March 24, 1996
Sierra Club Board of Directors, Wild Planet Strategy Team, &
Off-Road Vehicle Subcommittee
730 Polk Street
San Francisco, California 94109
Re: "Harmless" Recreation Kills Wildlife!
Gentlepersons:
It has been customary for people to assume that when we are not directly
harming wildlife, we are not harming them. Besides being a convenient
rationalization, this assumption is understandable: we assume that others, even
members of other species, are like us. We don't feel very threatened by the
presence of other species; we are, after all, the top predator. We also live
surrounded by plenty; most of us can't imagine what it is like to go hungry for
even one day. Wildlife, however, does usually feel very threatened by our
presence, and many organisms exist on a very tight (food/energy) budget. Also,
they often have much greater visual and auditory acuity than we do, and hence
can be disturbed by sensations that we wouldn't even notice. Amphibians, for
example, are extremely sensitive to vibrations.
"Traditionally, observing, feeding, and photographing wildlife were
considered to be 'nonconsumptive' activities because removal of animals from
their natural habitats did not occur.... nonconsumptive wildlife recreation was
considered relatively benign in terms of its effects on wildlife; today,
however, there is a growing recognition that wildlife-viewing recreation can
have serious negative impacts on wildlife" (Knight & Gutzwiller, p.257).
Technology has made it much easier for people to reach wildlife habitat,
including areas where access used to be difficult, such as cliff faces, caves,
under water, and inhospitable climates. Roads, trails, ORVs, mountain bikes,
high-tech camping gear, freeze-dried foods, and even waterproof maps are some of
the tools that allow people to travel far into wilderness in great comfort. That
and increasing population have squeezed and frightened wildlife out of its
preferred habitat, both temporarily and permanently, depriving it of needed
foods, shelter, and choice of mates. Roads are particularly pernicious, because
they not only give humans easy access to wilderness, but they fragment habitat,
because many cover-adapted species are afraid to cross them.
Speed is a big factor. Being encased in a motor vehicle greatly reduces
the sensations that you experience. Thus in order to obtain the equivalent
physical experience that a hiker acquires in a short walk through the woods
(complete with sounds, sights, smells, tastes, and touch), you have to drive a
great distance! Similarly, a mountain biker travels too fast to fully appreciate
his/her surroundings, and thus soon gets bored with the trail and needs to
experience another (and another and another). This is one reason why mountain
bikers are never satisfied, no matter how many trails they have access to, and
why they are exerting such tremendous pressure on land managers around the world
to give them ever greater access. (I asked one of them if there were any limit
to this process. He told me that no one would ever want to bike Mt. Everest.
However, only a few days later I saw an advertizement for a mountain bike trip
to Mt. Everest!)
Here are some of the damaging effects that the mere presence of a human
can have on wildlife: When an animal is guarding a nest, it can be scared away
("flushed"😉 for some time, at least while a human is present. Besides using up
energy that may not be plentiful, eggs and young are left exposed to dangerous
temperatures (hot or cold) and predators. The movement of the parent, or
sometimes the odor of the human, can direct predators to the nest, causing the
death of some of the young. Sometimes the parent in its rush steps on an egg or
knocks it or its young out of the nest, leading to certain death for the
offspring. Some parents may even abandon the nest or kill and eat the young, if
they are frightened or startled enough. Young can get left behind when a parent
flushes suddenly, get lost, and die of starvation or be eaten by a predator.
The stress of disturbance can increase energy needs, elevate heart rate
(possibly leading to death), force the animal to temporarily or permanently
abandon a feeding area, force it to become nocturnal, force it to spend a great
amount of time watching for humans, interfere with reproduction, and in general
decrease its productivity. Migratory birds, for example, have a limited amount
of time to stock up on food before their trip. They often spend long periods
flying over ocean, and can die if they don't have adequate nutritional reserves.
Because the Earth is losing some 100 species a day, worldwide, it is
very important that we quickly become better informed, and stop mindlessly
continuing "business as usual" in our approaches to wildlife and recreation.
Here are some relevant excerpts from Knight and Gutzwiller: "the notion
that recreation has no environmental impacts is no longer tenable.
