Dave Anderson's Forest Journal
Evidence abounds that spring is bruins season
In May, headlines report an annual spike in New Hampshire wildlife sightings. Turtles wander seeking warm, sandy sites to lay leathery eggs. Hummingbirds arrive at local feeders. Pink lady slipper orchids are in bloom. Hordes of mosquitoes emerge.
And bears - LOTS of bears - suddenly are evident even in heavily developed regions of the state.
While there are ample supplies of natural foods in the forest, suburban neighborhoods offer attractive amenities to wandering bruins. In many instances of bears in close proximity to people, the motivation is birdseed - particularly black oil sunflower seeds.
When bears leave the woods, they cross roads and traverse neighborhoods where they rile barking dogs, climb backyard trees to reach birdfeeders, and ascend decks to reach garbage cans, pet food bowls and barbecue grills. Some people inadvertently attract bears to unnatural food supplies. Other people intentionally feed bears. And sows with first-year cubs teach their offspring bad habits to which adolescents return in subsequent years.
Conflicts between humans and bears and nuisance-bear complaints increase in suburban areas when homeowners inadvertently attract the animals. To better manage bears, wildlife officials annually educate people in an effort to prevent bears from habituating themselves to food and learning bad habits. The state Fish and Game Department's popular "Something's Bruin" campaign reminds homeowners, "A fed bear is a dead bear."
May begins the mating season for bears in New Hampshire. During their every-other-year breeding season, female "sows" enter estrus after leaving or driving off adolescent 2-year-old cubs. Twin cubs are typical. Bear cubs born in dens in January 2012 spent last summer with their mothers and shared a den this past winter. In this, the cubs' second spring, sows leave the adolescents to fend for themselves and prepare to breed again.
Breeding sows this year last mated in June 2011. Male "boars" breed every year - if they can.
Adolescents, particularly the males, now disperse to establish new territories while avoiding conflict with older, dominant males, who are busy defending territory and seeking mates. Young boars are interlopers in already-occupied territory, and they must travel warily to avoid conflicts. Dominant boars tolerate young sows that will mature to become part of a regional harem.
The home range for a dominant boar can be 50 square miles in good quality habitat to 100 square miles in poor habitat. Sows typically occupy a home range of 5 to 20 square miles. Thus, the home range of a boar may overlap ranges occupied by dozens of sows.
Adolescents and mothers with first-year cubs, breeding males and females all are actively traveling, feeding, mating, defending and maintaining territories while escaping threats posed by larger, dominant bears. This annual frenzy of bear movement results in an inevitable increase in reported sightings by late May.
Bears are particularly fond of hillsides and ridge locations. They frequent forests along saddles connecting hilltops. A decade ago, Forest Service biologists studying bear habitat preferences determined that bears preferentially feed in autumn in beech forests located on remote hillsides and along ridges. With an acute sense of smell and relatively limited eyesight, black bears rely on air currents to provide strategic, olfactory views of the surroundings.
If there's a readily available food source nearby - beechnuts, acorns, a cornfield, birdfeeders, a barbecue grill or dumpster - bears will smell it. When hikers with dogs approach from one side of a ridge, bears flee down the opposite side before the threat is near enough to see or hear. Mountainous topography provides a strategic advantage because bears constantly sniff air currents, conveying up-to-the-minute news headlines. The topographic "scent-scape" influences bear-travel corridors and preferred feeding and resting locations.
The travel corridors connecting large blocks of farms and forestland are important in regions fragmented by roads and residential development. Crowds of people in more urban areas frighten bears up neighborhood trees or even utility poles. Typically, bears climb down and return to the forest after people leave.
Binoculars are the safest and most responsible way to enjoy New Hampshire bears. If you are fortunate enough to see a bear in your neighborhood, give it space. Fish and Game authorities annually remind residents that wild animals have the best chance of surviving when they are left alone in their natural habitat.
"Forest Journal" appears every other week in the New Hampshire Sunday News. Email naturalist Dave Anderson is director of Education and Volunteer Services for the Society for the Protection of New Hampshire Forests, at email@example.com or through the website forestsociety.org.