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Natural
History
A
Compendium of Environmental and Resource Information
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Columbia Basin Wildlife
Wildlife Subjects
Large Carnivores
Introduction
Carnivores eat meat; this is what
the word's Latin roots mean. "Carnivores" in taxonomic
parlance refers to members of the mammalian order, Carnivora.
All of the Carnivora eat some meat, but many are omnivores
(i.e., they eat a variety of foods, not exclusively meat) and some,
such as black and grizzly bears, eat mostly plants. Also, other
mammals besides those in the order Carnivora, such as bats,
shrews and toothed whales, are largely or exclusively meat eaters.
Carnivorous mammals are usually
distinguished by their ability to eat meat; the shape of their teeth
allows them to tear flesh. In virtually any setting, therefore,
large carnivores dominate the food chain, hunting or foraging for
their prey. Carnivores are not just takers though. In a healthy
ecosystem, these animals have integral roles, interacting symbiotically
with the plants and animals by spreading seeds, mixing soil and
decaying wood, breaking down prey through digestion, keeping prey
populations in balance, and by ultimately decomposing themselves.
People are drawn to large carnivores;
their power and splendor both intrigues and awes us. They are a
"charismatic" group, icons of conservation, which people
everywhere pester politicians to protect. These predators resonate
with us powerfully because, as long as humans and carnivores have
cohabited, we have been both their hunters and their prey. This
relationship has captured humans' imaginations, making carnivores
key in the cultural identity of British Columbia.
We fear them, and we revere them.
In British Columbia, nearly every year, someone is attacked by a
cougar, black bear or grizzly bear. They, in addition to wolves,
also may attack our livestock and directly threaten our livelihood.
Many people hunt them, too, following traditions with deep roots
in many of our cultures. Moreover, for some of us, the relationship
with bears is even more complex. In some First Nations cultures,
bears have a human spirit. If you saw one skinned, you would know
why: it looks almost exactly like a naked, muscular human, except
for the teeth and claws. In many Asian cultures, certain bear organs,
gall bladders for example, provide important pharmaceutical products.
Conflicts abound among humans on how large carnivores should be
managed. These passions can not be entirely dissipated by information
and logic, but one feeling is shared by all of us: British Columbia
would be a much poorer place without large carnivores.
Grizzly Bear
Grizzly and brown bears, Ursus
arctos, are one of nine species of the bear family; U. a.
horribilis is the subspecies found in British Columbia. "Brown
bear" means the grizzly bears on Kodiak Island, Alaska, other
nearby islands and adjacent parts of the North American mainland.
These are not to be confused with brown-coloured black bears (see
below). "Brown bear" also applies to the European and
Asian subspecies, and is the general term applied to grizzly bears
in North America. Although brown bears used to roam Asia, Africa,
Europe and North America, and they are now found only in Europe,
northern and eastern Asia (a population persists on Hokkaido in
Japan) and western North America. People have changed grizzly habitat,
alienated and eradicated bears from certain areas. The Columbia
Basin is home to some of BC's estimated 10,000 grizzly bears, providing
excellent bear habitat in the lush valleys and mountains.
 Grizzly
bears are synonymous with wilderness and integral to BC's cultural
heritage. They draw a myriad of feelings from people wherever they,
or their conservation issues, go. Perhaps some of the interest is
because of their enigmatic character. The bears are top predators,
capable of killing the largest prey in the Columbia Basin (moose),
yet they have a shy and solitary nature and eat a nearly totally
vegetarian diet for much of the year. The grizzly's potential threat
to human life and property has engendered an anti-grizzly attitude
in some areas of the province, making their management particularly
difficult.
Grizzlies are best distinguished
by the big hump of muscle over their front shoulders which enables
them to dig powerfully. Coat colour can include shades of blond,
brown or black, with long, outer guard hairs tipped a lighter colour
to give the bears the "grizzled" appearance responsible
for their name. An average adult grizzly bear weighs between 270
and 360 kg and will reach a length of 1.8 m. In spite of their big
and bulky shape, they can get going as fast as 55 km/hr on most
terrain. During their 25 years life span, a female will bear two
or so cubs every two to three years. The cubs stay with their mother
for two or three years, learning to hunt and forage in preparation
for their long winter hibernation period. More information on bear
hibernation and reproduction is in the Black Bear section, below.
