Tiger Census in India (Summer 1972)

1. What they did

The author, a forest officer from Orissa, explains why India needed a tiger census and how the first country-wide census was run in the summer of 1972. Tigers had been declining for two decades. Signs of tigers were becoming rare in former strongholds, and in Phulbani district of Orissa the count fell from 46 tigers in the 1966 census to 8 in this one. He argues that the oft-quoted figure of 40,000 tigers in the past could never have been supported by the available prey and land.

Tigers are elusive and cannot be counted by sighting. Automatic camera trip photography works only in small study areas because of the cost, and counting tigers at baits (as in the 1968 lion census in the Gir) was, in his view, expensive and unreliable. Instead he proposes the “Co-operation Tiger Census”, which he first used in Orissa in 1966:

• Many trained people at once. Each forest guard searches a small counting unit (a beat of no more than 15 to 20 km²) for signs of tigers during the same week, and records them in space and time.
• Pugmarks above all. Pugmarks are the most frequent sign. The author holds that their shape and size are largely individual and also show sex, so true tracings taken on comparable soil can identify and sex each tiger. Tracings are made on a “tiger-tracer”, with at least two left hind pugmarks, the soil type, wet or dry ground, and at least five stride measurements.
• Other evidence. Reliable local information, sightings, kills, scat, claw marks, calls, dens and shed hair are also recorded.
• Comparing the data. Supervisors compare the records of neighbouring units to remove double counts and decide whether one or more tigers share an area.

The paper sets out the staff structure (from forest guard up to five zonal co-ordinators), the census schedule, the equipment (tiger-tracer, 2 m tape, plaster of Paris, polythene bags, notebooks), the counting sheet and the state summary form. Days 1 to 5 were for searching and collecting evidence during normal duties; on days 6 and 7 each participant walked the longest possible route between dawn and 9.30 a.m. along the paths most likely to hold pugmarks.

In Part II, the author gives excerpts from his own log book of the census week in the Similipal Hills, Orissa, from May 15 to 20, 1972.

2. What they found

The author’s census week in Similipal

• He spent 6 days surveying and tracking, drove 428 km by jeep inside the forests and tracked 33 km on foot.
• A male tiger from scat, hair and a den. Fresh scat containing sambar hair led to old porcupine burrows that a labourer said a tiger used. Rub marks on a root across the entrance, soft white chest and belly hairs in the largest burrow and orange side hairs in a shallow one confirmed a tiger. The labourer judged it a male from the broad head and size.
• A male tiger from a kill. On a hard hill road, a shallow 45 cm depression lined with clawed-out tufts of soil and a spray of barking deer hair showed where the deer had been grabbed and lifted clean off the ground. The author reasons that a panther would have killed and dragged it, so this was a big tiger. A strong smell of tiger and a recent sighting by labourers supported this.
• A male and a female from lines of pugmarks. His companion Nihar spotted two fresh lines of pugmarks from the moving jeep, about 8 km apart. The male’s average stride was 71 cm. The tigress left 38 pugmarks, all with the hind foot exactly over the front; of 15 strides measured, 9 were exactly 53.5 cm.
• A tigress from a skid mark and her cave. A former forest guard spotted a distorted mark where a tigress had slipped on loose soil and spread her toes to stop the skid; the dewclaw showed it was her right front foot. Her rocky den up the hill held orange hair, and local workers had heard her calling.
• Two tigresses from pugmarks kept by forest guards, one from a convincing plaster cast and one from a clear pugmark preserved on a road edge.
• A mistake. Two “pugmarks” preserved by a new forest guard turned out to be a human footprint and a hyena’s hind track over a cattle hoof mark. The soil was fluffy and the tracks old; the experienced former guard made no mistake.
• Totals: 7 tigers confirmed (3 males and 4 females) and 5 reliably reported but not confirmed (2 males, 2 females and a cub).

Photographs and tracings show pugmarks seen through the tiger-tracer, a tiger walking fast with the hind paw ahead of the front paw, a panther kill identified from missing chest bones, a tree clawed by a tigress, and hair found in a steel trap pit as evidence of poaching.

3. What they concluded

• The only practical way to count tigers across the country is to train many people to recognise, age and interpret tiger signs, put them in the field at the same time, and compare their records.
• Pugmark tracings confirm individual tigers and clear up confusion when more than one tiger uses a unit. The census works best in winter, when tigers use open ground more and roads and paths hold more readable pugmarks. The summer 1972 census was mainly to train staff for a more efficient winter census.
• Only tigers confirmed beyond doubt are included. Reported tigers are searched for again and included only with further evidence or careful confirmation of local information.
• The counting units should become permanent “Tiger-Units”, each with its own history file, kept up to date from pocket notebooks carried by forest guards, as a basis for future censuses and management.
• The census also made forest guards look for and take an interest in the tigers in their care, which the author sees as one of its main benefits.

4. How tracking was or was not used

Tracking is the core of the method. Forest guards searched their units for pugmarks and other signs, made tracings and plaster casts, measured strides and noted soil and ground conditions. The author’s log describes tracks and signs identification (pugmarks, scat with prey hair, chest and side hair in dens, rub marks, kill signs, a skid mark with the dewclaw, claw marks on a tree), reading gait from superimposed pugmarks, telling a tiger kill from a panther kill, and correcting misidentified tracks of a human and a hyena. He tracked 33 km on foot and followed the tigress’s line of pugmarks along and across the road.

5. Tracker or observer certification

Reported but not validated. The author trained about 100 forest officers and honorary wildlife wardens in census methods, and Chief Co-ordinators trained the staff below them, but no test of their skill is reported. One former forest guard is described as experienced, and a new guard misidentified a human footprint and a hyena track as tiger pugmarks. The claim that tracings can identify and sex individual tigers with a high degree of accuracy is stated, not tested, in this paper; the author refers to his earlier papers in Cheetal for the technique.

6. Other technologies, skills or innovations

• The tiger-tracer, used to trace pugmarks, with standard details recorded on each tracing.
• Plaster of Paris casts of pugmarks.
• Standard counting sheets and a week’s log book, translated into local languages and issued in triplicate.
• Tiger-Unit history files and perforated pocket notebooks in duplicate for continuous recording by forest staff.

7. Implications for conservation (from the paper)

• Saving the tiger starts with confident, objective data on where tigers are and what condition their habitats are in.
• The main causes of decline named are the killing of prey, poaching for pelts, and loss of shelter for cubs through human use of tiger habitat.
• Tiger habitat crosses district and state borders, so counting has to be co-ordinated across states.
• Involving forest guards in the census builds their interest in the tigers they protect.