Conservation – Marking

wildlife biologist measures snow leopard tracks in the snow

 

What sign do snow leopards leave and why do they leave it?

Snow leopards leave evidence of their presence through pugmarks, scrapes, feces, scent-sprays, claw-rakes and the remains from kills. When a snow leopard scrapes, it leaves behind its own scent, presumably indicating who it is (a resident or transient individual), its sex and whether or not it is ready to breed. We have been able to detect the odor of snow leopard scent-sprays for as long as 40 days after being made by the cat, though the cat’s sense of smell is undoubtedly much better. Scrapes may persist for a year or more if made in gravel or protected by overhanging rocks. Many scrape sites are regularly visited and refreshed, leading to well-sculptured scrapes at what we call “relic sites.” As much as 40% of all scraping activity involves remarking of existing scrapes (Read the pdf publication, Ahlborn and Jackson, Marking in Free-Ranging Snow Leopards in West Nepal: a Preliminary Assessment). Such sign helps solitary snow leopards communicate with one another, enabling males to stay out of each other’s way and thus avoid a potentially dangerous confrontation. They may also help a female with cubs avoid infanticide by those males who did not sire her litter. These signs are, in effect, the snow leopard’s visiting card intended to inform all other individuals of its presence and, we also believe, afford it priority or “ownership rights” to a particular place.

Telemetry studies reveal that male and female home ranges overlap to varying degrees, and that males appear to be less territorial than jaguars or tigers. Importantly, use of a particular area is typically separated temporally, so that only one individual is present at a time (except during courtship of course). In Nepal, for example Rodney Jackson and Gary Ahlborn (read Snow Leopards Panthera Uncia in Nepal—Home Range and Movements) determined that 42-60% of home range locations for four cats occurred within 14-23% of their respective home areas: these commonly-used core areas intersected the most favorable local topography, habitat and prey base. Mountain ridges, cliff edges, and well-defined drainage lines served as common travel routes and sites for the deposition of sign, including scrapes, scats and scent marks (Ahlborn and Jackson, Marking in Free-Ranging Snow Leopards in West Nepal: a Preliminary Assessment). Core areas may be marked significantly more frequently than non-core sites, suggesting that such marking may help space individuals and thereby facilitate more efficient use of sparse resources. The more visible a scrape, the more likely it is to be remarked – in effect freshened up to cover the scent of another individual. Marking frequency varies seasonally, reaching peak intensities during the narrow mating season which falls between January and late March each year.

It is not easy to age sign consistently or reliably, as many factors influence longevity. Exposure to the elements is a key one. For example, rain quickly destroys sign, while snow covers it and essentially ensures that it will not be detected during winter surveys. Pugmarks are extremely short-lived compared to scrapes, which may persist for a year or more as already noted. Livestock often destroy sign, although they are usually absent from the higher elevations during winter and early spring. Table 1 indicates major factors influencing the scheduling of sign surveys for snow leopards.

Read about snow leopard monitoring methods.

FACTORS AFFECTING SIGN

SEASON 1 2 3 4 5 6 7 8
Winter

*

-

+

*

+

-

-

-

Spring

+

*

*

+

*

+

*

+

Summer

-

+

-

-

-

*

-

+

Fall

-

-

-

*

-

+

+

*

Key to Symbols:

+   — Optimal time for survey
*   — Acceptable time
-   — Poor time

Factors affecting
sign detectability:

1   — Intensity of marking activity
2   — Accumulation of sign
3   — Presence of livestock (trampling)
4   — Amount of disturbance from weather
5   — Suitability of tracking medium or substrate
6   — Snow cover (hides old sign, helps in
tracking fresh sign)
7   — Site access & travel conditions
8   — Availability of “relic” sign