Bears and Douglas-fir: my perilous days in wildlife research in the Pacific North-west
The Black Bear of the North American Pacific North-west forests
I was reading Dangerous Dan McGrew, one of my favourite poems, for about the 50th time recently, and came across these lines: A bunch of the boys were whooping it up in the Malamute saloon; The kid that handles the music-box was hitting a jag-time tune; Back of the bar, in a solo game, sat Dangerous Dan McGrew, And watching his luck was his light-o'-love, the lady that's known as Lou. When out of the night, which was fifty below, and into the din and the glare, There stumbled a miner fresh from the creeks, dog-dirty, and loaded for bear. He looked like a man with a foot in the grave and scarcely the strength of a louse, Yet he tilted a poke of dust on the bar, and he called for drinks for the house. There was none could place the stranger's face, though we searched ourselves for a clue; But we drank his health, and the last to drink was Dangerous Dan McGrew. It was the line “loaded for bear” that struck me afresh. These days it has become just another cliché meaning “being prepared for danger”, but back in the days of Dangerous Dan, and in the wilds of the Alaskan goldfields, wise men carried the sort of rifles, loaded with the sort of cartridges, that could (hopefully) stop a hungry Grizzly. And all of this, started me thinking about bears. and my days in bear-friendly country.
Strangely (as Australia has no bears), I am one of the few Australian foresters who can claim to have carried out research into these animals, and their impacts on forests. The story came about this way.
After several years working as a young and itinerant forester in the South-West of Western Australia, I decided (in 1964) to return to university for post-graduate study. I had been greatly intrigued by my friend Jim Williamson’s stories about his experiences at Ann Arbor University in Michigan. I sent in an application to the University of Washington in Seattle, and they in turn appointed me as a “Research Assistant”. This covered my fees and living expenses while I studied for a Master’s degree in forestry.
Arriving in Seattle in the autumn of 1965 and meeting my professor (the famous Dr David R.M. Scott) I was surprised to discover the source of funding for my research position. The money came from the Weyerhaeuser Corporation, one of the largest timber companies in the US. The grant was provided to carry out research into damage to Douglas-fir (Pseudotsuga menziesii) trees caused by bears. I explained to Dr Scott that I knew nothing about bears and little about Douglas-fir, but he simply grinned, adding in his soft southern drawl “No worries, Raaj, talk to Barb Darbs”. He then went on to discuss my course work in the coming semester. Barb Darbs turned out to be Bob Dobbs, a Canadian who was just completing his PhD when I arrived in Seattle, and a good bloke. Barb gave me a lot of good advice. His research had been into the growth physiology of Douglas-fir, which I found curious as he had been funded by the same bear damage grant from Weyerhaeuser. But he also said “Don’t worry, Raaj” and added “I have the bear thing right under control”. However, I was worried enough to visit the faculty library for a quick read-up on bears. There I found that the Black Bear of the Pacific North-west (Ursis americanus) was the smallest of the three bear species found in north America (the others are the Polar Bear and the Grizzly Bear), but could still reach up to 2m in height, climb trees, out-run a human, has huge razor-sharp claws, is a man-eater and is usually bad-tempered. I made a mental note to stay out of their way.
The entry to Pack Forest - the University of Washington's private forest Out in Pack Forest (the University’s experimental and teaching forest, with beautiful stands of Douglas-fir) a few days later, Bob Dobbs explained that Black Bears have a predilection to attack young trees, scraping and tearing at the bark with their enormous claws, severely damaging the tree and reducing its value and growth.
He then demonstrated his research approach. He had manufactured an artificial set of bear paws using lengths of lumber through which he had driven a cluster of 6-inch nails to simulate the claws. Wielding the paws, he had incurred vicious damage on the trunks of several very nice 40-year-old Douglas-fir trees. Each of the trees had nasty, deep wounds, with cuts into the sapwood and strips of bark removed. While I watched, Bob freshened up the wounds with a few dextrous stokes of his bear paws. He also showed me how he had equipped each wounded tree with a dendrometer (a device for measuring the diameter growth of a tree), and how the measurements from these he was comparing with the growth of undamaged trees nearby. It would be my job to continue to take the measurements after he returned to Canada, and to furnish the Weyerhaeuser Corporation with reports on the results.
This I duly did, getting no response. In the end I concluded that Weyerhaeuser was not seriously interested in this research, but was happy to continue to fund post-graduate students in forestry from various parts of the world, for which I was grateful. Over the two-year period I studied “bear damage” in the Douglas-fir forest at Pack, I saw not a single bear, for which I was also grateful.
