Photo Credit: Brian Hay
If there is such a thing as reincarnation, a person would definitely not want to come back from the afterlife as a small tree in elk country. Bull elk vigorously rake trees in the late summer to clean the velvet off their antlers and the intensity of tree trashing ramps up during the rut when aggression behavior of bulls skyrockets. Interestingly though, winter appears to be another time when bulls actively rub trees. The significance of winter tree rubbing might represent an undiscovered aspect of elk social behavior that biologists might need to factor into elk habitat management.
In the southern Rocky Mountain region of British Columbia bull elk tend to segregate from cows and live out the winter in sanctuaries typically comprised of small pockets of mature forest cover. Some of these sanctuary-like hideouts contain evidence that the bulls living in them are actively rubbing smaller pole-sized trees throughout the winter months. The intriguing twist seems to be that bulls are re-rubbing the same trees over a span of many years.
Curiosity Drives Conservation
To investigate the winter tree rubbing behavior I analyzed the history of the elk’s rubbing activity by looking at the tree’s growth rings. A similar technique is used by fire ecologists who study the fire history of an area. Fire ecologists can look at cross sections of very old trees that have survived numerous forest fires and determine the year that each fire occurred as well as the number of years between fires by counting fire scars in the growth rings. When a bull rubs his antlers on a tree and the damage is not severe enough to kill the tree, the result is a scar similar to what the heat from a fire creates. The tree grows over the scarred area left by the bull’s antlers but the year the rub was created is encapsulated into the tree’s growth rings in exactly the same way fire scars are. Each year the tree is rubbed becomes a marker in the trees growth rings that can be dated.
The cross section of an elk rub trees showing the rub scars and dates
The bulls in my pseudo-scientific study area had been rubbing the same trees repeatedly over a period of 16 years. On average, each rubbed tree had been re-rubbed roughly once every 5 years. Some trees were even re-rubbed every winter. The observations seem to suggest that bull elk might return to the same winter hideouts where, at some point during the winter, they rub trees which have been rubbed before. The maximum reported age of a bull elk from a hunted population is roughly 10 to 12 years old, however, a small proportion of bulls are reported to live longer. Based on these age considerations, it is plausible that the same bulls could be returning to these winter hideouts and re-rubbing the same trees over their lifetimes. The longest period between two successive rubs on the same tree was 16 years which means those rubs were most likely done by bulls from different generations but not necessarily.
Bear researchers have reported that generations of bears will use the same “mark” trees. These mark trees play an important role in bear breeding behavior and dominance. To bears, their mark trees are a communication tool. Is it reasonable to suspect that elk, that have more complex social and communication behavior than bears, could also use “mark trees” to relay messages? Talking with professor emeritus and authority on North America wildlife, Dr. Valerius Geist, he described that he has observed elk (especially females) rubbing their necks on larger trees during the spring of the year as a way of transferring the long neck hairs containing their scent onto the sticky sap covered surface of the scarred tree trunk. Dr. Geist says that during the rut, bulls also rub their necks on sapling-sized trees in order to leave behind urine scented neck hair. Elk that rub trees to transfer scent-covered hair typically prefer to use larger diameter trees though. A bull’s reasons for leaving scent-covered hair on a rub tree are likely motivated by breeding season behavior so tree rubbing behavior during the winter raises some interesting questions. When 4, 5 or even 16 years passes between rubs, one would suspect that any scent left by the previous bull would have faded in which case, logic would suggest that re-rubbing trees could be based on some kind of visual cue left behind on old rub trees.
An elk rub tree on winter range in southeast British Columbia showing years of repeated rubbing – is this an “elk talking tree”?
More Questions than Answers
The curious questions that this winter tree rubbing behavior presents include:
- Are these bulls actively rubbing trees during the winter because of an uncontrollable habit carried over from the fall rut?
- Is the fact the bulls seem to be seeking out and re-rubbing the same trees simply a function of being confined to smaller habitats during the winter?
- Or, could the visual signs left on these winter rub trees be a way that bulls communicate some sort of social message between individuals in the herd or across generations?
