Yellowstone Grizzly Bears
Ecology and Conservation of an Icon of Wilderness
Introduction
(White, Gunther, Manen)
Tough transitions away from Jellystone
Currently 1 attack per year
5 Property damage claims per year
All numbers are from 2017
150-200 YNP Bears
500-600 GYE Bears
350 and 1000 in 2022
Chapter 1: The Population
Attributes, Behavior, Genetics, Nutrition, and Status
Attributes
Ursus arctos is widely distributed across the northern hemisphere
Concave face
3 inch long claws
Prominent shoulder hump (3 feet in height)
Omnivores dentition
Lumbering and plantigrade
Vision similar to humans
Remarkable spatial memory
Linked to scent
Weights
Males 265-720
Females 200-440
Full grown at 5
Continue to grow after
Males reach max after females
Cubs of the Year (COY)
.9-1.4 lbs
10-20 lbs (10 weeks)
128-139 lbs (1 Year)
187-217 lbs (2 Years)
Behavior and Range
Use all ecosystems in GYE
Movement influenced by:
Age
Sex breeding
Food quality and quantity
Human disturbance
Bear avoidance
Denning
Mating in May - July
Male competition
Promiscuous
Litters by 1 or more fathers
Denning
Enter dens October - December
When food is limited
4-6 months in hibernation
Order
Pregnant females
Females with cubs
Subadults
Adult males
*Opposite order of emergence
Weaned at 2 years (Typically)
Typically solitary
Aggregate at carcasses
Large males hold the highest social rank
Nutritional Ecology
Generalist Diet
175 species of plants, 37 invertebrates, 34 mammals, 7 birds, 4 fish
257 Total species
Short digestive tract
Poor plant digestion
Eat succulent plants that are low in fiber
Favorite foods
Army cutworm moths
Whitebark pine nuts
Cutthroat trout
Ungulates
60% Plant matter & 40% Meat
Population Dynamics
<250 bears in mid-1970s
Increased human conflict
Low reproductive rate
1975 listed on the Endangered Species Act
Efforts to reduce conflict
Habitat protection
Denial of food sources
Education
Human management
Annual 4%-7% increase through 1980s
Interagency Grizzly Bear Study Team
Monitors 14.3 million acres
690 Bears (2017)
Current estimates of 50% more
87% of deaths were human-caused
10% of the population per year
Ecological Niche
Influence on the Structure and Function of an Ecosystem
Limited elk numbers
Influencing distribution of predators and scavengers via competition
Distributing nutrients in an ecosystem
Trout nutrients to the land
Adaptive Capabilities and Genetics
Traits often embody wilderness
Influenced by isolation and genetic drift
Stable genetic diversity since 1985
Low inbreeding (.2%)
Human Bear Interactions
Human food was a major part of their diet before the 1970s
150 property damage events each year
50 bear attacks per year
Few negatives for bears in roadside interactions
People tolerated to 30 yards along roadsides
Conclusions
Human-grizzly interaction will be the driving force in the long-term grizzly population
Chapter 2
Historical Perspectives
From persecution to food dependency to recovery as wildlife
Population Decrease and Protection
100,000 bears pre-colonization
98% loss in viable habitat
Poor historical accounts of GYE bears pre-park
Large slaughters in the 1870s brought numbers way down
1883 hunting ban
1886 US Calvary takes control of the park
1894 Lacey Act
All helped to slow the killing of bears
Food Conditioning and Sideshows
Banned in 1902
Not enforced
40 bears at each site
West Yellowstone dump
Rabbit Creek dump
100 bears at Trout Creek Dump
Short visitation season
Few interactions with bears preparing for or coming out of hibernation
Restoration as Wildlife
1959 first grizzly study
John and Frank Craighead
Cautioned that closing dumps would lead to a decrease in the bear population
1969 Natural Science Advisory Committee closed the dumps
