It's not news that black bears across North America are being lured to urbanized areas by a cornucopia of garbage. As a result they are fatter and thus give birth to cubs much earlier than their cousins in outlying wild areas, according to a study by the Wildlife Conservation Society. But they are also likely to die a violent death at a young age--usually in collisions with vehicles.
Dumpster-diving urban bear (Colorado Division of Wildlife)
Over a 10-year period, biologists Jon Beckman from WCS and Carl Lackey from the Nevada Department of Wildlife tracked 12 bears living in urban areas around Lake Tahoe and 10 in surrounding wildlands. They found that urban bears were an average of 30 percent heavier due to their garbage diet and gave birth as early as 2-3 years of age compared to 7-8 years for wild-roaming animals. All of the urban bears being tracked by the researchers were killed by vehicles by the age of 10, along with most of their cubs, but six bears from the wildlands group still survived.
"Urban areas are becoming the ultimate bear traps," said Beckman. "Because of an abundant food source, they are being drawn in from backcountry areas into urbanized landscapes where they meet their demise." This shift and the heavy mortality, he noted, could be having an adverse impact on Nevada's black bear population.