Black bears lose half their body weight during hibernation. When they come out of the den, they’re hungry, irritable and not very picky about where they get their calories.

At this time of year, these eating machines tend to look for the easiest and closest source of high-protein food. Think bird feeders (almost 2,000 calories per pound); and pet food and garbage, even at your campsite.

“When bears have learned to associate food sources with people, situations often end badly for the bear,” said Rich Beausoleil, bear specialist for the Washington Department of Fish and Wildlife. In some cases, a bear may be tranquilized and moved, or even shot by wildlife officers.

There are an estimated 25,000-30,000 Ursus americanus in the state. They weight 100-300 pounds and stand 2½-3 feet at the shoulder. They are faster than you.

Their sense of smell may be the best among mammals and perhaps the animal kingdom. How strong that sense is depends on the source of information. For instance, they may detect animal carcasses upwind and from a distance of 1-20 miles away; black bears have been observed to travel 3-18 miles in a straight line to a food source. (Who observes a bear traveling 18 miles in a straight line?)

State laws prohibit leaving food or food waste in places where it can attract bears. For those scofflaws feeding bears, intentionally or unintentionally, there’s an $87 fine, while the fine for intentional feeding can be as much as $1,000.

Consider these tips for a safe camping experience:

Keep a clean camp, cook 100 yards from camp, and thoroughly clean all spilled food and cooking utensils; wash your hands and face (and your children’s, too).

Keep children close on the trail. An unleashed dog might chase after an unseen bear, and realizing that it is in trouble, may dash back to camp, bear following.

When camping overnight, particularly in the backcountry, seal uneaten food in airtight containers that are stored in bear-proof canisters at least 100 yards away from camping areas. Avoid storing food in your car.

Common sense doesn’t get in the way of having fun.

Open, but. The North Cascades Highway is open, but be prepared for contractors putting down rumble strips into the asphalt along nearly 42 miles of the road. No work is done on weekends.

Riding the trails. A national celebration Wednesday of the Great American Rail-Trail Conservancy honors a nearly 4,000-mile multi-use stretch that includes the 212-mile Palouse to Cascades State Park Trail. The Palouse section stretches to Cedar Falls, east of Seattle. The event will start at 10:30 a.m. May 8 in the South Cle Elum Rail Yard National Historic District, 801 Milwaukee Ave.

Transit to trails. The Trailhead Direct program, operating weekends and holidays, mostly in Seattle and King County, offers service to more trailheads than last year. The program makes the trails more accessible, as well as keeping cars out of busy trailheads. Vehicles seat 12-17 hikers, and each van has a rack for either two or three bikes. Passengers pay Metro’s standard $2.75 fare. For information on schedules and service routes, visit www.trailheaddirect.org.

Sick bats. White-nose syndrome, a fungal disease that affects hibernating bats, has been confirmed for the first time in a western long-eared bat in King County. This brings the number of bat species confirmed with the deadly fungal disease in North America to 12. First seen in North America in 2006 in eastern New York, white-nose syndrome has killed millions of hibernating bats in eastern North America and has now spread to 33 states and seven Canadian provinces.

A natural prescription. The Park Rx program has been launched by Washington State Parks, working with health-care providers to prescribe nature to their patients. “Doctors and other health professionals are realizing the healing power of being outdoors and have taken to prescribing parks and other natural areas to their patients using www.parkrxamerica.org to address diabetes, obesity, hypertension, depression and anxiety,” said Dr. Robert Zarr, founder and pediatrician.

Sharon Wootton can be reached at songandword@rockisland.com or 360-468-3964.