Craigheads strongly opposed
NPS pulled a 1971 research permit
Educated campers about food storage and provided bear hangs
Fewer injuries over time
229 lethal bear removals from 1969-1971
½ of the Grizzly population
1975 listed on ESA
Frustrated traditional ranchers and miners
Recovery and Range Expansion
Bear killing is unpopular
Interagency Grizzly Bear Committee aimed to lower grizzly mortality
Manage motorized access
Garbage management
Food storage
Reduced sheep grazing
Pacher ID
1990- 2004 4,000 bear jams
Higher visitation
Higher population density
People management vs bear management
Bear numbers up 4%- 7% per year (1983-2001)
Range up by 50%
2007 population deemed recovered
Overturned in 2009
Upheld in 2011
USFW recommended delisting in 2016
After analyzing whitebark pine mortality
Cultural Importance
Prominent indigenous role
Ceremonies and symbolism
Treatment of bears similar to the treatment of native communities
Tribes generally oppose delisting
See grizzly hunting as an infringement on spiritual rights
People generally see bears as a valuable amenity
Conclusions
Bear and human management needed
Collaborative efforts are more effective
Visitor management a challenge
Other threats:
Habitat encroachment
Climate change
Invasive species
Delisting
Chapter 3
Reproduction, survival, and population growth
Introduction
GYE is an isolated population
Population-based solely on reproduction and survival
Reproductive Cycle
1 Breeding season per year
Receptive for 17-45 days
May 18- July 11 (63 days season)
Males follow females and create short-term pairs
Bonds last a few days
Successful strategy for the largest males
Delayed implantation
Fertilized embryo remains as a blastocyst
Implants in late November
60-day gestation
Late January- early February parturition
Newborn Cubs
8 inches
1.1 lbs on average
Smallest young: mother body size ratio in all mammals
<1%
Humans ~5%
Weaning
2.5 years in GYE
4.5 years in inland Alaska
Mixed-age liters are rare but possible
Females may only produce 4 or 5 liters in lifetime
14-year replacement time
Reproductive Rates
Fecundity
Numbers of female cubs per female per year
♀cubs/ ♀bears/ year
*Data from long-term capture studies
Reproductive rates
Age at first reproduction (4-10 years)
Litter size
Cub survival
Interbirth interval
Age of senescence
Does this happen?
First reproduction
Avg. 5-6 years
10% age 4
30% age 5
56% age 6
Litter Size
1-3 typical
4 occasionally
Average 1.7- 2.5 in 17 studies
Radio telemetry data studies
8 4-COY litters in 1983
6 since
Result of older birth ages
Food availability
Whitebark Pine mast years
More 3 cub litters
Fewer 1 cub litters
Recent studies show no correlation between a decline in stands and birth numbers
Similar relationships may exist for other food sources
Population density
More bears mean fewer cubs
Maternal Care and Cub Growth
Newborns blind and hairless (altricial)
Mothers need fat reserves
< 20% body fat means no COY
Nurses while mothers hibernate
Avg. 12.5 oz of milk per day
3.5 oz per day of growth
Twins
4.4 lbs at 30 days
8.8 lbs at 60 days
22 lbs at 90 days (11 lbs for triplets)
July and August bears ~ 55 lbs
Denning at 115 lbs
Yearling 110-137 lbs
2.5 Year olds 194-220 lbs
Survival
A major factor affecting the population
Adult female survival is especially important
Survival strongly tied to human factors
Roads, developments, livestock, and attractants
Max age in YNP
Females late 20’s
Males mid 20’s
Research goals
25 collared females
A representative group of males
Mortality events
No movement in 4 hours
Investigated within 2 weeks
95% yearly survival for females
87% for males
COY Survival
55% currently
64% in 1983
