Thalukdar, secretary general of Aranyak, a wildlife NGO in the Kaziranga Tiger Reserve.
Yet the census has enabled conservators to see both the woods and the trees in the vast sub-continent.
In the southern part of the country the Nagarhole-Madumalai-Bandipur-Waynad corridor hosts 280 tigers across 10,800 sq km and 'serves as a fine example of managing inter-state tiger reserves for establishing populations that have a good chance of long term persistence and provides a source to repopulate neighbouring forests'.
'The voluntary resettlement of people from Nagarhole with positive collaboration between government and non government agencies in the Nagarhole Tiger Reserve must continue to permanently resolve the human wildlife conflict through a win-win solution,' says Praveen Bharghav of Wildlife First in Nagarhole.
'We are now focusing attention on where to deploy the Tiger Protection Force and we have identified the vulnerable source populations of tigers, after the release of the tiger census report,' says Gopal.
Asif Siddique of Hyticos, another NGO working with wildlife says that ‘’by connecting large PAs in the Eastern Ghats with the central Indian PAs a very big tiger landscape would emerge.
Siddique was disappointed that the WII report had overlooked the value of habitat connectivity.
One problem for conservation in central India is the Maoist insurgency in many parts. 'Advisories have been issued to link up wildlife dense corridors and a roadmap has emerged; a time-line has been issued to deliver the tiger conservation plan,' says Gopal.
The Eastern Ghat landscape complex 'constituted by the Srisailam-Nagarjunsagar Tiger Reserve supports an estimated population size of 53 in a single contiguous forest block spread across 15,000 sq km. Insurgency, biotic pressures, and subsistence level poaching of tiger prey' plague conservation.
The report had documented conflict with human populations. 'We now have high resolution spatial data set on where India's tigers are, individual populations, their extent, tiger numbers and connectivity with other populations,'' says Jhala.
'Till 2004, the park's managers believed there were more than 20 tigers, which they reduced to 16-18 in 2004' says the Central Tiger Task Force appointed to investigate the Sariska slaughter of 22 tigers.
Foresters, petrified of suspensions and transfers for admitting depleting tiger numbers, would inflate tiger numbers by relying on the ineffective pugmark method.
'The exaggeration of tiger numbers over the years - the fudging of figures - has meant that the government has been able to avoid reacting to all the other warnings such as organised wildlife crime and the poaching threat, the loss of all the tigers in Sariska,'' says Belinda Wright of the Wildlife Protection Society of India.
The pugmark count, for long the official census method, was severely criticised by scientists like Ullas Karanth of the New York-based Wildlife Conservation Society. 'The pugmark method suffers from its attempt to identify individual tigers with the assistance of experts from the characteristics of the pugmarks,' Jhala.
A skeptical Karanth says of the survey: 'WII scientists have not produced any scientific publication in which their method is fully described. Only some glossy reports are available. So I cannot comment further'.
Karanth's own theory is that the prey base reveals the proportionate numbers of their predators. 'Estimated densities of ungulate prey ranged between 5.3 and 63.8 animals per sq. km. Estimated tiger densities (3.2-16.8 tigers per 100 sq km) were reasonably consistent with model predictions.''
Jhala says that 'there was nothing inherently wrong with the pugmark method. However with advances in modern wildlife science, better techniques are available and should be used'.
'The plaster casts of the right rear foot look different on sandy, loamy soil like on river beds, from that cast on clayey soil in other landscapes. That is the dilemma of park managers' explains Gopal.
Significantly, the census report was criticised, in a peer review, by John Seidensticker, Conservation Biologist of the Smithsonian National Zoological Park and Dr. Ramona Maraj, conservation biologist at the Canadian Department of Environment, Yukon.
'A substantive deficiency we noted in the Framework for Monitoring Tiger Population trends in India is the absence of tiger mortality monitoring. While data remains available in forest guards' records and higher administrative levels, we did not see evidence of incorporation of mortality data into the monitoring protocol. Populations of large carnivores can go extinct in habitats that have abundant food resources'.
Scientists say there are pluses and minuses to different techniques. While the radio collaring method entails major risks for the health and safety of the animals, it tantamounts to zoo keeping and has not been used in the current census.
DNA analysis of scat samples is not considered entirely accurate as the scat can be highly degraded. Besides, this method is expensive.
As for the pugmark method, it is considered obsolete and unscientific. Block counting and mathematical modelling speculates on numbers and discounts anthropogenic conflict, yet it can analyse breeding patterns.
The mark-recapture technique that has been used in the current census cannot indicate inbreeding and high feline mortality.
Since submission of the report: - All tiger reserves have been declared as critical tiger habitat that enables speedy relocation of all people living in PAs. - Eight new tiger reserves are being notified. - The relocation of tribals has commenced in the Mudumulai Tiger Reserve. - Biodiversity committees have been entrusted with identifying flora and fauna to document peoples’ interdependence on forest ecosystems in conformance with the Forest Rights Act.
© Inter Press Service (2009) — All Rights ReservedOriginal source: Inter Press Service