Details on habitat use:
Grizzly bears choose their habitat
according to the availability of food, denning and mating sites,
and the presence of other  bears.
Each bear occupies a home range. Home ranges vary from 50 to hundreds
of square kilometres. Range sizes near Revelstoke were 188 square
kilometres for males and 44 for females (Simpson et al., 1985).
The Central Selkirk Mountains, a 9866 square kilometre, geographically
isolated area between Kootenay, Columbia and Duncan Rivers, hosts
an estimated 262 grizzly bears, an average of 26.6 bears per 1000
square kilometres (Mowat and Strobeck, 1998). Grizzlies are not
truly territorial and their home ranges may overlap. Except when
mating or rearing cubs, they prefer not to come in contact with
one another and use tree and trail marking as a form of communicating
their presence.
In the Columbia Basin, the grizzly
bear year can be divided into pre-berry, berry, post-berry and denning
seasons, since berries are the most important food for weight gain
and over-winter survival (Simpson and McLellan, 1990). In pre-berry
season, bears emerge hungry from their dens and, after a short period
of attendance near the den site (Harding, 1976), begin to search
for food, mainly hedysarum roots, carrion and winter-weakened mammals
they can kill easily (Lofroth, 1994). As green-up occurs first in
the valleys and then up south-facing avalanche paths, bears graze
on grasses, sedges, cow-parsnip, horsetail and rushes (Hamer, 1974).
They also prey on ungulates on their calving grounds during the
pre-berry season (Lofroth, 1994).
In early summer, berries ripen at
lower elevations, and ripening proceeds up the mountainsides as
the season progresses. Bears follow this altitudinal sequence of
ripening of berries, especially their favourites, huckleberries,
buffalo berries and blueberries, but also trailing blackberry, raspberries,
currants and service berries. South-facing burns and logged areas
are important for berry production. This usually keeps them in the
high country, but in years when the berry crop fails, grizzlies
travel widely (Simpson and McLellan, 1990).
After the blueberry/huckleberry
season, grizzly bears again begin to travel more widely, seeking
other berries (elder berry, mountain ash, bear-berry) and hedysarum
roots. Grubs, insects and small mammals such as ground squirrels
supplement the bear's diet throughout the active season. Between
feeding bouts, bears bed down where they are comfortable; they utilize
snow pockets, deep holes dug in cool sand, shady shrub cover and
trees to protect themselves from the elements.
In October-November grizzlies den,
usually on southern aspects at or above the tree line (Vroom et
al., 1980). Bears dig dens in avalanche paths, under tree roots,
or in other subalpine meadow habitats, although natural rock or
tree-hollow dens are occasionally used. Using a steep slope eases
digging, creates a heat trap and keeps snow out of the den while
letting it pile deeply at the entrance. The best soil for denning
is relatively dry and unconsolidated, with enough consistency to
prevent collapse. A cover of shrubs or herbs catches the snow and
provides roots which further bind the soil against collapse (Harding,
1976; Vroom et al., 1980). Grizzly dens are characterized by a porch
(created from excavation debris), an entrance tunnel, and a den
chamber with a bed made comfortable and warm by a lining of sticks,
moss and leaves (Lofroth, 1994).
Simpson and McLellan (1990) give
the following topographical and biogeoclimatic characteristics of
seasonally important grizzly bear ranges in the Columbia Mountains:
|
Season |
Elevation
(m) |
Aspect |
Zone |
| Winter
(Nov-Mar) |
>1700 |
S
SW |
ESSF |
| Early
Spring (Apr) |
<900 |
S
SW |
ICH |
| Spring
(May-Jul) |
all |
all |
ICH,
ESSF |
| Summer
(Aug-Oct) |
1200-1800 |
S
SW |
ESSF |
Grizzly Bear Conservation Issues
The Ministry of Environment, Land
and Parks manages grizzly bears through habitat management, the
maintenance of populations sufficient to support both hunting and
other recreational uses, and the control and regulation of human-grizzly
conflict.
