Black Bear Attacks in the USA/Data
Exposure
| Exposure Level | Number of Days | Daily Encounter Rate | Injury Given Encounter | Fatality Given Injury |
|---|---|---|---|---|
|
1 day |
1 |
0.00000955 |
0.012 |
0.025 |
|
10 days |
10 |
0.00000955 |
0.012 |
0.025 |
|
100 days |
100 |
0.00000955 |
0.012 |
0.025 |
The number of days represents the exposure duration in black bear country. The daily encounter rate (0.00000955 or 9.55e-6) is calculated as 1010 close encounters (estimated using similar proportion as grizzlies for black bear interactions) divided by 105.6 million visits in Yellowstone from 1991-2022, adjusted for higher black bear interactions (10,081 total). Injury given encounter (0.012) is 5 injuries divided by estimated 410 close encounters. Fatality given injury (0.025) is based on 2-2.5% mortality rate in black bear attacks. These values are constant across rows as they represent base rates.
- [bear and American black bear interactions with people in Yellowstone National Park]
- [review of upper limb injuries in bear maul victims]
Location
| Location | Odds Ratio |
|---|---|
|
Alaska |
3.0 |
|
Appalachian Trail States |
1.4 |
|
Other Bear-Populated States |
1.0 |
|
Non-Bear Area |
0.0 |
Odds ratios are scaled relative to other bear-populated states (baseline = 1.0) based on attack frequency and population exposure. Alaska has higher odds (3.0) due to high black bear density and 3.5 times more fatal attacks than lower 48 states. Appalachian states have moderate odds based on documented attacks.
Activity
| Activity | Odds Ratio |
|---|---|
|
Hiking/Camping with Dog |
2.0 |
|
Hiking/Camping without Dog |
1.0 |
|
Other Outdoor Activities |
0.8 |
|
Indoor Activities |
0.2 |
Odds ratios are scaled relative to hiking/camping without dog (baseline = 1.0). Hiking/camping with dog has higher odds (2.0) as over 50% of 92 black bear attacks involved dogs. Other activities have lower odds.
Season
| Season | Percentage of Attacks | Number of Months |
|---|---|---|
|
Summer |
50 |
3 |
|
Other Active Months |
50 |
6 |
|
Hibernation Season |
0 |
3 |
Percentage of attacks by season is estimated from North American data, with summer peak. Number of months for normalization, assuming 9 active months.
Precautionary Measures
| Precautionary Measures | Risk Reduction Multiplier |
|---|---|
|
Bear Spray and Food Storage |
0.02 |
|
Bear Spray Only |
0.08 |
|
Food Storage Only |
0.5 |
|
No Precautions |
1.0 |
Risk reduction multiplier represents the remaining risk after precautions. Bear spray alone reduces risk to 0.08 (92% effectiveness). Combined with food storage assumes near-complete reduction (0.02). Food storage alone reduces to 0.5.
RiskModel: Black Bear Attacks in the USA/Data:encounter_risk
Calculation: daily_encounter_rate * exposure_days * location_odds_ratio * activity_odds_ratio * (season_percentage_attacks / season_months) / (100 / 9) * precautions_risk_reduction
Content: Your chance of having a dangerous, close encounter with a black bear is {{One_In_X|{result}}}
RiskModel: Black Bear Attacks in the USA/Data:injury_risk
Calculation: daily_encounter_rate * exposure_days * location_odds_ratio * activity_odds_ratio * (season_percentage_attacks / season_months) / (100 / 9) * precautions_risk_reduction * injury_given_encounter
Content: Your chance of being injured in a black bear attack is {{One_In_X|{result}}}
RiskModel: Black Bear Attacks in the USA/Data:fatality_risk
Calculation: daily_encounter_rate * exposure_days * location_odds_ratio * activity_odds_ratio * (season_percentage_attacks / season_months) / (100 / 9) * precautions_risk_reduction * injury_given_encounter * fatality_given_injury
Content: Your chance of being killed in a black bear attack is {{One_In_X|{result}}}
Note that risks are averages and vary by subgroup, geography, or circumstance.
Generated by an AI assistant.