A recent article from OregonLive.com (http://www.oregonlive.com/pacific-northwest-news/index.ssf/2011/12/bad_year_for_grizzlies_with_tw.html) addresses the inevitable increase of bear attacks in Yellowstone National Park. They report that two hikers were killed in two separate maulings and that a total of ten people were attacked across the West this year. A number of scientists seem to be baffled and apparently still have not made the connection between the conflict increases and the decline of the whitebark pines and the nutrient-rich cones that they produce, a favorite late-season meal for the bears. With very little info coming out about the whitebark situation (yet with plenty of articles reporting on the "baffling" nature of this heightened aggression in the bears), I decided to do a little digging. On the website for the Interagency Grizzly Bear Study Team, I found some interesting numbers and the numbers pretty much tell the story.
On their site, the IGBST maintains a list of bear mortality records in Yellowstone and whitebark pine health data from 2009 through 2011 and the correlation between the two is undeniable. 2009 shows one of the strongest whitebark pine production years on record and the bear mortality reflects that. In going through the records, I tried to eliminate attacks that could have been in defense of cubs or carcasses and focus only on those that were abnormal or in which bears raided campsites and residential areas in search of food. In all, 9 of these incidents were recorded, with one labeled as "cause unknown" and "under investigation". That's actually not as high of a number as it sounds and is probably fairly average, maybe just slightly above.
The change recorded in 2010 is very dramatic. Whitebark pine production is shown to be alarmingly low - not the lowest on record, but a sharp turn nonetheless - with mortalities heavily increasing. Remember this is the year of the Soda Butte incident, which caused quite a stir in the bear communities. A grand total of 28 incidents occurred that summer, making the 9 of the previous year look infinitesimal by comparison and most were very abnormal. Five of these are classified as "cause unknown, under investigation" while some others are incredibly disturbing. On October 19, a bear stalked a hunter from the elk he had just killed (apparently ignoring the carcass) and twice approached to a very close range, leaving the hunter no choice but to shoot it after the second pass. On October 23, a man was threatened by a bear. After attempting to drive it away with warning shots, he blasted it with pepper spray. The bear refused to be deterred and was killed when it went after the man a second time. On October 24, a similar scenario played out. A man tried to deter an approaching bear with gunshots and ultimately bear spray but both proved ineffective and he had to shoot it at close range. It's very telling that these three incidents occurred in October when the bears were attempting to fatten up for hibernation. The cones of the whitebark pine are their primary source of fat and very few were available to them. The loss of winter-kill carcasses thanks to the wolf reintroduction program no doubt plays a heavy part in their food shortage crisis as well.
2011 shows some improvement in the health and production of the whitebark pines but still not quite where the numbers need to be and a large number of abnormal bear incidents were still reported, totaling 27, with ten of those being "unknown, under investigation". In one case, a bear who killed a hiker presumably in a surprise encounter in July was later found present at the site of another death in August.
This data presents a very clear picture, yet so many scientists are still studying the whitebark pine situation - or just pretending to - and wildly speculating on the cause of the increased conflicts, while many bear advocates and enthusiasts have been left feeling as if they're standing on very shaky ground by these attacks. No doubt the rising bear population in Yellowstone is playing a big part, as there aren't enough food resources to go around. If this trend continues, the bears will spread outside of the park boundaries, if they haven't already, and the intolerance they're going to run into, and are already being met with, will not be pretty.
For more info and a look at the data gathered by the IGBST, go here: http://nrmsc.usgs.gov/research/igbst-home.htm
On their site, the IGBST maintains a list of bear mortality records in Yellowstone and whitebark pine health data from 2009 through 2011 and the correlation between the two is undeniable. 2009 shows one of the strongest whitebark pine production years on record and the bear mortality reflects that. In going through the records, I tried to eliminate attacks that could have been in defense of cubs or carcasses and focus only on those that were abnormal or in which bears raided campsites and residential areas in search of food. In all, 9 of these incidents were recorded, with one labeled as "cause unknown" and "under investigation". That's actually not as high of a number as it sounds and is probably fairly average, maybe just slightly above.
The change recorded in 2010 is very dramatic. Whitebark pine production is shown to be alarmingly low - not the lowest on record, but a sharp turn nonetheless - with mortalities heavily increasing. Remember this is the year of the Soda Butte incident, which caused quite a stir in the bear communities. A grand total of 28 incidents occurred that summer, making the 9 of the previous year look infinitesimal by comparison and most were very abnormal. Five of these are classified as "cause unknown, under investigation" while some others are incredibly disturbing. On October 19, a bear stalked a hunter from the elk he had just killed (apparently ignoring the carcass) and twice approached to a very close range, leaving the hunter no choice but to shoot it after the second pass. On October 23, a man was threatened by a bear. After attempting to drive it away with warning shots, he blasted it with pepper spray. The bear refused to be deterred and was killed when it went after the man a second time. On October 24, a similar scenario played out. A man tried to deter an approaching bear with gunshots and ultimately bear spray but both proved ineffective and he had to shoot it at close range. It's very telling that these three incidents occurred in October when the bears were attempting to fatten up for hibernation. The cones of the whitebark pine are their primary source of fat and very few were available to them. The loss of winter-kill carcasses thanks to the wolf reintroduction program no doubt plays a heavy part in their food shortage crisis as well.
2011 shows some improvement in the health and production of the whitebark pines but still not quite where the numbers need to be and a large number of abnormal bear incidents were still reported, totaling 27, with ten of those being "unknown, under investigation". In one case, a bear who killed a hiker presumably in a surprise encounter in July was later found present at the site of another death in August.
This data presents a very clear picture, yet so many scientists are still studying the whitebark pine situation - or just pretending to - and wildly speculating on the cause of the increased conflicts, while many bear advocates and enthusiasts have been left feeling as if they're standing on very shaky ground by these attacks. No doubt the rising bear population in Yellowstone is playing a big part, as there aren't enough food resources to go around. If this trend continues, the bears will spread outside of the park boundaries, if they haven't already, and the intolerance they're going to run into, and are already being met with, will not be pretty.
For more info and a look at the data gathered by the IGBST, go here: http://nrmsc.usgs.gov/research/igbst-home.htm