Yearling survival
54% currently
82% in 1983
Causes of Mortality
8% natural death
7% undetermined
Avalanches, injuries, conspecifics, prey, old age, starvation
85% Human-caused
Poaching down from 20% -5%
30% self defense
25% by car collisions
20% depredation
Mortality trends driven by range expansion
Included more hunter encounters
Human mortality by area
17% YNP
33% in the Grizzly recovery area
85% outside of GRA
Population Growth Density
1970 estimate <250 bears
2000-2017 > 690 bears
Equal sex ratios
By age
59% adult
11% subadult
30% cubs and yearlings
Growth Rates
4.2%- 7.6% (1983- 2001)
.3% - 2.2% (2002- 2011)
Lowered cub survival
Higher density-dependent factors
Lowered cub survival
Lowered reproduction
Lowered adult survival
Higher rates of infanticide
Chapter 4
Nutritional Ecology
Introduction
A similar digestive tract to humans
6-8 hour digestive process
Meat is more digestible
90% digestibility for elk and trout
40% for dandelion and clover
These are 75% digestible by elk
Compensate by increased volume
Especially with leaves and roots
Choose nuts and berries when possible
Driven by the need to gain fat
Mothers-to-be particularly need fat
4-5 months of no food and nursing
Milk 18% fat and 6% protein
(humans 4% and 1% by comparison)
20%-30% of body fat goes to bear cubs
The fatter the better
No ill effects from obesity
Seasonal Diets, Dietary Breadth, and Resiliency
Grizzly kill an elk calf every other day through June (in Lamar Valley)
Every 4-5 days along Lake Yellowstone
70% of predations at dusk
Males are more carnivorous than females
Feed on elk every 4 vs 14 days through summer
½ of the carcasses taken by wolves
37% of bears now visit spawning trout streams
Down from studies 1997-2000
70% less trout consumed
No longer considered an important part of bear diets
May have switched to greater elk predation
Ants are the primary food in July
Bison carcasses from Rut Kill available from mid-July through August
Autumn food sources
Whitebark pine
Berries
False truffles
Ungulates
Rut, wolves, hunters
Whitebark pine
Down since 1990s
25% of the diet in 2009
52% fat and 20% protein
⅓ of grizzlies have no whitebark pine in their home range
Other foods in fall
Ants, biswort root, buffaloberry, clover, false truffle, horsetail, pondweed roots, yampa, vaccinium berry, sweet cicely root
False Truffle
Grow at the base of lodgepole
Not edible by humans
Only female grizzlies typically eat them
Able to smell them below the ground
Bears select for high protein and high carb diets
Berries make up 85% of diet where whitebark pines have decline by > 70%
Bears continue to adapt
Meat
45% male diet
38% female diet
32% 1,000 years ago (atomically calculated via grizzly bones in packrat dens)
3% of diets in Glacier and Denali
Body Mass Gain and Body Condition
Males 457 lbs (416 in June)
Females 296 lbs (257 in June)
3 lbs per day weight gain in hyperphagia
25% body fat throughout year
30% at hibernation
Army Cutworm moths
.007 oz
65% fat
178 moths per meter
40,000 moths per day
20,000 calories per day
31 known moth feeding sites
Lawn and agricultural pests
Killed using pesticides
Concerns over lack of whitebark pine trees
Hibernation
Adaptation for food scarcity
Do not eat, drink, urinate, or defecate
Reduced energy use (70% savings)
99.7% of protein recycled
Non-lactating only!
Lowered heart rate
80-90 bpm → 8-19 bpm
Lowered temperature
100℉ → 91℉
Lowered breath rate
8-19 bpm → 6-10 bpm
Can awaken quickly
Heart rate can jump to 100 bpm in one second
Lose 15% to 30% of body weight in winter
Conclusions
Highly food driven
Endangered by human activities
Climate change
Increasing competition with black bears
What are the limits of adaptation?!
