Polar bear–grizzly bear interactions during the autumn open-water period in Alaska

Polar bear-human interactions in Canadian national parks,1986-2000

Interactions between polar bears (Ursus maritimus) and humans in 6 national parks in the Canadian Arctic from 1986 to 2000 were examined (n = 53). No human fatalities and only 1 injury occurred. Bears were killed in only 4% of interactions, a much lower rate than in other studies, possibly because of the availability of deterrents. Interactions occurred mainly in summer in parks where bears are...

The Stream Cipher Polar Bear

We propose a new stream cipher called “Polar Bear”. It combines constructions used successfully in other situations. The key initialization uses Rijndael, the steady state uses a dynamic table as in RC4 and we guarantee a long period through the use of a linear feedback shiftregister. The efficiency for short messages is better than that of RC4 while for long messages Polar Bear is about a fact...

The Polar Bear — Ursus maritimus

Habitat Characteristics of Polar Bear Terrestrial Maternal Den Sites in Northern Alaska

Polar bears (Ursus maritimus) give birth to and nurture their young in dens of ice and snow. During 1999– 2001, we measured the structure of 22 dens on the coastal plain of northern Alaska after polar bear families had evacuated their dens in the spring. During the summers of 2001 and 2002, we revisited the sites of 42 maternal and autumn exploratory dens and recorded characteristics of the und...

Efficacy of Bear Deterrent Spray in Alaska

We present a comprehensive look at a sample of bear spray incidents that occurred in Alaska, USA, from 1985 to 2006. We analyzed 83 bear spray incidents involving brown bears (Ursus arctos; 61 cases, 74%), black bears (Ursus americanus; 20 cases, 24%), and polar bears (Ursus maritimus; 2 cases, 2%). Of the 72 cases where persons sprayed bears to defend themselves, 50 (69%) involved brown bears,...