Identifying Cougar Marks on Arbutus Trees

There has been some discussion on the subject of whether or not cougars (Puma concolor) also known as Mountain Lion, mark or scratch Arbutus trees. This paper is an attempt to show they do and will classify marks for easier identification and to speculate on their purpose, if any of the same marks.

On my walks on Southern Vancouver Island I noticed a number of marks on Arbutus trees and at the time I couldn't identify what caused them. I realized no other animal besides a cougar could match these claw patterns and they appeared similar in shape to those shown in guide books. The professionals I contacted could not confirm these marks from the photos I sent them. I believe there are no papers written on the subject of cougars marking trees.  The premise is that Mountain Lions use their sharp claws on tree trunks, possibly as a scent-marking behaviour.1

 

The outline of the claw print matches the shape of the paw. This is from the front left foot.

S 1 A recent shallow claw mark, the edges of the injuries are still sharp as little apparent healing was begun. Such a shallow type of injury can change little over time as healing is not necessary in shallow injuries; the edges will round slightly and become smoother. Even though in the centre of the photo there are only three marks from one paw mark, this is a classic cougar claw mark identifiable by the single leading mark of the arc. This leading edge shows the arc of the claws of which no other animal on Vancouver Island, I believe, conforms to. 

S 2  These marks at the height of perhaps 9 feet are in curious combinations. In this example, single claw marks, double claw marks and triple marks indicate a climb to much higher up this tree. Unlike prints on the ground, claw marks on a tree can literally take on wide variations of combination which is why, I think, cougar marks have been so hard to identify. Note the old and feint marks in the lower centre of the photo. The arc that we look for (centre right) is not perfect as the single mark on the right shows uneven placement but it would be from a front, left paw.

D 1  Deep claw mark injuries, as mentioned, involve a protective callus growth which is a noticeable bulge and because of that, is often is harder to associate with the origin of a claw mark.  Most deep injuries that penetrate the vascular cambium layer on an Arbutus tree heal to a convexity. Here, the callus growth is just beginning to show around the edges. Note the rakes on the right side.

This is quite an unusual set of two cougar claw marks. It appears that the lowest scratch on it's own which contains the cut that pulls to the right is that of a dew claw. In this overall set of marks, the fourth scratch from the right on close inspection seems to be pulled as well, suggesting that that part of the paw was dragged slightly to the right. This is one more example of an odd combination of marks that needed close observation. Because these marks were fresh when seen, healing, if necessary, hasn't begun so it is difficult to determine if the marks are shallow or deep.

 A- Claw Print, B- Rakes and C- Claw Marks.

Claw Print 

Claw prints appear to be a statement. They can be a single set of four individual marks, but occasionally they show up as three. They are found singularly, not in pairs as in left and right paws, not crowded by other marks and other marks are not overlaid over them. They are found in prominent places where they will be noticed and are often found five to six feet off the ground. They may warn of or advertise their territory, hence the reason for their prominent placement. Most often the individual scratches within the claw print are deep enough to cut into the wood below the vascular cambium layer where it's sharp claw can peel shavings which may protrude from the cut. If a cougar deposits a scent while marking, then this exposed sponge-like vascular cambium layer could retain the scent, a signal for other animals. 

Rake R 2 Rakes can exemplify the dexterity of the cougar claw no matter what the change in arboreal topography. 

S 4 Old and quite stable, these concave marks indicate a collection more common than any other style of mark they are seemingly in odd combinations that contrast with the familiar four or three in a row marks. This mix of styles shows their differing ages and fading stages as those in the lower section of photo are in the process of doing as the tree yearly sheds it's bark and adds growth. Most shallow marks will heal to a concavity on an arbutus tree.

There are unique indicators of cougar marks on Arbutus trees. Their claws can cut deeply and they can cut a crisp incision (the tear-outs being an exception) in smooth bark. The arch print pattern when multiple claws are utilized can appear when marking Arbutus trees.


Cougars have been described as secretive and elusive and hence they are difficult to study in the wild.


The above photos of arboreal marks provide us with information on a cougar(s) presence, routes and places where they have left their scent calling card. They may show us places frequented the most or areas which they return to repeatedly.

 


Written by Murrough O'Brien. Read the full paper here. 

Reference

1 Mosowitz, David,  Wildlife of the Pacific Northwest: Tracking and Identifying Mammals, Birds,              Reptiles, Amphibians and Invertebrates.   Timber Press Field Guide.  2010.  Page 211.

Bibliography:

Bolgiano,  Chris,  Mountain Lion: An Unnatural History of Pumas and People.   1995
Elbroch,  Mark,  The Cougar Conundrum: Sharing the World with a Successful Predator.  2020
Lawrence,  R.D.  The Ghost Walker.  1983
Stolzenburg, William,  Where the Wild things Were: Life, death and Ecological Wreckage in a Land of 
            Vanishing Predators.  2008   
Wild, Paula,  The Cougar: Beautiful. Wild and Dangerous.  2013

I'm indebted to and would like to thank the following for their professional expertise and support:          

Garbutt, Roddie     - forest health research technician
Grover, Andrew T. - research geneticist/tree physiologist