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Environmental News

Durango Bears Provide Research for State

A bear lays temporarily immobilized in order to
process information regarding the
numerous bear-sightings in town.
Photo courtesy of Heather Johnson Principal Investigator

Story by Jimi Giles

Black bear-human conflicts have been evident this summer and fall in Durango’s town area, but the addition of repetitive bear sightings on Fort Lewis College caused an official FLC announcement to be sent via email on Sept. 19. 

The email informed recipients that the FLC Police Department have received reports of bear sightings on the Front Hill and the Chapel and informed recipients of proper behaviors if bear encounters occur.       

Colorado Parks and Wildlife implemented a black bear research study in Durango because of the town’s consistently high rates of bear-human conflicts, principal investigator of the project Heather Johnson said.

Bear-human conflicts appear to be increasing in Colorado, particularly around urban environments, and the CPW wants to better understand how to manage and reduce these conflicts and learn about factors that exacerbate them, she said.

 “We know very little about bears in terms of their population size, their trajectories in terms of whether their populations are increasing or decreasing in size,” Johnson said. 

The study, referred to as the Durango Bear Research Project, is projected to last five to six years and is gearing for its second winter session, Johnson said. 

The study has four goals, the first of which involves testing different management strategies to reduce bear-human conflicts, she said. 

A bear-human conflict is one where a bear damages property or poses a threat to public safety, she said.

“The second one is we want to better understand what the influence of urban environments is on bear populations, both in terms of their behavior and population dynamics, because a state like Colorado has human development throughout,” Johnson said.

The third goal is to better understand human attitudes and perceptions of bears, bear-human interactions, and bear management, and the fourth goal is to develop better population and habitat models to support bear management, she said.

A major component of their second goal involves trapping and collaring adult female black bears, which is done during the project’s summer sessions, Johnson said. 

Females are collared because they provide more information about population dynamics as they are the reproductive segment of the population.  An adult bear is considered able to reproduce, typically between ages four and five, she said.

Once a bear is trapped, blood and hair samples are collected.  If the bear is an adult female, a tooth is pulled for age verification and the sow is fitted with a collar, Johnson said.    

Blood and hair samples allow for DNA extraction and the premolar tooth sample, roughly a half-inch long with root, allows age analysis, she said. 

The tooth extraction doesn’t detrimentally affect the bear, and age analysis is done in a separate laboratory where views of its cross-sections allow technicians to determine the bear’s age, Johnson said.

Collars placed on an adult female transmit a signal of the bear’s location every six hours.  The collars’ batteries last two years, and the collars are estimated to work for four years.  Each collar costs up to $4,000, Johnson said.

By tracking a bear’s location, researchers are able to see how bears use the urban environments, and how that use influences their survival and reproduction, she said.

So far, Johnson and her team have collared a total of 51 bears but have had several mortalities this summer due to harvest and vehicle collisions, she said.  Their goal is to have a sample of 40 bears collared per year.  Currently, there are 37, she said.

Bears evolved to hibernate as a means to deal with a lack of food availability in the winter, Johnson said.  Hibernation usually begins in the month of November and lasts until around the first of April, she said.

Right now, in preparation for hibernation, bears are in a state of hyperphagia, or overeating.  In this state, bears can eat up to 20 hours a day, Fort Lewis College professor of wildlife management Erin Lehmer said.

Energy wise, bears can eat up to 20,000 calories a day leading to hibernation, Johnson said.

“Within a month they can increase their body mass by 30 or 40 percent,” Lehmer said.

Bears have a large home range: for females, it is 10 to 15 square miles, and for males, it is double, Johnson said.  Because bears can smell food up to five to 10 miles away and digest foods that humans consume, bears can perceive town as a food source, she said.

The normal fall food staples for bears include acorns, serviceberries, and chokecherries, Johnson said.

Johnson and her research team have been surveying the study area looking at the acorn and berry production after this dry season. 

“In most places, it’s just flat-out failure,” she said.

The low amount of natural foods for bears this year is a strong factor in why there have been a higher number of conflicts between bears and people and why people have been seeing and experiencing them this summer and fall more than usual, she said.

“This year, in particular, we’ve had more conflicts and more bear mortalities around Durango than is typical,” Johnson said.

Bear mortalities are generally attributed to harvest, vehicle collisions, or conflict removals.  If bears spend more time in town, vehicle collisions and conflict mortalities have the potential to increase, she said.

“Most of the bear encounters are just a nuisance,” Lehmer said.

Many Durangoans have experienced their trash being scattered by wildlife, and some may not realize that it violates a city ordinance.

“The way our ordinance is written, any wildlife scattering trash is considered a violation,” Durango Police Code Enforcement Officer Steve Barkley said. 

Most of the blame is directed towards bears, which are primary culprits, but blame is also given to raccoons and dogs, Barkley said.

If the ordinance is violated for the first time, trash owners are given a courtesy warning about obtaining a wildlife-proof container, he said.

After a warning has been given and whether or not the violator has changed containers, a $50 fine is given.  If trash continues to be tampered with, the fine raises to $100 and then again to $200.  After $200 fine, violators are scheduled for a hearing with the Municipal Court, where a maximum penalty for a city ordinance violation is a $1,000 fine or up to 90 days in jail, Barkley said.

About 90 percent of the citations given have been warnings, he said.

“Five fines have issued so far this year, and I suspect that to increase pretty rapidly because most people are converting to wildlife cans but they are forgetting to lock them,” he said.

Hot spots for trash tampering via wildlife in town are from East Fifth Avenue towards Skyridge, from Third Street to 15th Street, and from North 30th Street to 37th Street, Barkley said.

By bringing in bird feeders or putting out trash cans the day of pick-up, citizens can avoid inducing unwarranted bear behaviors, Lehmer said.

In a state like Colorado, there are not many places that bears can live without interacting with human development, Johnson said.

In a city like Durango, bears will always be present as the area is high quality bear habitat with an abundance of oak brush and berry-producing plants, she said.

FLC to Have the First Composter of its Type in Durango: Composter can break down 97% of waste into usable soil

Photo by Allie Johnson

Story by Mitch Fraser

The arrival of Fort Lewis College’s new composter means reduced waste and an eco-friendly image for the campus.

Read the rest of entry ยป

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