Habitat Management
Grizzly bears in the Columbia Basin
have lost considerable habitat through damming (see Structure of
Aquatic Ecosystems) of productive valleys that were important at
critical times of the year (early spring foraging), and also through
the erosion of habitat by human settlement, agricultural development
and forestry. In addition, hydroelectric dams have annihilated a
major food source, as salmon no longer migrate up the Columbia River
to their original spawning grounds. Grizzly bears rely on a huge
fat and protein rich diet in the fall to build energy reserves to
sustain them through the winter. Judging by the importance of migrating
salmon in the diet of coastal grizzly bears, the loss of the Columbia
River salmon migration was surely a critical event in the life history
of interior grizzly bears and must have had an adverse effect on
their populations. The more recent reduction of kokanee salmon resulting
from the ecosystem collapse in the Kootenay and Arrow Lakes has
further compounded the protein loss.
Habitat management is now focused
on identifying and protecting critical grizzly habitat. Resource
developers must have their development plans appraised by habitat
managers who regulate the present and future impacts that human
activities have on grizzly habitat. Grizzly bear research in the
Rocky Mountains and in the Northern and Central Selkirk Mountains
will help habitat managers understand grizzlies' needs and reduce
industry's impacts on them. The forest industry, for example, has
reached a critical phase in the Columbia Basin, with less mature
than immature timber left to harvest, and much of the remaining
harvestable tracts in grizzly bear habitat. Together, developers
and managers must discover ways to provide for healthy grizzly bear
populations throughout their existing range by minimizing the intrusion
of logging access roads and habitat fragmentation.
Maintenance
of Grizzly Populations
Although hunting is well controlled,
now allowed solely by Limited Entry Hunting permits throughout the
Basin, illegal hunting for sport and for gall bladders for the Asian
traditional pharmaceutical trade presents a continuing challenge
to grizzly bear populations. Because neither the grizzly population
nor the amount of illegal hunting are precisely known, the provincial
government aims to be conservative in its management of grizzly
bears. Harvest levels are set so that legal hunting takes no more
than four percent of the estimated grizzly population annually.
Grizzly/Human
Interactions
Regulating grizzly bear-human interactions,
often fatal to humans and nearly always fatal to the bears, is a
continuing challenge. Humans have moved into the grizzly bears'
home ranges: building houses, flying helicopters, driving trucks,
dirt bikes and four wheelers, logging, mining, hunting, touring,
camping and mountain climbing. We are noisy, we smell funny (to
a bear), we mess up their marks and trails, sometimes we scare them
and often we impede their lifestyle. Grizzly bears have perfected
the patterns of their existence over millions of years of evolution,
and bears respond to our appearance in their habitat by instinct.
Their first instinct is to avoid human contact whenever possible.
If surprised or threatened however, bears may become very aggressive,
protecting their cubs, food or space.
Education is the key to minimizing
bear-human conflicts. Tips for safety in the wilderness are on the
MOELP website. School children in the region are visited by Conservation
Officers, Park Rangers and other wildlife experts who discuss appropriate
behaviour of both animals and humans in the wilderness. The Columbia
Basin Fish and Wildlife Compensation Program is sponsoring a Bear-Human
Conflict Education Program in the Revelstoke area, where bear mortality
and relocation rates have been some of the highest in the province.
This project is in partnership with the Friends of Mount Revelstoke
and Glacier National Parks, B.C. Environment, the B.C. Conservation
Foundation and the Real Estate Foundation of B.C. Other communities
in the Columbia Basin are now also starting bear education programs.
More
Information on Grizzly Bears
http://weber.u.washington.edu/~hammill/iba/iba.html
Information on bear ecology, conservation and genetics including
a summary of a recent workshop on applications of genetics
to bear conservation and biology: the "Gatlinburg DNA
Workshop." http://wlapwww.gov.bc.ca/wld/grzz/index.htm
The B.C. Ministry of Environment, Lands and Parks presents grizzly
bear information and programs, including the Grizzly Bear Conservation
Strategy.
http://www.nature-net.com/bears/
This site provides comprehensive data on all species of bears
of the world including grizzlies (brown bears) and black bears.
http://www.env.gov.bc.ca/kor/wld/final.html
This site holds reports on FRBC-funded Kootenay region wildlife
projects. Reports on the Central Selkirk Grizzly Bear Population
project and the Elk Valley Bear Inventory project, for example,
can be downloaded from this site.
