Scrape-marking behavior of jaguars (Panthera onca) and pumas (Puma concolor)

1. What they did

Solitary cats communicate with each other mainly by leaving scent marks. In Central and South American forests, the mark researchers find most often from jaguars and pumas is the scrape: the cat rakes its paw through the soil, leaving a cleared patch with a pile of loose earth at one end. Little was known about how the two species differ in this behaviour. The authors set out to describe when and where scrapes appear, which cats make them, and whether scrapes can be told apart by species in the field.

The work took place along forest trails in the Cockscomb Basin Wildlife Sanctuary, Belize, which has one of the highest known jaguar densities in the Neotropics.

• Scrape surveys. Two researchers walked slowly side by side, scanning the full length and width of each trail for scrapes and other big-cat marks. Each trail was surveyed once a week, for 5 to 26 weeks, between 2003 and 2005. In 2007 a 9-km trail was surveyed daily on 35 occasions over 8 weeks. Each new scrape was marked with twigs and ribbons so it would not be counted twice.
• Recording scrapes. For each scrape they noted whether it was single (one raking) or double (two parallel rakings with a ridge of soil between them), its location, its length and width, and whether it held a scat. Their working idea was that double scrapes are made with the hind feet and single scrapes with one front foot.
• Scat DNA. Scats found in scrapes were collected, and DNA was used to identify them to species. Scats were also collected opportunistically between 2003 and 2006.
• Camera traps. Pairs of cameras were set at intervals of less than 1 km along the survey trails. Jaguars were identified individually by their rosettes, and pumas by scars, wounds, botfly swellings and leftover juvenile markings. Sex was told from whether testes were visible.
• Linking the two. Scrapes within 1 km either side of each camera were compared with the jaguars and pumas photographed there, over days, weeks and whole surveys.

2. What they found

How many scrapes

• Scrapes were the big-cat sign found most often. Rates ranged from none to about 9.4 scrapes per kilometre per week, depending on the trail.
• Numbers swung widely from week to week, but there was no clear difference between dry and wet seasons.

Which cats scraped

• In the 2007 daily survey, 12 of 23 puma captures came on days with scrapes at the same camera locations, compared with only 7 of 37 jaguar captures. Many scrapes (34 of 53) appeared on days when no cat was photographed.
• Week by week, scrape numbers were best explained by how often male pumas passed the cameras.
• Over whole surveys, scrape numbers rose with both species. They tracked the number of individual male jaguars most closely, and male puma captures added further explanation.
• In weeks with only pumas on camera, scrapes rose with male puma captures. In weeks with only jaguars, there was no link (though there were fewer such weeks).
• Scraping did not rise with the presence of females of either species, and high scraping was not tied to any particular individual or pair of individuals.

Where scrapes were made

• Scrapes were strongly clustered. Most scrapes made in the same week were within 0 to 10 m of each other, and the same clustering held across weeks and whole surveys.
• Clusters were spread along the whole length of the trails. On a 10-km trail surveyed for 8 months, the longest gap between clusters was only 386 m.

Size and shape

• Almost twice as many single scrapes (824) as double scrapes (495) were found. Double scrapes were slightly shorter and wider, but sizes formed a single spread, with no clear jaguar and puma groups.
• From scrapes holding scats identified by DNA: pumas made double scrapes more often (17 of 36 puma scats were in double scrapes, against 4 of 28 jaguar scats).
• Jaguar single scrapes were bigger: on average about 36.8 cm long and 23.0 cm wide, compared with about 23.7 cm long and 20.1 cm wide for pumas.
• A video trap filmed a puma making a single scrape with one front foot, and a camera photographed a resident male jaguar making a double scrape with its hind feet.

Scats and urine

• Most scats found on trails were in scrapes: 265 of 350. Scats were placed on the pile of earth or on the raked ground, never covered, and were found only in new scrapes.
• Pumas left more scats in scrapes than jaguars did. At least 26% of puma scats were in scrapes, compared with at least 10% of jaguar scats.
• Puma scrapes with scats were 500 m or more from jaguar scrapes with scats made in the same week, but sometimes within 100 m (2 to 70 m) of other puma scrapes with scats.
• Fresh scats in scrapes could often be smelled from up to 10 m away. Cat urine was smelled near trails now and then, but never in a scrape. One photograph showed a male jaguar spraying low shrubby vegetation at the trail edge.
• No scrapes were ever found when walking off-trail or cutting random transects through the forest.

3. What they concluded

• Both species scrape, but pumas, and especially male pumas, scrape more often than jaguars. This fits earlier reports from elsewhere in the Neotropics and from North America.
• In the field, scrapes cannot be assigned to species with certainty from their size or shape alone; scat DNA is needed. Puma scrapes tend to be smaller and more often double.
• The clustering shows that cats respond to existing scrapes by scraping nearby, whether renewing their own or marking near those of others.
• Scraping does not seem to signal dominance or mark territory boundaries here: it was not tied to resident or particular individuals, and clusters were spread along the trails rather than in boundary zones. This fits the large overlap in the ranges of male jaguars and of male pumas in the sanctuary.
• Scrapes seem to play little part in communication between the two species. Countermarking within a species appears more common in pumas than in jaguars.
• The authors suggest that pumas, smaller than jaguars and never heard calling in the area, may rely on quiet signals such as scrapes rather than loud calls. Jaguar calls were common. Scraping may also signal a puma’s temporary presence in a low-density population, while jaguars may scrape more when other jaguars are around.
• Scrapes are the most frequently found signals, but that does not make them the main way these cats communicate; calling, spraying and rubbing are harder for people to detect. The role of urine needs further study, for example with black-light searches at night.

4. How tracking was or was not used

The study is built on tracks and signs identification. Two researchers searched trails for scrapes and other big-cat marks, recognised scrapes by raked ground with loose earth piled at one end (claw marks were never visible), told single from double scrapes, measured them and collected scats from them. They also noted the smell of fresh scats and of cat urine. Species was then confirmed with scat DNA, and the cats present were identified with camera traps. No trailing was reported.

5. Tracker or observer certification

Not reported. The paper says only that two researchers did the surveys and that all surveyors were familiar with the odour of large cat urine. The acknowledgments thank E. Pop “for field assistance and invaluable field expertise”. Park wardens collected some scats.

6. Other technologies, skills or innovations

• Paired passive camera traps (Cam Trak South), running 24 hours a day with a 3-minute delay between photographs.
• Identifying individual pumas from photographs by scars, wounds, botfly swellings and juvenile markings, an approach harder than for spotted jaguars.
• A video trap that filmed a puma scraping.
• Scat DNA (QIAamp DNA Stool Mini Kit) to identify species.
• Universal Transverse Mercator coordinates for each scrape.

7. Implications for conservation (from the paper)

• The authors suggest that marking behaviour may depend on population density, with scrapes advertising presence where cats are few and warning others where they are many. More data from areas with different densities of both species are needed to test this.