Puma communication behaviours: understanding functional use and variation among sex and age classes

1. What they did

Pumas live spread out over large areas and rarely meet, so they mostly communicate indirectly through scent marks. Their most common mark is the scrape: a small depression raked into leaf litter or duff with the hind feet, usually with urine and sometimes with scat. The authors wanted to know which part of a scrape matters, the visible scrape or the urine, and whether males, females and young pumas use scrapes differently.

They worked in the Santa Cruz Mountains of California:

• Finding community scrapes. They searched landscape features and areas pumas used often, followed puma tracks, and later visited GPS location clusters from collared males that were revisited more than 7 days apart. They measured scrapes and the tracks beside them to confirm pumas had made them. A community scrape was an area used by more than one puma, with roughly three or more scrapes within 9 m², and not linked to a kill or bed site.
• Capturing and collaring pumas. From 2008 to 2012 they caught 36 pumas with trailing hounds, cage traps or leg-hold snares, and fitted them with ear tags and GPS collars. Pumas without collars were identified on video by the spot patterns inside the upper leg, scars, tail kinks and old injuries.
• Filming. Motion-triggered infrared video cameras recorded 60 seconds each time they were triggered, at 45 community scrapes in all.
• An experiment. At 26 community scrapes at least 200 m apart, one person set out pairs of treatments on either side of the pumas’ usual route: a bare control (ground patted three times with gloved hands), 0.5 ml of male puma urine bought from a captive facility, a hand-made scrape, or a hand-made scrape with urine. Pairs were rotated monthly. They recorded which treatment the puma sniffed first, how often each was sniffed, and for how long.
• Watching natural behaviour. Leaving out the experimental reactions, they scored every puma visit from February 2010 to December 2012 for scraping, sniffing (nose within 15 cm), body rubbing, the flehmen response (lifting the head and curling back the upper lip to use the vomeronasal organ) and caterwauling (a loud call with many changes in pitch). They compared mature males, mature females and immature pumas (under 2.5 years), using only the first 10 visits by each male to each scrape so that males did not swamp the data.

2. What they found

The experiment

• Urine alone was no more attractive than the bare control: it was not sniffed first more often, more often overall, or for longer.
• A hand-made scrape, with or without urine, was sniffed first more often, sniffed on more visits, and sniffed for longer than either the control or urine alone. For example, against the control, a scrape was sniffed on 91% of visits versus 43%.
• A scrape with urine was not found first or sniffed more often than a scrape without urine, but pumas sniffed it for longer (3.7 seconds versus 1.9 seconds on average).

Who visited

• The cameras recorded 762 visits by pumas of known class, at least 25 individuals and 37 632 seconds of activity.
• Mature males made 73.1% of visits, mature females 22.1% and immature pumas 3.4%; 1.4% were a male and female travelling together.
• Visits lasted about 58 seconds on average, with no difference between classes.

How they behaved

• Scraping: mature males scraped on 78.5% of visits, mature females on 13.6% and immature pumas on 12.8%.
• Sniffing: common in all classes (89.6% males, 85.7% females, 76.9% immature pumas); males sniffed more often than immature pumas.
• Body rubbing: 12.4% of male visits, 2.7% of female visits, never by immature pumas.
• Flehmen response: 30.6% of female visits, 6.5% of male visits and 7.7% of immature visits (11.8% of all visits).
• Caterwauling: 9.3% of female visits, 0.4% of male visits, never by immature pumas.
• Time spent: males spent much longer producing signals (scraping, rubbing, calling: 22.1 seconds per visit) than females (3.3 seconds) or immature pumas (2.7 seconds). Females spent longer reading signals (sniffing and flehmen: 30.4 seconds) than males (13.7 seconds) or immature pumas (17.5 seconds).
• Females scraped more often than they urinated on males’ scrapes (13.6% versus 2.2% of visits).
• No puma was ever filmed spraying urine or scraping with the front feet. Females with cubs were never filmed scraping or caterwauling.

3. What they concluded

• The visible scrape and the urine do different jobs, and both are needed: pumas use the scrape to find a message and the urine to carry and read it.
• Males and females follow different strategies, supporting an earlier idea by Logan and Sweanor. Males visit often and advertise to possible mates (and defend territory). Females visit less, likely to avoid dangerous meetings with males that could lead to infanticide, and use their visits mostly to assess possible mates, probably around oestrus.
• Communication behaviours appear to develop with age: immature pumas, and apparently females with cubs, rarely take part.
• Flehmen was less common than in studies of captive cats, perhaps because captive cats meet fresh scent marks more often.
• Scrapes compete for attention: the more stimuli at a site, the less each one was investigated. Some males might make many scrapes to outcompete rivals. Other animals, such as scavengers, might use puma scent marks too.
• Because the visible part of a scrape matters most, community scrapes are good places for camera trap census work, and visual lures (perhaps with sound) may work better for pumas than scent lures.

4. How tracking was or was not used

Tracking helped the researchers find and confirm their study sites. Early in the study they found community scrapes partly by following puma tracks across the landscape. At each site they measured the width and length of scrapes and of the tracks beside them to confirm that pumas, not another animal, had made them, using Elbroch’s (2003) field guide to North American mammal tracks and signs. Pumas were also caught with trailing hounds. The study itself is about one of the main puma signs, the scrape, and about the urine and occasional scat that come with it.

5. Tracker or observer certification

Not reported. The paper does not say who found the scrapes or confirmed them from tracks. It does say all the experimental treatments were set out by the same person, and it thanks C. Wylie and D. Tichenor for help capturing pumas with hounds.

6. Other technologies, skills or innovations

• Motion-triggered video cameras with infrared flash (Bushnell TrophyCam), set to record 60 seconds per trigger. Video, unlike still photos, made it possible to time each behaviour to the second.
• GPS and radio telemetry collars (Vectronics Aerospace), and a custom GPS cluster program, first built to find kill sites, adapted to find community scrapes from locations revisited more than 7 days apart.
• A field experiment with artificial scrapes made with scent-free latex gloves and commercially collected puma urine, in a crossover design.
• Identification of uncollared pumas on video from spot patterns inside the upper leg, scars, tail kinks and old injuries; age from gum line recession at capture.

7. Implications for conservation (from the paper)

• Camera traps placed at community scrapes, rather than at random spots, would likely record more pumas and improve census efforts for a species that is hard to count.
• Scent lures are not the best way to attract pumas, and possibly other felids; visual lures, perhaps with sound, would likely work better.