Washington, Oct 1 : Black bears living in urban areas are more likely to die young than their wildland counterparts, according to a new study by Wildlife Conservation Society (WCS).
The researchers found that black bears that live around urban areas weigh more, get pregnant at a younger age, and are more likely to die violent deaths.
During the study, the research team tracked 12 urban bears over a 10-year period around Lake Tahoe, Nevada and compared them to 10 "wildland" bears that lived in outlying wild areas.
They found that bears in urbanized areas weighed an average of 30 percent more than bears in wild areas due to a diet heavily supplemented by garbage.
The authors believe that because the bears weigh more they are giving birth at an earlier age - on average when they are between 4-5 years old, as compared to 7-8 years for bears in wild areas.
Some urban bears even reproduced as early as 2-3 years of age around Lake Tahoe.
The urban bears tend to die much younger mostly due to collisions with vehicles.
During the study period, all 12 urban bears were dead by age 10 due to vehicle collisions, while six of the wildland bears still survived.
Bear cubs in urban areas also had dramatically higher mortality rates due mainly to vehicle collisions.
"Urban areas are becoming the ultimate bear traps," said Wildlife Conservation Society researcher Jon Beckmann, the study's lead author.
"Because of an abundant food source - namely garbage - bears are being drawn in from backcountry areas into urbanized landscapes where they meet their demise," he added.
The study warns that urbanized areas are functioning as "sinks" for black bear populations, drawing in bears from outlying wild areas, where they ultimately die.
As a result, bears are failing to re-colonize outlying wild areas following this shift to urban centres.