Bear-resistant garbage cans changed where bears scavenged for food in Durango over four years.
Colorado Parks and Wildlife gave out 1,100 bear-resistant cans in 2013 to households in two areas of town to test how well they would deter bears. Two other areas that did not receive the cans were also monitored, Heather Johnson told the Durango City Council.
As a result, Johnson and her team saw a clear shift in bear trash raids and other problems to those neighborhoods without bear-resistant cans.
The report this week was timely, as BearSmart got its first bear sighting report of the season in Durango.
The six-year study found that conflicts between bears and humans are likely to continue, and as bears continue to forage in urban areas, it could lead to bear population declines.
The team gathered data by collaring female bears to track their movements, monitoring garbage cans in town for disturbances and setting up hair snares to estimate population. The study covered 800 square kilometers in and around Durango.
Bear-resistant cans are better at curbing human-bear conflicts than reducing the number of bears or relocating them, she said. “The only thing that has continually worked is locking away human food,” she said.
The city planned to spend $600,000 to buy bear-resistant cans over the next three years, Director of City Operations Levi Lloyd told council. But the decision to buy cans and how to distribute them is up to future councils, City Manager Ron LeBlanc said. The city plans to use the study’s maps, which show hot spots for bear activity, to determine how to best distribute cans. Residents would pay back the cost of the cans over time as part of their trash bill.
Not all neighborhoods need the bear-resistant cans because some residents are required by covenants to keep their trash locked in the garage, he said.
Neighborhoods where trash cans are kept in alleys have a higher rate of conflict, Johnson said.
The study also showed it doesn’t take 100 percent of people keeping the cans locked to make a difference, she said. Neighborhoods with 60 percent compliance had fewer bear problems.
Plentiful food in the forest also helped keep bears out of town. But in 2012, when a hard freeze in June bit the berries and nuts in the forest, the bear population fell dramatically, in part because bears came to town and were hit by vehicles or euthanized because of aggressive behavior.
Normally, bears will survive tough years and they won’t reproduce.
The study estimated that the female bear population in the study area fell from about 200 in 2012 to about 82 bears in 2013. Johnson predicts increased conflicts based on how bears are using human sources of food.
Over the last six years, her study documented 15 reports of aggressive bears; 200 home, vehicle or garage break-ins; 100 attempted break-ins; and 3,000 calls about bears getting into trash in the study area.
Bears perceive risk associated with towns, but will seek out human food if the reward outweighs the risk, Johnson said. Also, bears spend less time hibernating, and that trend is likely to continue because human food is available year-round and temperatures are rising, she said.
“We are going to see bears active a lot more of the year,” she said.
Reports to BearSmart, a local nonprofit, have noticed a similar trend. The organization’s first bear report of the season came in Wednesday, when a bear was spotted on Goeglein Gulch Road, Executive Director Bryan Peterson said.
Cities must commit to using bear-resistant trash cans to keep bears away, said Charles Anderson, mammals research leader for Colorado Parks and Wildlife.
“It comes down to municipalities though, they are really the ones that have to enforce it,” he said.