- Do these winter rubbing trees hold significance for the survival of elk on a given section of winter range?
- Are the rubbing trees spatial markers telling elk important information about their winter range?
- Most importantly, could these winter sanctuaries where bulls go to rub trees be significant enough that we shouldn’t be disturbing the sites during forestry or habitat enhancement activities?
Share Your Observations
Attempting to learn about all aspects of Nature before one’s time in the outdoors comes to an end is one of the hunter conservationist’s greatest virtues. As much as modern science has increased our understanding of wildlife and their habitats, there are many phenomena in Nature that still remain a mystery. Because of a commitment to conservation, hunter conservationists have the responsibility to take observations like the “talking trees” of elk and discuss them with biologists to stimulate new research that might improve how wildlife habitat is managed.
North America’s Wild Sheep – Ancient and Unique
Mountain sheep first appeared in the fossil records around 2.5 million years ago in Eurasia. During the Pleistocene epoch mountain sheep spread across the Northern Hemisphere. Around 750,000 years ago the descendants of today’s modern mountain sheep species reached North America and eventually occupied habitats from Alaska to Mexico. There are three recognized species of mountain sheep in North America and Siberia. Mountain sheep are part of the goat-antelope family and their closest relatives are the true goats and sheep-goats from North Africa. The domestic sheep, a descendant of wild sheep, is thought to be one of the first wild animals domesticated by humans.
Sheep taxonomy is always changing but currently science recognizes two species of wild mountain sheep in North America – Bighorns (Ovis canadensis) and Thinhorns (O. dalli). Bighorn sheep have three subspecies – Rocky Mountain Bighorn, Sierra Nevada Bighorn and Desert Bighorn. Thinhorns have two subspecies – Dall’s and Stone’s sheep. In North America, the mountain sheep lives in close proximity to other ungulates. According to Valerius Geist in his book Mountain Sheep: A Study in Behavior and Evolution, mountain sheep are some of the most specialized grazers because they have unique guts and teeth that allow them to survive on hard, abrasive and dry plants. These adaptations allow mountain sheep to survive in habitats where many other herbivores cannot.
Threats to Wild Mountain Sheep
By 1900, wild sheep were almost driven to extinction and by 1950 they had been extirpated from most of their historic ranges. The Badlands Bighorn subspecies, also known as the Audubon Bighorn, was sadly driven to extinction. The efforts of hunter and non-hunter conservationists helped restore and recover mountain sheep across North America. Conservation of wild sheep has also led to tightly regulated science-based hunting restrictions that ensure the long-term sustainability of the species. Even with the recovery of mountain sheep from extinction they are still a species of concern in North America and some populations are listed as endangered. Hunter conservationists climb to heights and observe wild sheep in places no other humans venture and they are the eyes and ears of sheep conservation across the continent.
The wild sheep’s habitat was among the first habitats to become severely degraded from invasive weeds, over grazing by domestic animals and land development. Sheep have an incredibly strong affinity for their home ranges so generations of sheep stay loyal to their traditional home lands and migration routes. Even after their habitats have been destroyed sheep continue to try to survive on them rather than move elsewhere. Consequently sheep try to live in residential, agriculture and industrial areas including active mine sites. While some sheep populations co-exist with people and industry other populations are at risk of extirpation due to their lack of willingness to move.
Wild sheep are highly susceptible to domestic sheep infectious diseases. Even though the North American wild sheep and its domestic cousin are descendants from the Old World (Africa, Europe and Asia), wild sheep do not have resistance to the infectious diseases of Old World sheep including the bacterial diseases Mannheimia haemolytica and Mycoplasma ovipneumoniae (or Movi). These diseases are fatal and can kill up to 90% of an entire wild population. Infectious disease is considered the greatest conservation threat to wild sheep in North America. Disease limits where wild sheep can inhabit and it limits conservationist’s ability to recover or re-establish some populations.