I recalled these long-ago adventures recently when I came across an article on bear damage to the beautiful and valuable Himalayan deodar tree (Cedrus deodara) in an early edition of my favourite journal The Indian Forester. The article was intriguingly titled ‘Barking of Deodar Trees by Black Bears’, and I quote from it:
Considerable damage is done to deodar trees by black bears … the bark is stripped off, leaving large exposed surfaces of wood, sometimes completely girdling a tree, and usually extending to a height of many feet above the ground ... … the claw marks of the bear appear as white, streaky, vertical lines, close together, very clearly visible against the darker background of the resinous cambium. I have never seen a bear at work in stripping off the bark, but am informed that its object is to get at the soft resinous cambium, which it presumably eats.
Deodar forest in the Indian Himalayas
Further reading disclosed that bears were not the only native animals causing angst to Indian foresters through their depredations on the trunks of nice trees. A forester from the Upper Chindwin region of Burma submitted the following letter to the 1890 edition of The Indian Forester, under the heading ‘Bark-eating on the Part of Elephants’:
For the first time in my experience in Burma I am working in a teak forest which is evidently, in certain seasons, the home of numerous wild elephants. It is a grand forest, but the most curious thing to my mind is the terrible damage that has been done to teak trees by these elephants. Without exaggeration, nearly every tree you find has been more or less injured by the beasts, the exception being only the trees which are so placed as to be practically inaccessible. The elephants would appear to dig their tusks under the bark and rip it across, then pulling the bark off in strips with their trunks. I have seen many marks of the tusks left on the tree 8 feet from the ground, and the height from which the strips have been torn off is often considerably more than this. When the tree is not quite killed, the bark in time grows over the bared place; but I noted one tree of about 4 feet girth that bad been completely killed and every vestige of bark within 7 or 8 feet from the ground removed ... … The Burmans say [the elephants] eat the bark, but I never heard of it before, nor have I ever seen one of my baggage elephants touch a teak tree. There is magnificent feeding for elephants in the lower ground the year round, so it cannot be that they eat the bark of teak for want of better food.
Presumably, as with bears, the elephants were tearing off the outer bark to get at the sugary sapwood layer beneath, a technique passed on from one generation to the next.
In the same edition of The Indian Forester, there is an interesting echo to Barb Darbs’ bear impersonations described earlier in this story. An article entitled “Bear Damage in Kashmir’ reports that bear damage is universal over 2000 square miles of forest in this region. The bears attack the trees in spring when they have just emerged from their winter hibernation and are too weak to hunt but are very hungry. They tear off the outer bark and then claw open the cambium to lick out the sugary sap. Over 25% of trees are damaged; some are completely girdled and die.
Claws on a Himalayan Bear
The article also described a problem in the same forests with illegal bark strippers. Working secretly, people known as “Mochis” (the traditional leather shoemaking caste of India), would strip the bark from deodar trees, and from this they extracted tannin, used in leather-making. Bark stripping had long been banned by the Indian Forest Department because it kills the tree. However, the illegal bark strippers sought to circumvent the law by attempting to disguise their work as bear damage. After removing the outer bark, they would use a three-clawed iron instrument to score the fresh inner bark in imitation of bear marks.
The local foresters were not fooled. As one of them reported:
It was easy to tell who are the culprits, namely bears or Mochis, as the former leave the outer bark on the ground whereas the latter remove it for tanning leather.
Happily, Australian foresters have never had to deal with bears or wild elephants. I expect I am one of the few to have conducted research into the damage to trees caused by bears.
In retrospect, I admit that the contribution of my research to science and forest protection would have to be classed as laughable. Eliminating bear damage would require the elimination of bears, something that cannot be considered likely – not in the USA anyway. On the other hand, the Himalayan Black Bear has become rare, due to loss of habitat, wildfires and poaching. Presumably this unpalatable situation has, at least, reduced the depredation on deodar (and other) trees.
Before leaving the subject of bears, I do need to recount the occasion of a confrontation between a Grizzly Bear and my wife Ellen. Luckily, this did not take place on a remote trail in the mountains of the Pacific North-west, but in the Seattle Natural History Museum. However, the picture gives you an idea of how enormous and fierce these animals can become.
I am not sure if Grizzlies also claw the bark off trees, but if I came across one doing so, I long ago resolved to leave him to it. Back then, and to this day, I never carry a firearm in the bush, let alone one “loaded for bear”, and don't intend to start now.