With ravaged bird feeders, upside-down garbage cans and raided vegetable gardens, residents of St. Croix County have noticed an increased presence of black bears in the area.

Indeed, the state's black bear population has tripled over the last 20 years. According to the Wisconsin Department of Natural Resources, there were about 9,000 black bears in Wisconsin in 1989, and by 2008, the population had grown to between 26,000 and 40,000 bears.

In addition to population growth, area wildlife specialist Harvey Halvorsen attributed the bears' more pronounced presence to their increased urbanization. As the black bear population in northwestern Wisconsin becomes denser, cubs are forced to move out of their mother's territory to avoid being killed by larger boars. The cubs search for a more sparsely populated area, and the lower two-thirds of the state fit the bill.

Although the prevalence of bears has caused concern among some residents, Halvorsen said the animals do not pose a significant threat if people take the proper precautions. For example, as more bears move into urban areas and create homes near residents' backyards, people have taken to setting out food for them, which is Halvorsen's No. 1 no-no.

"When people give bears free handouts of food, it attracts them to urban areas and conditions them to humans," Halvorsen said. "Hunger also makes them more aggressive."

Indeed, bear encounters, or instances in which people see a bear, are becoming more common. Halvorsen said that if people encounter a bear, they should stay calm and not run away. Instead, look at the bear and slowly back out of the area.

"Let the bear know you're there," Halvorsen said. "In most cases, just talking to it will scare it away. If it gets on its hind legs, it's just trying to detect what you are and if you're dangerous."

Often, a black bear will bluff charge, popping its jaw and snapping its teeth with little intention of moving forward. However, if the bear advances, Halvorsen said people should yell, clap their hands or throw something at it.

Although they are not usually aggressive, black bears do have the potential to become violent if they are injured or nursing cubs. In the event that a black bear attacks, people should fight back and abandon the "play dead" method used with grizzly bears.

When the Bureau of Wildlife Management receives a level one call, which constitutes an imminent threat to human health and safety, it responds immediately by assessing the situation and determining whether the bear can be removed or whether it needs to be euthanized.

However, Halvorsen said these occurrences are rare. In the 18 years that he has served as the county's wildlife specialist, there has never been a bear attack.

"Animal populations that are wild and hunted are generally afraid of humans and avoid them at all costs," Halvorsen said. "It's true that the bear is more afraid of you than you are of it."

The majority of bear-related calls that the department receives are nuisance complaints, which are usually benign and dealt with via incident reports.

According to Halvorsen, the most common incident report is a level three: property damage. In this case, the department pinpoints the location of the bear for monitoring and gives the caller technical advice about safety.

Because black bears will eat almost anything, including garbage, bird seed and even livestock, the DNR suggests residents clean up outdoor grills, hang bird feeders at least 10 feet off the ground and bring pet food inside during the night.

Currently, Halvorsen is aware of two or three cubs creating a commotion in the Hudson area, and the strip of land near the Apple River complex in Somerset has also been home to some bears. The department estimates that two to four bears live in the county.

"Black bears live a long time and can stay in one area," Halvorsen said. "A male could have a 600-acre home range, and a female's could be anywhere from 200 to 400 acres."

In an effort to document the population, the department places bait -- usually peanut butter and oatmeal laced with tetracycline -- in several locations around the county. When a bear eats the bait, their teeth and part of their rib bone are stained, serving as an identifying mark. If the bear is killed during the legal hunting season, the department asks the hunter to provide a tooth and a portion of the rib bone.

Based on known markers of the population, the department can estimate how many bears are in the area and how many hunting permits it should issue for the following season. In 2006, 4,600 bears were killed in the state, and the population sat at around 40,000.

Despite the bears' increased prevalence in the county, Halvorsen said the majority coexist peacefully with humans, thanks to their desire to remain undetected.

"Ninety percent of the time, people don't know that they have a bear in their backyard," Halvorsen said. "They're now considered common in St. Croix County, and the black bear is really thriving in Wisconsin."

To report a black bear sighting, call the Department of Agriculture and Wildlife Services at (800) 228-1368. For more information, visit www.dnr.wi.gov.