Chapter 5
Movement and Occupied Range
Introduction
Ability to move great distances and use diverse habitat
Use local and seasonal foods
Movements vary with age and season
Home range size depends on habitat productivity
GYE home ranges are very large
Population density influences home range size and movements
Seasonal Movements and Strategies
Not considered migratory
Make recurring seasonal movements to access food sources
Post emergence
Low elevation
Snow free areas
New vegetation and winer kill carcasses
Little movement
Less for cubs and mom
Remain close to den
Spring → Summer
Elk calves important food source
Move to progressively higher elevations
Male bear movement peaks May- June
Highly crepuscular
Females active midday in hyperphagia
Autumn hyperphagia
Bear movements are direct reflection of available resources
Average home range size
Females 62- 66 square miles
Males 154- 197 square miles
Annual and Lifelong Home Ranges
Area traversed by an individual in its normal activity
Annual = accumulation of all seasonal movements
Home ranges often overlap
Larger than coastal bears, smaller than Alaskan interior grizzly
Dispersal and Range Expansion
Differ for male and female bears
Females establish adjacent ranges
Males disperse many miles
Reduce inbreeding
Young males responsible for range expansion
Twice as far as 15 years ago
Dispersal as far as Boulder, CO
Conclusions
As ranges continue to expand so does human conflict
Chapter 6
Ecological Niche
Introduction
Effects on other species not well documented
Generalist = large niche
Flexible behavior and niches
Predation
30% of meat is actively killed
46% moose
43% elk
4% bison
Elk calves vulnerable for first 15-30 days
Trout (May- July)
70% fewer trout being consumed
Lake trout
Whirling disease
Prolonged drought
Trout population at 10% of historic numbers
14 Small mammals consumed
Pocket gophers and voles
Low annual variation
Size dictates prey
Larger animals hunt larger prey
Seasonal components as well
Predation affects elk recruitment
38% fo elk deaths in first 30 days
.55 calves per day
Varied wildly before wolves
Scavenging
Can detect a carcass greater than 9 miles away
4-5 bears per carcass regular
20 bears have been documented
Scavenge gut piles left by hunters
Observed moving out of YNP for elk hunt
2.5 times more common outside of YNP during hunting season
Increased human conflict
Often steal kills
Stole 7 of 19 lion kills in one study
Mountain lions have 17%~ 26% of kills stolen
Global warming creates fewer winter kills
Offset by predator concentration
Interactions and Competition
Limited competition with herbivores and carnivores
Differ in seasonality
Direct competitors with black bears
Black bears become more diurnal when in proximity to grizzly bears
New Research
Kinship recognition
2 cases of cub adoption
Exhibit hierarchy at food resources
1 elk carcass yields ~300 lbs of food
8.5 days of food
Potentially 50 lbs of weight gain
1 bison carcass yields ~ 1,000 lbs of food
28 days of food
Potentially 160 lbs of weight gain
Food Competition
Goal is to eat all the food!
Exclusion of competitors
Higher competition with increased bear density
Mom with COY have 37% less energy available (lowest socially)
Outcompete black bears
Food Webs
Omnivore: Consumes foot at more than 1 trophic level
Stabilizing effect on food webs
Grizzly have many weak connections and a few strong
Red squirrels
90% of seeds (especially whitebark pines) are part of middens from squirrels
Important seed dispersers
Digging for roots affects soil health and plant production
Trophic Interactions
Redistribute energy and nutrients across the landscape
Omnivory prevents trophic cascade events similar to wolves
Chapter 7
Genetics and Adaptive Capabilities
Introduction
Historic range from Mississippi to California and Mexico to Alaska
Populations suffered as livestock grazing increased
Genetically isolated early on
Lowered reproductive fitness
Population drop after dumps closed
Half of individuals were killed
Population between 136-250 bears
Genetic Diversity
Slow rate of genetic decline over the past 100 years
No bottleneck effect seen
Lower diversity than european or coastal brown bears
Gene Flow and Population Structure
No immigration or emigration
50 years of collar data backs this claim
Northern Continental Divide Ecosystem is closest geographically
68 mile separation