Bacterial diseases are contracted by wild sheep when a wild sheep comes into contact with an infected domestic sheep. Rapid disease transmission between individual wild sheep is unavoidable because mountain sheep live in tight knit herds and occupy very small home ranges. Separation programs where domestic sheep are fenced to prevent them from coming into direct physical contact with wild sheep may not be as effective as once thought since science is showing that a single sneeze from an infected domestic sheep can transmit infectious mucus at distances up to 60 feet. Domestic sheep can literally sneeze through their fences onto vegetation that nearby wild sheep graze.
The Noble Beast
Mountain sheep have been given the title of one of the most prestigious big game animals in the world. Theodore Roosevelt referred to mountain sheep as “one of the noblest beasts“. From the time that proclamation was made mountain sheep have been put on a pedestal by some hunters. In one respect being on a pedestal has been beneficial for sheep conservation in many regions of the world. When the vulnerability of a species is combined with high social value a species tend to gets the investment and protection needed to recover and sustain populations. Often it is the dollars from hunting that fund wild sheep conservation. Special Premier and Governor Sheep tags in North America have been auctioned off for hundreds of thousands of dollars with the funds going back into wild sheep conservation.
It could be argued that a downfall of wild sheep having this prestigious game animal title is that sheep hunting is becoming an elitist hunt for those that can afford it. Guided mountain sheep hunts are among the most expensive in North America and lottery type tags are among the most heavily applied for. In some jurisdictions the odds of winning a lottery sheep tag have once-in-a-lifetime odds; however, resident hunters in regions like British Columbia still have access to over the counter Rocky Mountain Bighorn and Stone’s sheep tags every year. Like the high-priced auction hunts, fees paid for lottery applications and tags are used to fund wildlife management so it not always a downfall that the wild sheep hunting opportunities are in high demand.
Some hunters in elite sheep hunting circles will compete to be recognized for their various types of “slam” sheep collections. Other hunters aspire for recognition that their ram made it into the “record book”. Competitions like these and the recognition that some hunters desire from their peers have contributed to some of the darkest aspects of sheep hunting. Shooting mountain sheep from aircraft, poaching them out of season, purposely killing sheep in the wrong management unit or jurisdiction, shooting sheep in National Parks and even cases where guided hunters have their pick of rams stored in a freezer when they arrive in camp are all cases known to North America wildlife law enforcement.
Science-based Sustainable Hunting – The Only Way
Sheep biologists combine population monitoring, habitat management and research to closely manage sheep populations and hunting across the continent. Many North American science-based hunting restrictions on mountain sheep limit hunter harvest to the oldest age-classes of rams which, is either defined by the extent of the ram’s horn curl (i.e., full curl) or is determined by counting growth rings (annuli) on the ram’s horns. Harvesting the oldest rams is a biological strategy that allows populations to be sustained without hunting ever being a cause of a decline.
Judging horn curl or age under field conditions is challenging for a hunter but a necessary part of sustainable mountain sheep management. As with almost every other game animal, honest hunters sometimes make honest mistakes and animals that should not have been harvested accidentally get harvested. Honest hunters report their mistakes and relinquish the animal to the state or province and the meat is donated to food banks or game fundraisers. Game Wardens and Conservation Officers typically treat self-reporting differently than those caught trying to evade the law.
North America has a system of reporting and documenting mountain sheep harvested by hunters and for ones found dead by using an internationally agreed upon horn marking system known as “horn plugging”. Horn plugging was a conservation program initiated by the Foundation for North American Wild Sheep in the mid-1980’s and the identification plug embedded in the horn is now the universal verification showing where a ram was harvested and that it was legally harvested or found. In essence, the plugging system is a type of anti-poaching deterrent.
The Dark Side of Mountain Sheep Hunting
Despite horn plugging and science-based hunting restrictions, the egos involved in some hunting circles is sadly fueling another illegal activity that threatens the North America hunting heritage and the conservation of wild sheep. Stories of “horn cranking” have floated around for decades. Horn cranking was said to be the practice of steaming and twisting ram horns into a legal curl by tightening leather straps that were bound around the horns as they were softened by the steam. More recently the simple invention of the ratchet tie down strap used for securing cargo has become a tool of poachers. Stories now float around hunting circles that say poachers are shooting rams that do not have legal horn curls and with the use of a ratchet strap they are literally cranking the horn into a legal curl right on the mountain before the animal is even skinned and packed out. Other accounts suggest that the horns still have to be steamed if they need to be cranked a lot to manipulate them into a legal curl. I know biologists that have tested the method and it does work. The curl of a ram’s horns can be manipulated.
