دانلود رایگان مقاله انگلیسی حمله خرس قطبی به انسان: پیامد های تغییرات آب و هوایی - وایلی 2017

ABSTRACT

Understanding causes of polar bear (Ursus maritimus) attacks on humans is critical to ensuring both human safety and polar bear conservation. Although considerable attention has been focused on understanding black (U. americanus) and grizzly (U. arctos) bear conflicts with humans, there have been few attempts to systematically collect, analyze, and interpret available information on human-polar bear conflicts across their range. To help fill this knowledge gap, a database was developed (Polar Bear-Human Information Management System [PBHIMS]) to facilitate the range-wide collection and analysis of humanpolar bear conflict data. We populated the PBHIMS with data collected throughout the polar bear range, analyzed polar bear attacks on people, and found that reported attacks have been extremely rare. From 1870–2014, we documented 73 attacks by wild polar bears, distributed among the 5 polar bear Range States (Canada, Greenland, Norway, Russia, and United States), which resulted in 20 human fatalities and 63 human injuries. We found that nutritionally stressed adult male polar bears were the most likely to pose threats to human safety. Attacks by adult females were rare, and most were attributed to defense of cubs. We judged that bears acted as a predator in most attacks, and that nearly all attacks involved
2 people. Increased concern for both human and bear safety is warranted in light of predictions of increased numbers of nutritionally stressed bears spending longer amounts of time on land near people because of the loss of their sea ice habitat. Improved conflict investigation is needed to collect accurate and relevant data and communicate accurate bear safety messages and mitigation strategies to the public. With better information, people can take proactive measures in polar bear habitat to ensure their safety and prevent conflicts with polar bears. This work represents an important first step towards improving our understanding of factors influencing human-polar bear conflicts. Continued collection and analysis of range-wide data on interactions and conflicts will help increase human safety and ensure the conservation of polar bears for future generations.

DISCUSSION

This research offers the first comprehensive assessment of polar bear attacks on people, the frequency of which has historically been low. For example, between 1960 and 1998, black and grizzly bears caused 42 serious or fatal human injuries in Alberta, Canada (Herrero and Higgins 2003). Herrero et al. (2011) documented 63 fatal attacks by black bears from 1900 to 2009 throughout North America. Conversely, over the 145-year period we investigated, we found records of only 73 confirmed polar bear attacks that resulted in 20 human fatalities and 63 human injuries. We acknowledge that we likely have not discovered or had access to information on all the attacks that occurred during the period investigated, and some attacks occurred that were likely never recorded. Regardless, under historical sea ice conditions and human population levels in the Arctic, the odds of being killed or injured by a polar bear were low.

Although the risk of a polar bear attacking a person remains low, it does exist, particularly when bears are nutritionally stressed and in poor body condition, which was characteristic of bears involved in the majority of attacks we analyzed. It is reasonable to postulate that polar bears (which are obligate carnivores) in poor body condition represent a greater threat to people than polar bears in above-average body condition. Indeed, those living near polar bears commonly report that bears in poor nutritional body condition are much more dangerous and aggressive than bears in good condition (Voorhees et al. 2014). This is supported by data presented here, which indicates that the body condition of polar bears is a significant factor contributing to their attacking people.