Black
Bear
Unlike grizzly bears, black bears
are more or less ubiquitous in the forested areas throughout the
Columbia Basin. They do not require such large and specific tracts
of wilderness as their grizzled cousins; female's home range sizes
are between six and 26 square kilometres and male's are between
26 and 124 (Middleton, 1999). Black bears come in a variety of colours,
including black, brown, cinnamon, blue-white, beige or cream. The
size of average adult males ranges from 57 to 272 kg in weight,
and their length is usually between 140-180 centimetres. Black bears
have shorter claws than grizzly bears, and their feet are better
adapted to tree climbing.
Hibernation
The hibernation period for black
bears generally lasts four to seven months and dominates their lifestyle.
Energy-saving changes occur during hibernation: heart rate drops
from 40-70 beats per minute to 8-12 beats per minute; body temperature
goes down three to seven degrees; metabolic rate is cut in half,
and bears do not pass any urea or feces. Even in their torpor-like
sleep though, bears use up energy, so much energy that their body
weight after hibernation is 15-40% lower. In the spring, bears emerge
lethargic and hungry from their dens and almost immediately begin
to replenish their lost body weight. Later in the fall, they will
gain up to 14 kilograms per week in preparation for their big sleep.
Diet
Black bears are very efficient,
finding the most food with the least effort through scavenging,
foraging or hunting. They don't mind haunting garbage dumps or other
human food sources, learning quickly how to open garbage cans, access
pet food or pilfer an orchard, compost or barbeque site for food.
Black bears, like grizzly bears, are classified as carnivores, although
about 75% of their diet is vegetarian and 25% is live or decayed
animal matter.
Without the temptations of human
settlements, black bears can often be seen seeking the first tender
green shoots of spring on avalanche paths (never the same one as
a grizzly bear, at the same time!), roadsides and swamps. Berries
are important in their diet, and they tend to follow the sequence
and elevation of the ripening of different species of berries: first
strawberries, then raspberries, followed by blueberries and huckleberries
and finishing with mountain ash berries. Blueberries and huckleberries
are especially important, and the ripening of huckleberries at successively
higher elevations draws the bears deeper into the wilderness, away
from human settlements. When the high elevation berry crop is poor,
however, human-bear interactions seem more frequent.
Reproduction
Like grizzlies, black bears mate
in the spring or summer, but implantation of the fertilized egg
is delayed until the beginning of the denning period. If the bear
has not built up adequate fat stores to nourish both herself and
the fetus through the long months of winter hibernation then the
egg is reabsorbed by the bear's body instead of being implanted.
If the bear is in good health, the egg is implanted, the fetus grows
for 8 weeks and from one to four 240-330 gram baby bears are born
in the den. The cubs grow considerably as they suckle their sleeping
mother's rich milk (20% fat content compared to 4% in human milk)
in the den for five weeks. Spring arrives, bringing hibernation
to an end. The mother, having slept through the gestation, birth
and infancy of her cubs, awakens from her sleep to take her cubs
out into their new world. The cubs stay with their mother during
the summer and winter, learning to forage for food and protect themselves
from danger. They are driven out to make it on their own the following
spring.
Black
Bear Conservation Issues
Keeping black bears and people apart
is a chronic problem for wildlife managers, resulting in over 1600
bears (some grizzly, but mostly black) being killed in 1998 to protect
people and livestock. The Columbia Basin Fish and Wildlife Compensation
Program, with Friends of Mount Revelstoke and Glacier National Parks,
the Real Estate Foundation of B.C., B.C. Environment and the B.C.
Conservation Foundation, are sponsoring a bear-human conflict education
program in the Revelstoke area. Teaching people how to live in bear
country has turned the bear mortality rate in Revelstoke from one
of the worst in BC to one of the best.
