A Century of Bear-Human Conflict in Alaska: Analyses and Implications

Research Conducted by:
Tom S. Smith, Ph.D. and Steven Herrero, Ph.D.

For the past several years Tom Smith and Steve Herrero have worked to construct a database of Alaska bear-human encounters spanning the 20th century. Currently, the database contains 500 incidents with 85 variables of information per incident, totaling over 17,000 individual data entries. The purpose of this research has been to promote bear conservation and human safety through minimizing conflict. Additionally, the principal researchers have desired to learn more about the patterns and timing of bear attacks in an effort to better understand underlying causes - an important step towards preventing future attacks. Research is yet underway and although analyses are tentative, we have desired to make findings to date available to the public and professionals who may desire to know this information for a variety of purposes. Comprehensive analyses of these data are forthcoming.

This is the distribution of bear attacks, by species, in Alaska. Note especially the non-random distribution with foci in Southeastern Alaska, Kodiak Island, the Kenai Peninsula and Denali National Park. One of the questions addressed by our research is what factors contribute to the non-random distribution of attacks?

This graphic presents the distribution of injuries inflicted by bears on humans. Again the pattern is very non-random and our research investigates factors that may explain this.

Primary Activity refers to the main reason for being in that location, whereas Secondary Activity refers to what the person(s) was engaged in at the time of the confrontation. For instance a person may be on the southern end of Kodiak Island to hunt deer (primary activity) but at the time of the incident he was simply sleeping in a tent (secondary activity).

We've presented attacks data from only the past 2 decades because reporting has been most consistent and concise during those times. One must ask if the message is finally getting out regarding safety in bear country when we see what appears to be a decreasing trend in the last several years. Only time will tell.

When the number of attacks is summed by 5 year intervals the outlook isn't as rosy as in the previous graphic. It appears that we're in a strong increasing trend, underscoring how much of an effect one can have on interpretating events simply by manipulating the data. This trend, however, is real and is consistent with an overall trend in North America of increasing problems between people and bears. The next graphic sheds additional light on this phenomenon, however.

Most bear biologists would agree that the frequency of bear attacks increases as a result of more people in an area. Alaska is no exception and you can see here that increases in population account for much of the increase in encounter rates. This is good news only in that it suggests that it is not that bears are getting more aggressive, but rather that if you increase the number of people (hence increase the bear-human contact rate) you will get more interactions.

It should be no surprise that grizzly/brown bears (Ursus arctos) are far more aggressive than black bears (Ursus americanus). This is borne out by experience throughout North America yet some bear safety books put the 2 species on the same level of aggressiveness. These numbers speak for themselves, however.

This table shows yet another way that Alaska bear encounter data can be presented. Here we see that females with young are quite often involved in conflicts, often surprised an protective of their young they strike back to neutralize the perceived threat.

By these calculations, the ‘average’ brown bear encounter is 13 times more dangerous than the average polar bear encounter and 22 times more dangerous than the black bear.

Be advised: the actual contact rates, proximity to human activity centers, pre-experience with people, bear age-sex cohort, individual bear condition and human activity modes are all confounding, yet important, factors in determining relative risk.

This is yet another way of looking at the relative risks associated with the 3 species of bears that inhabit Alaska. The text beneath the table provides some explanation of the data.

In considering all species and their encounter-attack rates, many are surprised by 2 facts: 1) polar bears have not lived up to the commonly held belief that they - above all other bears - will stalk and hunt down a human. Wouldn't we have more than 7 incidents total in 100 years if this statement were true? and 2) Brown/grizzly bears are incredibly more dangerous than the other 2 species. Don't lose sight of the fact, however, that we are focusing on the 'head of a pin' so to speak. Bear attacks are very, very rare phenonmen in Alaska, bearing testimony to the great pains these animals take to avoid humans. Sometimes, however, people leave them few choices and the unfortunate occurs....

This graphic demonstrates another little known fact: you can expect to encounter bears any month of the year in Alaska. There is never a time that you can forego appropriate conduct in bear country. We have experienced a bear inflicted fatality in every month of the year as well.

Consistent with reports elsewhere, the greatest contributing factor to bear attacks is surprise. As you browse the other categories note too that many of these causes could have been avoided had people alerted bears of their presence by making noise.

This graphic shows the percentage breakdown of each class of injury. We see here that nearly half of all encounters result in no injury at all. Of the 11% fatalities (56 deaths) brown bears were responsible for 86% (48).

Bears fare far worse in encounters with humans with nearly 33% being killed.

This subjective assessment attempts to place fault on bears or humans based on the details provided by the person involved. In some cases it is quite clear that even after people did everything right they still ended up in a face-to-face showdown with a bear. In other instances, however, it seems that people made bears offers that they just couldn't refuse, such as hiding a slab of bacon in their tent. In such instances who could conclude that the bear was at fault? Importantly, we see that a large number of bear-human encounters could have been avoided had people done the right things (e.g., store food properly, make noise while hiking through dense brush, not pushing bears when attempting to photograph them, etc.).

This graphic shows that single hikers are much more at risk of a bear encounter than any other group. It seems that bears size up the odds before engaging and if it is one-on-one they appear much more likely to mix it up with a person than otherwise. This highlights one of the most basic, and easy, things you can do to be safe in bear country: don't hike alone and have the group bunch up when traversing areas where the chance of meeting a bear is highest (e.g., near salmon streams, through dense brush, etc.).

In this final graphic, we can see that bear attacks have consistently occurred in habitats where visibility is poor, underscoring the fact that given a chance, most bears will avoid a conflict with people. What could have been done? Reroute around such areas as possible, make noise as appropriate, travel in groups of 2 or more, have deterrents - such as bear pepper spray - armed and ready.