Not very genetically related
No movement barriers within GYE
Readily cross roads
High translocation ability
Yaak Mountain population has most closely related bears
Genetic Structure Worldwide
Use mitochondrial DNA to determine clades
Many clades and Subclades worldwide (6)
Scandinavia
SE Alaskan Islands
Eastern Europe, Asia, interior Alaska
Japan, Banff, Lower 48
Tibet
Pakistan and Gobi Desert
Genetic Viability
Ne = Effective population size
Smaller than total population
Just breeders
100 → 450 bears (1982 → 2007
500 recommended for viability
Conclusions
More research is needed
Chapter 8
Human Bear Interactions
Decreasing awareness and increasing visitation
Introduction
Grizzly bears are at a 200 year high
Visitation is at an all time high
Many urban and international visitors
Increased need for
Safety infrastructure
Education
Staff
Human Bear Conflicts
Highly food motivated due to hibernation
Intelligent, behaviorally flexible, broad diet
Conflicts increase late summer and fall
2,497 conflicts (2002-2014)
~200/year
43% livestock related
34% property damage
14% Garden or hive damage
6% obtaining food
3% human injury
.2% death
Most livestock conflicts on Forest Service Land
Most human conflict on private land
Land owners reluctant to adapt
85% of bear deaths human caused
37% mistaken identification
21% removals
14% depredation
8% vehicle strikes
6% poaching
Human Bear Encounters
1991 → 2015 (5,578)
57% neutral
35% fleeing
3% curious
1% stress
4% bluff charges
<1% attack
No attacks in human areas
More common off trail than on trail
Grizzly Bear Attacks
Safety vs Wilderness
GTNP 1 attack per 3 years (7 total)
57 million visitors
1 in 25 million chances on tour
1 in 2.7 million chance total
Hunters required to carry bear spray
Yellowstone
1.1 attacks per year (100 million visitors)
Only 4 front country injuries
7 Deaths in YNP history
1 unidentified bear death (could be black bear)
8 more death in surrounding national forests
Visitor Compliance
High consequence low probability
Bear Spray
52% of backpackers
14% of day hikers
<1% of boardwalk hikers
Conclusions
Bears that obtain food become a threat to humans
People should remember their actions have greater consequences
Chapter 9
Bear Viewing
Habituation, Expectations, and Economics
Introduction
Adaptable and amenable to living with people
Education and bear proof structures
Habituation
Habituation is a product of adaptability
Waning of flight response
Differs from food conditioning
Livestock predation and garbage
Increased human conflict
Results in the death of the bear
Habituation is site specific
A bear will respond differently on the roadside vs in the backcountry
Yellowstone National Park
First roadside bear 1910
Panhandling bears common 1920’s to 1970’s
By 1979 most conditions bears had been killed
1980 bear jams reappeared
Natural diet
Bears hazed away from roads
1990 started managing people not bears
1990- 2014
12,386 bear jams
0 attacks
Few issues
5 vehicle strikes on people
Expensive and labor intensive
3,000 person hours per year
80% of jams attended
Roadside bears decrease in years with good whitebark pine nut crops
Bear viewing important for local economy and conservation
Grand Teton National Park
Bears rare before 2000
Recent range expansion
2004 first roadside bear
Followed the example set by YNP
2007 Wildlife Brigade
7 months per year
3 paid positions, 22 volunteer, 1 intern
Food patrol, education, management
2008- 2017
~2,600 incidents
50% grizzly jams
Jams fluctuate based on number of COY
Fluctuate with berries
Offspring of habituated bears more likely to be killed
GTNP bears more likely to die than those in YNP
Positives and negatives of habituation
Habituated bears allow otherwise unused home ranges to be occupied
Increased acceptance of bears
Increased opportunities for appreciation
Increased teaching opportunities
Less aggressive towards people
More traffic congestion
More people behaving badly
More likely to eat human food
Managing Habituation Depends on Circumstances
Reduction of human conflict
In popular areas (the parks)
Habituationnot tolerated
Private lands, Glacier National Park
Visitor Expectations and Economics
Only 3 parks in the lower 48 have grizzlies (North Cascades is close!
YNP 4.2- 4.9 million visitors
97% Geyser viewing
88% Sightseeing
81% Wildlife viewing
65% want to see a bear
State of bear matters?