Poaching of black bears for their
gall bladders for the Asian pharmaceutical trade increased during
the 1980's and 1990's. Conservation officers attempt to stop illegal
hunting in the field, and federal customs authorities regulate bear
products being traded internationally. Bear products are listed
under CITES, the Convention on International Trade in Endangered
Species and require a permit for transport across international
borders.
More
information on Black Bears
http://wlapwww.gov.bc.ca/wld/
BC Environment, Lands and Parks "Safety Guide to Bears
in the Wild"
Also, see websites listed above
under Grizzly Bears.
Cougar
Cougars (also known as puma, mountain
lion, deer tiger, Indian devil, Mexican lion) are elusive, stealthy
animals found throughout the Columbia Basin.
Habitat
and Diet
Each male cougar lives alone on
a home range of about 25 square miles, which he clearly marks with
urine-sprinkled scratch piles. Females similarly mark their home
ranges, which are between five and 20 square miles. Cougars defend
their territory and may kill offending cougars, even cubs, if the
population density becomes too high.
Preferred cougar habitat, characterized
as rough, rocky and semi-open ground, is found throughout the Columbia
Basin, but their distribution is governed by the food available
to them. Wherever deer populations are high, so are those of cougar.
Although no reliable population estimates are available, cougar
sightings are most frequent in the southern and eastern parts of
the Columbia Basin, where ungulate populations are the highest.
When deer populations crash, as in the winter of 1996-97, their
predator's populations follow, with a seasonal lag. Immediately
after a deer population crash, cougar populations are still high,
and the big cats are hungry. Then, cougars will hang around rural
human habitations where pets and livestock offer easy prey.
They stalk their prey, primarily
deer but, depending on what is abundant at the time, anything from
mice to moose. Cougars pounce on the shoulders and necks of their
prey as they come upon them from behind, killing them within two
or three jumps or letting them go if they escape. An average adult
male has an appetite for 14 to 20 mule deer per year (Spalding,
1994). Although cougars are not normally aggressive towards people,
pets or livestock, a sick, orphaned or starving cougar will attack.
A healthy cougar is naturally curious and will sit and harmlessly
watch people working or playing for hours. Travelling through cougar
territory is usually safe, although the cougar knows you are there
and may watch or even follow you (Spalding, 1994). Recent attacks
in the Columbia Basin may have been from animals unable to find
food due to the low deer populations from the harsh 1996-97 winter.
Cougar
Conservation Issues
Cougars are an integral part of
the mosaic of BC's wildlife. They are important as regulators of
their major prey populations and as a source of outdoor recreation
for hunters and non-hunters, alike. Cougars are not the limiting
factor in regulating prey-populations; hunting and environmental
conditions have a greater influence on deer, moose, elk, wild sheep
and goats. In the long run, cougar do prevent the prey-populations
from exceeding the capacity of the land to support them, as well
as culling out sick, starving and weakened animals. They also constantly
redistribute game herds over their winter ranges because deer, for
example, will move a short distance away from the place of a kill
to continue their grazing.
More
Information on Cougars
http://wlapwww.gov.bc.ca/wld/
BC Environment, Lands & Parks information on cougar.
Wolf
Like the cougar, wolf populations
are limited by hunting pressure and prey availability. Wolves are
present throughout the mountainous areas of the Columbia Basin,
although in low numbers since early in the area's settlement period.
Wolves were considered "vermin" and shot on sight until
recently. They also fetched a high price for fur and a bounty from
provincial programs aimed at livestock protection. They are now
a "game" animal to which hunting limits and closed seasons
apply. With fur out of favour and the bounty long since abandoned,
wolf populations now follow the fluctuations of their prey populations:
ungulates (deer, moose, elk) and smaller game. No reliable estimates
of wolf populations are available for the region, but the number
of recent sightings suggests that they are still widely distributed
and possibly poised to make a comeback. The disastrous winter of
1996-97, which decimated ungulate populations, must also have hurt
the wolf populations.