Recreationists often degrade the land, water, and wildlife resources that
support their activities by simplifying plant communities, increasing animal
mortality, displacing and disturbing wildlife, and distributing refuse" (p.3);
Boyle and Sampson ... reviewed 166 articles that contained original data on the
effects of nonconsumptive outdoor recreation on wildlife. In 81% of them, the
effects were considered negative" (p.51); "Nature viewing, by its very
definition, has great potential to negatively affect wildlife. ... Predators
learn to follow human scent trails to nest sites" (p.55); "activities
[involving] nonmotorized travel ... [have] caused the creation of more ...
trails in wildlands.... These activities are extensive in nature and have the
ability to disrupt wildlife in many ways, particularly by displacing animals
from an area" (p.56); "Recreational disturbance has traditionally been viewed as
most detrimental to wildlife during the breeding season. Recently, it has become
apparent that disturbance outside of the animal's breeding season may have
equally severe effects" (p.73); "Birds can lose eggs and young when predators
attack nests after parents are startled into flight" (p.133); "Human occupation
and activity are clearly and directly correlated with declines in breeding
populations of birds" (p.135).
"People have an impact on wildlife habitat and all that depends on it,
no matter what the activity" (p.157); "Perhaps the major way that people have
influenced wildlife populations is through encroachment into wildlife areas"
(p.160); "a single visit to nest sites by people can cause nest abandonment"
(p.161); "Some goslings got lost in the dense vegetation when parents headed for
the pool, or parents swam off leaving goslings behind that could not follow"
(p.162); "Pregnant animals suffered higher stress from wildlife viewers, causing
some to abort" (p.163); "Outdoor recreation has been recognized as an important
factor that can reduce biosphere sustainability.... Indeed, recreational
activities, including many that may seem innocuous, can alter vertebrate
behaviour, reproduction, distributions, and habitats" (p.169); "Human
disturbance caused eagles to flush sooner than the other species, and eagles
rarely returned to a carcass following disturbance" (p.170); "Juveniles that get
displaced from familiar surroundings (e.g., home ranges) by recreationists may
also be more susceptible to predation" (p.172).
"Displaced animals are forced out of familiar habitat and must then
survive and reproduce in areas where they are not familiar with the locations of
food, shelter, and other vital resources.... Hammitt and Cole ... ranked
displacement as being more detrimental to wildlife than harassment or
recreation-induced habitat changes.... Densities ... of 13 breeding bird species
were negatively associated with the intensity of recreation activity by park
visitors, primarily pedestrians and cyclists" (pp.173-4); "off-road vehicles can
collapse burrows of desert mammals and reptiles" (p.176); "Compaction increases
the mechanical resistance of the soil to root penetration and can reduce the
emergence of seedlings" (p.184); "Soil compaction reduces the size of pore
spaces, altering the soil fauna" (p.189); "several studies have shown the
importance of contiguous, undisturbed habitat for many native species" (p.190);
"Recreational activities clearly have substantial and generally adverse
influences on terrestrial vegetation and soil, and on aquatic systems" (p.193);
"researchers have documented an increase in heart rate in different species when
approached by visitors, which can subsequently initiate other physiological
effects of stress, including death" (p.206); "Indirect effects may also occur
from development of trail networks and picnic areas, which not only remove
habitat, but increase habitat edge ... [, opening] these areas for colonization
by exotic ... species" (p.210); "Geese could not compensate for a loss in
feeding time" (p.251); "The ESA defines harassment as 'an intentional or
negligent act or omission which creates the likelihood of injury to wildlife by
annoying it to such an extent as to significantly disrupt normal behaviour
patterns which include, but are not limited to, feeding or sheltering'" (p.304).
"It is expected that outdoor recreational activity will continue to
increase, while the amount of wild land where wildlife may seek refuge from
disturbance will decrease" (p.327); "Recreationists are, ironically, destroying
the very thing they love: the blooming buzzing confusion of nature.... The
recreation industry deserves to be listed on the same page with interests that
are cutting the last of the old-growth forests, washing fertile topsoils into
the sea, and pouring billions of tons of greenhouse gases into the atmosphere"
(p.340); "Tom Birch ... argues that wilderness managers, charged with
incarcerating wilderness, are more concerned with the advancement of their
careers through achieving quantifiable goals (number of park visitors, total
revenues) and developing park and forest amenities (roads, 'scenic' turnouts,
restrooms, paved trails, maps, campgrounds) than with perpetuating the land
community of which they are a part" (p.344).
Ideally, we should be working to reduce all human access to wildlife
habitat. But at the very least, we should eliminate mechanical access (with the
exception of small compromises for wheelchairs).
Sincerely,
Michael J. Vandeman,
Ph.D.
References:
Knight, Richard L. and Kevin J. Gutzwiller, eds. Wildlife and Recreationists.
Covelo, California: Island Press, c.1995.
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I am working on creating wildlife habitat that is off-limits to
humans ("pure habitat"😉. Want to help? (I spent the previous 8
years fighting auto dependence and road construction.)