49% don’t care about habituation
59% don’t care about collars
10% wouldn’t come without bears
Economy
2016 - 524.3 million dollars wildlife viewing
8,156 Jobs
Bears worth 10 million per year
155 jobs
Visitors willing to pay extra $40 to see a bear
Conclusions
Visitation expected to continue growing
Have been adaptable so far
Must have some limit
Need more budget to continue
Must continue to manage people
Food storage
100 yard rule
Chapter 10
Current Management Strategies
Introduction
Public land management agencies
US forest service- wise management
BLM
US Fish and Wildlife
ID, WY, MT
National Park Service- preservation
People most accustomed to NPS management- human restriction
Outside of NPS more potential conflict
Grizzly survival
Lowered road densities
Lower rates of elk hunting
Management of Grizzly in National Parks
3 Zones
Developed areas (<1%)
Road corridors (<1%)
Backcountry/ WIlderness (99%)
Food rewards are rare
Backcountry camping in YNP
301 campsites
<2% dispersed camping
Food storage and hangs provided
70% on foot, 17% horse, 13% boat
40,000 backcountry visits
30,000 nights in Grand Teton National Park
Bear Spray and containers required
No hangs provided
Bear management areas
Seasonal closures
Restricted travel
21% of park affected
Goals
Minimize human bear interactions
Prevent displacement of bears from prime food sources
Decrease chance of attack
Bears 2x more likely to use areas without people and miss important food
Totally avoided areas 437 yards from backcountry sites
Sites within 550 yards of critical food sources closed seasonally
Messaging
Aimed at visitors before and after park entrances
Only 3 deaths since 2011
Only 14% of day hikers carry bear spray!
Management in National Forests
Grizzly value vs Resource value
Timber harvest
Bears occur in higher densities in mature forests
Not lodgepole pines lol
GYE Forests
Low diversity
Slow growth
Variable economic value
Most economic harvest
Build spur road
Clear cut
Checked at 3-5 years
Replanted at 8 years
Thinned at 20-25 years
Increases foraging
Loss of plant cover and soil instability
Increased grasses, herbs, and berries
Effects generally negative
Livestock grazing
Heavy impact early on
Currently livestock have minimal effect on vegetation structure
Decreasing depredation
Regulate stocking rates, timing, and duration
No new permits in GRA
Phasing out of sheep and cattle allotments
Still increasing from 4% to 13% in 2017
80% of depredations on public land
Mostly males in summer
Relocation ineffective
Carcass removal is effective
Limit riparian grazing to winters only
Mineral extraction
Toxic runoff
roads/ encroachment
General Mining Act 1872
Con mitigate not refuse
Sport Hunting
43% of bear mortality (2002- 2014)
Hunter education
Bear spray, camping, quick retrieval
Wilderness Act of 1964
Nothing motorized or mechanized
“A wilderness, in contrast with those areas men and his own works dominate the landscape, is hereby recognized as an area where earth and its community of life are untrammeled by man, where man himself is a visitor who does not remain”
Low conflict areas
Conflict Management
Federal
Conserve biodiversity
Sustain native populations
States
Primary management of wildlife
Management on State and Private Lands
Prevent bears from obtaining human food!
Community efforts
Trash cans, food storage, electric fences
Many private landowners reluctant to or cannot incur costs and lifestyle changes
Complicated by range expansion
Management decisions favor landowners
Must be done in timely manner
Grizzly Conservation Strategy
Protected in 1975 under ESA
Habitat loss
Habitat alteration
Potential/ proposed removal
Always managed by “Conservation Strategy for the Grizzly Bear in the Greater Yellowstone Ecosystem”
State, federal, tribal, and communities
Regulatory authorities
Policies
Monitoring
Limited to 9,210 square miles recovery area
59% forest, 39% park
Conserving a recovered population
Adequate numbers
Wide distribution
Balanced reproduction and mortality
Target number 674 bears
Are bears inside or outside GMA?