Wolf
Conservation Issues
Recreation and industry have moved
into wolf territory. Logging and mining roads provide access to
hunters, and snowmobiles ease winter access. Hunting and harassment
of wolves and their prey, especially caribou on their winter range,
are the two most pressing management issues. These are being addressed
through public information programs and consultation with recreational
companies and groups.
Wolf population control programs
have not been necessary in the Columbia Basin in recent years as
natural population controls, including hunting by humans, have been
adequate to maintain a suitable balance.
References
- Large Carnivores
- Boulanger, John. 1996. DNA mark-recapture
methods for inventory of Grizzly bear populations in British
Columbia: Elk valley (1996) case study. Ministry of Environment/FRBC
report, BC, Canada.
Chester, J.M., 1980. Factors influencing human-grizzly
bear interactions in a backcountry setting. IN C.J. Martinka
and K.L. McArthur (eds.), Bears - their biology and management.
Papers of the Fourth International Conference on Bear Research
and Management. Kalispell, Montana, February, 1977. Bear
Biology Association Conference Series No. 3., pp. 351-357.
Hamer, J.D.W., 1974. Distribution, abundance and management
of the grizzly bear and mountain caribou in the Mountain Creek
watershed of Glacier National Park, British Columbia. M.Sc.
Thesis, Univ. of Calgary.
Harding, L.E., 1976. Den-site characteristics of
arctic coastal grizzly bears (Ursus arctos L.) on Richards Island,
Northwest Territories, Canada. Can. J. Zool. 54(8): 1357-1363.
Harding, L. 1985. A delicate balance: the wolf control
program in British Columbia. BC Outdoors 41(3): 22-33.
Halko, Robert. 1996. Elk Valley Bear Inventory Project
Report. Ministry of Environment/FRBC report, BC, Canada.
Halko, R. 1998. Southern East Kootenay Bear Inventory
Project Report: 1997. Ministry of Environment/FRBC report, BC,
Canada.
Lofroth, E.C., 1994. Grizzly Bears in British Columbia.
British Columbia Ministry of Environment, Lands and Parks.
McCrory, W., S. Herrero and P. Whitfield, 1985. Using
grizzly bear habitat information to reduce human-grizzly bear
conflicts in Kokanee Glacier and Valhalla Provincial Parks,
B.C. Presented at the Grizzly Bear Habitat Symposium, Missoula,
MT, April 30-May 2, 1985.
Middleton, D., 1999. The Bear Den.
Mowat, G. and Strobeck, C., 1998. Estimating Population
Size of Grizzly Bears Using Hair Capture and DNA Fingerprinting
in the Central Selkirk Mountains of British Columbia. Final
Report for Slocan Forest Products, Pope and Talbot Ltd., and
Ministry of Environment, Lands and Parks, Nelson, BC. 16 pp.
Mowat, G. and Strobeck, C. 1998. Estimating Population
Size of Grizzly Bears Using Hair Capture and DNA Fingerprinting
in the Central Selkirk Mountains of British Columbia. Ministry
of Environment/FRBC report, BC, Canada.
Nagorsen, D.W., 1990. The mammals of British Columbia:
a taxonomic catalogue. Memoir No. 4, Royal British Columbia
Museum.
Spalding, D.J., 1994. Cougar in British Columbia.
British Columbia Ministry of Environment, Lands and
Parks.
Simpson, K. 1987. Impacts of a hydro-electric
reservoir on populations of caribou and grizzly bear in southern
B.C. Wildlife Working Report No. WR-24, Ministry of Environment,
Nelson, B.C. 40 pp.
Simpson, K. and B.N. McLellan, 1990. Wildlife habitat
inventory and management planning in Mount Revelstoke and Glacier
National Parks. Report prepared for Canadian Parks Service,
Revelstoke.
Vroom, G.W., S. Herrero and R.T. Ogilvie, 1980. The
ecology of winter den sites of grizzly bears in Banff National
Park, Alberta. In C.J. Martinka and K.L. McArthur (ed.s),
Bears - their biology and management. Papers of the
Fourth International Conference on Bear Research and Management,
Kalispell, Montana, February, 1977. Bear Biology Association
Conference Series No. 3., pp. 321-330.
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Other Wildlife Subjects
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