Markings as Indicator of Snow Leopard in Field Survey, in Xinjiang

1. What they did

Snow leopards are rare, secretive, solitary and active at night, and they live at high altitude, so they are hard to study directly. Signs are one of the most important ways to learn about them. The Xinjiang Snow Leopard Group, funded by the International Snow Leopard Trust (ISLT) and the Xinjiang Conservation Fund (XCF), surveyed snow leopard signs in the Altay and Tianshan Mountains of Xinjiang, China.

• Preparation. The team wrote a field survey manual, and every member was trained beforehand in basic methods, including how to recognise snow leopard scrapes, footprints, scats, scent spray, hair and claw rakes.
• Transects (September to November 2004). They walked 67 transects at 9 sites, following the Snow Leopard Information Management System (SLIMS) designed by the ISLT. Transects were 250 to 1000 m long and 10 m wide, at least 1 to 3 km apart. For each, they recorded the Global Positioning System (GPS) position, length, number of signs, habitat, grazing and protection status. They measured and photographed footprints and scrapes to learn about individual differences, age and sex.
• Questionnaires. They talked with more than 200 local herders, hunters and reserve staff about snow leopards, their prey and conflicts with people.

2. What they found

Signs on transects

• The 67 transects covered 47,776 m (713 m on average). Snow leopard signs were found on 27 of them: 118 signs in total, or 2.47 signs per km.
• These were 41 footprint trails, 45 scrapes, 28 scats, 1 scent mark and 3 claw rakes.
• Sign density varied widely between sites, from none at Mori and Kozbay Vale to 7.37 per km in the Baitag Mountains and 4.41 per km at Yinyar.
• On one 311 m transect, three parallel trails (a female and two young) plus two other signs gave 16 signs per km.

Where snow leopards still live

Populations remain in the Tomur Peak area of the Tianshan and the Baitag Mountains. In the eastern Altay and at Mori in the eastern Tianshan they are now very scarce, although questionnaires suggest there were a fair number about 40 years ago. The main causes given are retaliatory killing by herders and a shortage of natural prey.

What each sign showed

• Footprints: left in snow, mud and sand. Adult prints were 9 to 10 cm wide and 10 to 11 cm long, with four toes around the pad. The authors compare a footprint to a “fingerprint” for telling age and sex.
• Scrapes: the most common sign, possibly from the habit of covering scats. Single, or up to 20 together. Where a snow leopard had been active, there was about a 50% chance of a scrape, and nearly half of all scrapes were at places that already had scrapes.
• Scats: can last a long time, especially where it is dry with little sediment and insect activity. Often near food remains, or at or within 1 m of scrapes. More than 40 were found, about 28 of them on transects.
• Scent spray: a territorial mark at busy sites, usually 70 to 85 cm high at the base of rock walls, sometimes with a distinctive smell. It fades quickly.
• Urine: easily confused with scent spray. At least 3 were found, sprayed in different ways and covering a larger area.
• Claw rakes: on rocks or thick tree trunks, in different places from scrapes, mostly within a few metres of scent-marking sites.
• Hair: found on marking rocks, showing where snow leopards had rubbed their face or body.
• Sleep sites: very hard to find on cliffs, but occasionally found near large prey carcasses, with fine shed hair.
• Bloodstains: smeared on rocks near fresh carcasses, usually where a snow leopard had wiped their mouth. Four were found (not all on transects), and there were also drops of blood along a route where food had been carried.
• Prey remains: at least 8 yak carcasses at Yinyar had been eaten by snow leopards. In the Baitag Mountains there were remains of Siberian ibex and argali, with other snow leopard signs nearby.
• Roars: as winter begins and snow leopards look for mates, sustained roaring was heard twice at night, between 19:00 and 01:00.

Habitat

Signs were found at 2000 to 3900 m. Signs per km differed clearly by terrain: highest on terraces or bluff edges (about 5 per km in Figure 2), then valley bottoms and cliff bases, and lowest on ridge lines. By vegetation, shrub had the most signs (about 2.9 per km in Figure 3), then grass and forest, with barren ground lowest. The authors suggest the cover in shrubland makes it the place snow leopards are seen most often.

Questionnaires

The authors report that the questionnaire results broadly agree with the field results, but give no figures.

3. What they concluded

• Combining sign counts and signs per km picked out the most important snow leopard areas among the 9 sites, and gave information on distribution, activity, home range, food and prey, and habitat selection.
• Based on field experience, the number of signs is related to relative population density and can be used as an index. Estimating actual density or numbers needs other surveys as well, such as counts of hoofed prey animals and radio tracking.
• Sign counts are only a relative measure and should be treated with caution: they depend on the number and size of transects, season, terrain, slope, aspect, altitude, climate, vegetation and how long signs last.
• Apart from possible confusion with lynx and wolf, identifying snow leopard signs in Xinjiang is not very difficult, because no other large cat of similar kind lives there. Footprint measurements can help tell individuals, age and sex apart, and DNA analysis of hair and scats would make identification more accurate.
• Heavy snow covers scats and scrapes in winter, which is one reason fewer signs were found in the Tomur Peak area. Grazing, tourism, mining, logging and poaching shorten how long signs last and make surveys harder and less accurate.
• Knowing the distribution and numbers of prey is very important. Prey information came from interviews and from recording all prey species and their signs (such as footprints and scats) found in the field.

4. How tracking was or was not used

The whole survey rests on tracks and signs identification. Trained team members walked set transects and recorded snow leopard footprint trails (in snow, mud and sand), scrapes, scats, scent spray, urine, claw rakes, hair, sleep sites, bloodstains and prey remains, and noted roars at night. They measured and photographed footprints and scrapes. Sign counts per km were then used as an index of relative abundance and habitat use. No trailing was reported.

5. Tracker or observer certification

Not reported. Team members were trained in basic sign recognition before the survey, using a field manual, but no certification or test of their skill is described. This matters because all the findings depend on correct identification, and the authors themselves note possible confusion with lynx and wolf signs, and between urine and scent spray.

6. Other technologies, skills or innovations

• The Snow Leopard Information Management System (SLIMS), a standard sign transect method designed by the International Snow Leopard Trust.
• GPS positions for each transect.
• Footprint measurement and photography (Plate I shows a measured footprint).
• Questionnaires with more than 200 local herders, hunters and reserve staff.

7. Implications for conservation (from the paper)

• Sign surveys give a first picture of habitat selection, range, distribution and relative density, which matters for estimating population size and for protecting and managing the species.
• Retaliatory killing by herders and the loss of natural prey are given as the main causes of the snow leopard’s decline in the eastern Altay and eastern Tianshan.
• Surveys of prey numbers and distribution are needed alongside snow leopard surveys.