Inside subject to “conservation strategy”
Outside state or federal policies apply
Bears removed for causing significant risk to people or irresolvable conflict
Information and Education Working Group
Conclusions
Main decline due to human fatalities
Goal is to manage those fatalities
Chapter 11
The Future Considerations and Conservation
Introduction
YNP is critical habitat
Proving grounds for bear-human conflict reduction
Commitment of many for sustainable wildlife populations
Key Points
Bears need vast remote places
Sustainable populations require many hundreds of individuals across broad areas
9,210 square miles primary conservation habitat
Reduce human related mortality
Development
Roads
Livestock grazing
Low in National Parks
Land development outpacing population growth in many areas
Low density rural ranches
Preserve land and connect habitat
Keys to long term viability
Prevent bears accessing human food
Education, everyone has a personal choice
Some habituation inevitable
High visitation to national parks
Allow bear to access more forage
Not tame- maintain 100 yards
Habituated grizzly offspring more likely to cause conflict
Hazing of bears on roadside happens when humans cannot be managed
Sustained recovery contingent on support and human tolerance
Still #1 cause of death
Restriction on some activities
Increased education
Continued research is a must
Issues and Considerations
Great success story
Various opinions on
Management
Role on landscape
Status
Increasing abundance and distribution
Need large expanses and low death rates
Increased education need
Human habituated areas always a challenge
Human- induced mortality
Greater awareness leads to greater tolerance
Proactive human lifestyle
Sport hunting
Can happen if removed from ESL
Most controversial issue
Concern over harvest of known bears
States committed to annual meeting
“Conservative harvest” would have minimal impact
Research!
Population dynamic
Dispersa, recruitment, and survival
Regulated, monitored, adaptive management
Climate warming and food resources
Flexibility to change diet
Compensated for climate changes
Dryer (20%) leads to more fire potential
Positives?
More berries
Fish restoration
Genetic isolation
Genetically stable, little inbreeding
Low genetic diversity
Would benefit from gene flow
68 miles from continental divide population
Increasing visitation
Food storage since 1960s
4.9 million visitors per year
Lessen displacement and habituation
Blunt messaging
A fed bear is a dead bear
Safety precautions
Bear spray
Group travel (3 or more)
Make noise
<30% of backcountry travelers carry bear spray
A bear doesn't care
Photography and viewing ethics
Believe they have special relationship
Increased habituation (from constant stalking)
Decreased distances bears will tolerate people
Longer bear jams
More susceptible to food conditioning
Higher mortality
Photographer set behavior examples
Public engagement
Presentations and discussions
Independent reviews of proposals
Increased public confidence
Consultation of tribes
Conclusions
Interagency cooperation is a must
50 year strong foundation
Continued conservation determined by human values, behavior, and decisions
Grizzly supremely adaptable
Grizzly Bear Facts!
2016 Population: 615- 764
Average home ranges:
Subadults: Males: 197 square miles Females: 59 square miles
Adults: Males: 155 square miles Females: 66 square miles
Females with cubs 62 square miles
Lifespan: 20-30 years
Molt each year
Blue eyes as babies
Bears sense of smell is 2,100 times better than humans
Vision equal to humans
Better at night
Ultrasonic hearing 16 hertz or higher
34”-38” inches at shoulder
6’8” standing
58”-65” length
Average weight
413 Males
269 Females
Max weight
715 Males
436 Females
Speed: 35-45 miles per hour
2.5- 5 times stronger than humans
Bite Force
2,750 psi
Humans 975 psi
Claw length
2- 5.6 inches
Body Temp
98.6- 100.4 degrees
88-86 during hibernation
Breathing Rate
6-10 BPM
1 BPM during hibernation
Heart Rate
40-50 BPM
8-19 BPM in hibernation
42 Teeth
224 bones (+1 in males)
Demographics
50:50 sex ratio
20% cubs
11% yearlings
16% subadults
53% adults
Promiscuous mating
mid-May through mid-July mating system