Make no mistake – horn cranking is not justified under any situation. Horn cranking is not being done by honest hunters who feel that if their ram horns are just a “little bit short” of legal curl that they shouldn’t have to be turned over to a Game Warden. People engaged in horn cranking are poachers. Poachers are criminals who are stealing public property in the form of wildlife theft. There are reports that these poachers are so sophisticated in horn cranking that they are purposely shooting illegal rams because they know they can crank the horns up to having a legal curl.
The Consequences of Silence
I’m sure this article will bring its share of criticism from some hunter types because they will claim (complain) the exposing of horn cranking is giving non-hunters/anti-hunters more evidence to attack hunting. This doesn’t change the fact horn cranking is taking place, that it is illegal and law enforcement agencies are trying to catch these poachers. Others might say that this article gives poachers ideas how to do it now. Silence is not an option though. Horn cranking has the potential to lower the age of rams being harvested from a population because it allows for younger rams with smaller horns that the biologists do not want killed to be shot and made “legal”. Ultimately, the removal of too many younger age class rams will lead to an unsustainable hunt or worse, population declines. Because harvested rams are inspected by biologists and Game Wardens, the ages of harvested rams from any given management unit is known. Once biologists see that the average age of harvested rams is dropping and that it is negatively affecting population stability the hunt will either be restricted or eliminated in the name of conservation as it rightly should. Once large scale arrests and convictions of poachers involved in illegal horn cranking begin to sweep across North America, the reputation of the hunting community as whole will be tarnished. This is a hit that the future of hunting can ill afford.
What Can Hunter Conservationists Do to Stop Horn Cranking?
Like all hunting in North America, poaching is the exception and poachers are fewer in numbers than law abiding hunters. Poaching is not hunting and poachers are not hunters. Conservation, fair chase, ethics and upholding science-based hunting laws must never be allowed to fail. It is the responsibility of every hunter to report every suspected poaching activity. The goal of this article is to inform as much of the enormous number of honest, ethical and responsible hunters across North America as possible about the illegal practice of mountain sheep horn cranking using ratchet straps. There is only one thing worse than a poacher and that is someone who knows about an illegal act against wildlife and chooses not to report it.
A hunter conservationist’s first step must be to report suspected cases of someone cranking sheep horns. Educate yourself about sheep conservation and tell others what to look out for with respect to how sheep poachers are operating. Obvious red flags are ratchet straps in someone’s hunting gear, steaming a set of horns or a homemade ram horn jig in someone’s garage. Talk to your state or provincial biologists and policy makers about this issue and help them find ways to tighten the laws around this illegal activity. Currently, as far I have been able to find out, there is no legally defensible method for a Conservation Officer or Game Warden to detect when hunter-killed ram horns have been “cranked”. Without a defensible form of evidence an officer can’t make any type of charge because it won’t be upheld in court.
Lastly, and most importantly I am calling on hunter conservationists, wildlife enforcement officers, law makers, wildlife forensics experts, academic researchers and hunting conservation organizations across North America to unite and fund the research that will lead to the discovery of a defensible method that can confirm when ram horns have been cranked. Rigorous peer-review research and modern technology are the only tools that will lead to simple and defensible field verification procedure that will give wildlife officers the best chance that charges will be upheld in a court of law. Ultimately the convictions, loss of hunting privileges, public exposure and a larger number of eyes and ears will make life too risky for poachers to continue. I urge the Wild Sheep Foundation and its’ state and provincial affiliates to take the lead role, as they always have with every other mountain sheep conservation issue, and unite the people needed to bring a stop to the criminal activity of sheep horn cranking.