From: Brian Horejsi
Subject: bears and bikes x Horejsi
Date: Tue, 5 Aug 2014 08:33:53 -0700

Mountain biking impacts on bears and other wildlife by Brian Horejsi


This is a short email that Brian Horejsi sent me on mountain biking and bears. It is a thoughtful review of how mountain biking can have substantial impacts on wildlife.

Of bears and mountain bikes!


The basic science of human – wildlife interaction solidly supports the general claim that mountain bikers and bikes are displacing bears (and almost all other species), can contribute to their habituation and are consequently adding negative load on human / wildlife conflict. I think it has been conclusively established that most kinds of human activity / presence displace bears, and if/when there are bears that are not displaced and/or become habituated, they die at a disproportionate rate, consequently their reproductive fitness is reduced (as is that of their mothers and fathers). Amongst the leading agents of displacement are industrialized forms of human activity that depend on machines / motors / mechanization to move people great distances, move them often and quickly, and with considerable "baggage" (garbage, guns, trailers, ATVs, dogs, and so on).  Mountain bikers fit the general category of industrial users, since they come by vehicle (mechanized means), move greater distances and more quickly than people on foot, (allowing quick approach and surprise encounters), have escalated their use of all public lands, and are a behavioral cult in which a significant proportion of participants exhibits high levels of aggression, partly against the environment, partly against traditional outdoor users,  and partly against members of society who identify their activities as destructive.  


Cumulative Impacts

Another not inconsequential impact of mountain bikes and bikers is they have forced themselves into landscapes that historically and even quite recently did not have traditional mechanized vehicle access. There are literally hundreds of formerly “mini” security areas (of a wide range in size) in local and regional parks (and this is in additional to what are thought of as traditional public lands - National parks, National or State/provincial Forests, and in the US, BLM lands) that harbored some forms of wildlife because they had limited and low access refuge areas. These are the "homes" of urban deer, coyotes, badgers, even bears and cougars, that are no longer providing day time (high human activity time) refuge and escape (from humans, pets and daytime heat).


I was just in Calgary a bit back and went for a walk in a provincial Park (Fish Creek) inside Calgary city borders that formerly contained some forested refuge lands. These areas were cool, relatively dark, and discouraging to most (almost all) walking and running Park users. I was dismayed to see the extensive mountain bike roads, along with formal support of biking. The dense aspen and spruce/pine stands that I estimate were 5 - 50 acres in size, and functioned as ecological and behavioral "spaces" that provided security and thermal refuge for wildlife, are gone. The bike roads are well used (there are 1.2 millions people in the city, and there ARE bikers) and now bring bike and biker threats to wild animals that formerly had a daytime hideout.  One such threat (there are several) is the common practice of bikers who “run” their pet dogs when they bike, dogs that are often allowed off leash (most often illegally), and are not only a threatening presence to wildlife via odor, sound and movement, but can be expected to (not uncommonly) leave the road and, at least short term, pursue wild animals. But it remains the bikes and bikers who are most intrusive. While there are high levels of use of the initially established paved trails the majority of users (walking, hiking, running, just wanting to be outside) stick to them and leave the formerly off trail areas alone. Because of bikers and their roads, this “standoff” no longer exists (to the detriment of wildlife).


And it gets worse! The demand / need for refuge from humans is greatest when human use is highest, usually on weekends. Previously un-biked niches in the landscape are of disproportionate ecological value during these peak periods. So, what happened?  These refuge habitats have been dissected by bike roads, which are destructive by themselves, but biker use also peaks on weekends, aggravating loss of habitat effectiveness at a time when demand / need for it is greatest, so the negative impact of biker use is not linear in relation to the increased number of bikes, but exponential given conflict with the elevated need for refuge by wildlife.



Will this result in or increase the level of wildlife habituation? Any activity that escalates contact (space, visual, sound) between humans and their infrastructure and an animal changes the ambient environment for an animal and produces some sort of learning in a wild animal. If the learning modifies behavior by eliminating or altering the strength or frequency of behaviors in response to a given stimulus (human yelling at it from the back yard, vehicle sound/movement, visual presence of human structures, dogs barking) and that initial behavior contributed to that animals fitness (survival and reproductive success), then that animal is subject to increased risk of injury and death and, consequently, life time reproductive success is jeopardized.


It may well be that the invasion of bikes/bikers “forces” contact with humans and leads to a more delicate and potentially explosive conflict. While I can't find any evidence in the scientific literature to support this particular situation, it seems reasonable to consider that an animal forced from its routine and from secure (to whatever degree) habitat, makes for an uneasy state of contact with humans and their infrastructure – a condition that could be more explosive due to the stress level related to the forcing. This contrasts with contact that might be initiated by the animal or other animals – for example, attraction to food, or a bear female with young that wants to avoid other bears and but can still use that habitat other years when she has no young or when other bears are absent. In the case of biker/biking displacement there is essentially permanent displacement and limited, if any, opportunity to reoccupy formerly (more) effective habitat. In other words, the predictability or stability, even strength, of the forced habituation could lead to unpredictable confrontation.


Could local residences and human centers of activity begin to experience use by wildlife that formerly stayed away? I don’t think there’s any doubt about it.   The consequences will be / are that fragmentation and use of refuge areas by bikers and bikes will reduce their capacity to harbor animals, displace them and their use/activity to other adjacent landscapes, many of which will be ecological traps, increase conflict with humans (and other animals), and incrementally reduce overall wildlife use of the larger area as well as reduce population size, distribution and movement. All these will unbalance wildlife dynamics and contribute to long term, incremental reduction of population viability.


The social / educational loss of tolerance for wildlife (the deer eating the roses, the black bear “near” the fence, the bear that “threatened” a biker) that some parts of human society can develop are also (generally) unproductive by-products of conflict and association: amongst these are distrust of, anger towards, and fear of “wild” animals, and not just local animals, but generalized attitudes to wildlife on a much larger scale of human perception, as well as resentment and irritation toward, and consequent decline in support of wildlife  and land conservation and the people who are supposed to be doing it.


This large scale negative outcome of mountain biking invasion of a landscape is just another cumulative effect of catering to extreme recreation and the shrill political intimidation of mountain bikers. With stunning ease the mountain biking lobby has overpowered citizens and local councils and regulators/managers and crushed, derailed and/or displaced traditional uses and wildlife and land conservation measures and initiatives in urban and municipal Parks and landscapes.


While mountain biking and bikers continue to build a legacy of environmental destruction and social conflict that has been ongoing in a large scale way on National-state-provincial Forests and in National Parks, their invasion of urban and municipal park areas is “new” and threatens to destroy further the already stretched and frayed tentacles that connect the natural world to the majority of Americans and Canadians that now live in Urban areas.



Dr. Brian L. Horejsi

Calgary, AB and Penticton, BC

07 August 2014