Delayed implantation
Birth late January or early February
Dens
91% excavated
6% natural cavity
3% snow
November entry
171 days for females and COY
151 days for females and subadults
131 days for males
March- April emergence
Hibernation
Metabolism down 25%
Heart rate down 20%- 45%
Body temp down 2-8 degrees C
No cyclic arousal
15-30% weight loss
5 or 6 at first reproduction
1-4 cubs per liter
Average 2
2.5- 3.5 years between liters
.3 female cubs per female per year
Survival rates
55% cubs
54% yearlings
95% adults and subadults
85% human caused deaths
15% natural
Maternity
Care 18-42 months (30 average)
3 pairs of functional nipples
Milk
30% fat
15% protein
2.3 kcal/gram
Cubs open eyes at 21 days
Weaned at 24 weeks
Females senescence after 25 years
History of YNP Bears
1806: Lewis and Clark encounter 2 bears in Montana
1837: Osborn Russel encounters 1 bear near Yellowstone Lake
1848: Gold discovered
1872: YNP established
1884: 40 million cattle, bears killed to make room for stock
1886: Hunting bears in YNP banned
1888: 1st Grizzly attack reported
1890: Grizzly feeding at garbage dumps
1891: 1st habituated bear killed
Forest reserve act
1st step in forest preservation create a buffer for YNP
“Picnic ground for bears” opens
1892: 1st death by grizzly
1897: Organic Act. Administration of forests
Teton forest created
1902: Hand feeding bears “outlawed”
Teddy Rosevlet adds 5 million acres to national forest
1905: National forests transferred to the department of agriculture from dept. Interior
Administrates 63 million acres
1913: USGS Robert Dale “all garbage should be buried or burned or fenced”
1916: Park Service created
1921: MT bans use of dogs to hunt bears
1931: Otter creek bear feeding ground popular. 1,500 seats, 600 car lot, 50-70 bears at a time
1 in 2,800 injured
1 in 1,000 property damage
1934: All dumps except Old Faithful and Canyon closed
1942: All dumps closed. Women killed at Old Faithful
1944: Olaus Murie only 10% of bear food was natural
1946: Idaho bans grizzly hunts
1948: Montana prohibits bear baiting
1959: Craigheads say garbage most important food source
1960: Modern bear management era
1963: Leupold report
1967: 2 women killed in Glacier NP
Montana requires separate black and grizzly tags
1969: A bear management policy and program for YNP
1970: Additional bear management guidelines. Food storage and bear proof trash cans
1971: West Yellowstone dump closed, moved, and fenced
1972: Backcountry camping in designated sites only
1973: Management removal slows
No bears killed by management
Grizzly study team founded
1974: Separate population estimates vary widely 136 low to 237-540 bears
1975: Bears on endangered species list
Wyoming and Montana close grizzly hunting
1977: Garbage not significant part of diet
1981: Population estimate 197
1982: 1st grizzly recovery plan
Seasonal activity restriction
1983: Interagency Grizzly Bear Committee formed
1984: Backcountry bear boxes installed
1986: Bear population up, 25 females and 48 new cubs!
1987: West Yellowstone outlaws bear feeding
Montana issues lifetime grizzly tag
1990: National forest require food storage and garbage storage
1993: Develop “Yellowstone Grizzly Bear Conservation Strategy”
1994: Increase food storage requirements
1996: Counts indicate carrying capacity for YNP bears
2001: Montana makes it illegal to intentionally leave bear attractants
2002: Plan to allow bear expansion into “biologically and socially suitable habitats
2003: Conservation strategy completed
2004: 4,400 domestic sheep removed from Absaroka
2005: Proposed rule to designate GYE grizzly separate population and remove from ESA
2007: Amended 1993 Recovery Plan Grizzly removed from ESA
2009: Missoula District Court vacates ruling, grizzly back on ESA
Increasing tribal cooperation
2010: USFWS restore full grizzly protection, repeals 2009 ruling
2011: Court rules whitebark pine reduction great enough threat to keep grizzly endangered
2013: 58 females, 126 cubs. Highest population recorded. Research shows whitebark pine has no significant impact on bears. (Compensate by diet shift). Bear density drive slowed growth rate over food resources.
2016: USFWS proposed to remove grizzly from ESA