Black bears captivate the experts
BY DONNA ROLANDO
Beyond the emotion-pitched storm that kicks up annually over whether to hunt black bears – beyond the complaints that they broke into a home or pillaged trash – is an animal that thrives in New Jersey's forests yet remains a mystery to most people.
What probably gets the bear into the most trouble, drawing him into residential areas and campgrounds, is his nose.Bears have been documented, according to DFW in "Black Bear Biology and Behavior," detecting scents more than two miles away from a food source with the help of a nasal mucous membrane 100 times larger than that in a human.This means forget about hiding your trash; it's best to secure it. Human trash can be easy pickings for this opportunistic feeder, but the black bear is fully equipped to find food in its natural habitat of mixed hardwood forests, dense swamps, and forested wetlands. Although near-sighted, the bear can see colors, great for finding berries and fruits. And they get night vision from a reflective layer in the back of their eyeball, which mirrors the moonlight.
Although trash can lure a bear away from his typical diet of 75 percent plants, Carr said that based on the state's tagging program, which includes radio and GPS collars, "We know they are not spending much time in the community. They are using the forest and the wetlands around these communities."
Also amazing, she said, is their long period of "hibernation," which for the impregnated female begins the last week in October, while males may not enter the den until December."Just the idea they can be in a state of hibernation all that time without eating, without defecating or whatever…," she said. The small amount of urine that is produced is reabsorbed by their kidneys, according to "Black Bear Biology and Behavior." Bears live off their body fat, losing between 18 percent and 20 percent of their body fat while in their dens but retaining their bone and muscle mass. During their winter dormancy, their heart and respiratory rates slow and their body temp drops, but not to the extent of true hibernators like the woodchuck.
As a chief advocate for the environment, Tittel also marvels that the black bear is making a comeback in the most densely populated state – a sign of the state achieving a more fully developed ecosystem to sustain them. Forty years ago, he said, black bears in New Jersey numbered only 50. Now, according to the 2010 Comprehensive Black Bear Management Policy, the population estimate is 3,400 bears for the portion of New Jersey north of Interstate 80.
Another aspect that readers might find unusual about black bears is how biology puts mother bears (ranging in age from 2 to 20) on a mission in contrast to human behavior: to gain lots of weight and in particular build a large fat reserve before she dens in the fall. Her fertilized egg will remain "in limbo," as Garbowski puts it, free-floating in the bear's uterus, unless she can break the scale. "Delayed implantation" means that the fertilized egg will only implant in the uterine in November if she has consumed enough to carry the cubs to term and provide milk for them throughout the winter. Bears need to consume a minimum of 20,000 calories a day to prepare for the winter den season, which means plenty of berries in summer and mostly acorns and nuts in the fall. "In the fall they gain 2 pounds a day," Carr said.
Carr describes black bears as "long lived," surviving 25 to 28 years in the wild. If they survive the first four years, their odds of survival rise to 90 percent. During the first year, the odds are 70 percent partly because they can become the target of older male bears. Outside of hunting, Carr said that motor vehicle strikes take the most adult bears, claiming 75 lives a year. Other causes of death might be lethal action against an "aggressive" bear, electrocution after climbing a utility pole, or disease. Carr noted some cases of mange in Pennsylvania as well as evidence that New Jersey bears have antibodies for West Nile Virus and therefore can be affected by that disease as well. As they get older, too, their teeth wear out, said Carr, citing another tax on the animal's health. When a bear dies in the wild from any of these causes, he said, its body will decompose, going back to the nature that sustained it through its life.
What have wildlife experts come to know and appreciate about New Jersey's largest land mammal? For state wildlife biologist Patrick Carr, the answer is the bear's ability to live secretly on the fringes of residential neighborhoods staying out of sight…most of the time.If you've hiked northern New Jersey woodlands and never seen a black bear (Ursus americanus), you probably haven't looked very closely, said Carr, a supervising biologist for NJ Division of Fish & Wildlife (DFW). "You don't see the vast majority of them," he sd. "You walk by a lot more bears than you think aiand they don't bother you.
"They're very good at living among us. They avoid humans when they can and use available cover to live by humans." Managing this at a maximum weight potential of 600 pounds makes it all the more amazing, he said. Within the most densely populated state in the nation, black bears are thriving and have been confirmed by sightings in all 21 counties, according to the division's website. Yet if people were more attuned to the stealth maneuvers of the black bear, he predicts, the number of sightings would almost double.
What probably gets the bear into the most trouble, drawing him into residential areas and campgrounds, is his nose.Bears have been documented, according to DFW in "Black Bear Biology and Behavior," detecting scents more than two miles away from a food source with the help of a nasal mucous membrane 100 times larger than that in a human.This means forget about hiding your trash; it's best to secure it. Human trash can be easy pickings for this opportunistic feeder, but the black bear is fully equipped to find food in its natural habitat of mixed hardwood forests, dense swamps, and forested wetlands. Although near-sighted, the bear can see colors, great for finding berries and fruits. And they get night vision from a reflective layer in the back of their eyeball, which mirrors the moonlight.
Although trash can lure a bear away from his typical diet of 75 percent plants, Carr said that based on the state's tagging program, which includes radio and GPS collars, "We know they are not spending much time in the community. They are using the forest and the wetlands around these communities."
Small beginnings
For Dee Garbowski, founder of Wanaque-based Wildlife Freedom, the marvel is how black bears come into the world in January smaller than a human baby at 8 to 16 ounces."This gigantic big bear gives birth to a bear that's only 8 ounces," she said. "Eight ounces, to me, that's phenomenal." It's rare for humans to get a glimpse of the newborns since the mother does not emerge from the den with her cubs – an average of three per litter – until April when they weigh at least 5 pounds.But Garbowski said there was a chance to see the new arrivals prior to the demolition of an old stone house in West Milford, where a sow had made her den."The babies look like giant spiders on their mother," she said.Also amazing, she said, is their long period of "hibernation," which for the impregnated female begins the last week in October, while males may not enter the den until December."Just the idea they can be in a state of hibernation all that time without eating, without defecating or whatever…," she said. The small amount of urine that is produced is reabsorbed by their kidneys, according to "Black Bear Biology and Behavior." Bears live off their body fat, losing between 18 percent and 20 percent of their body fat while in their dens but retaining their bone and muscle mass. During their winter dormancy, their heart and respiratory rates slow and their body temp drops, but not to the extent of true hibernators like the woodchuck.
Alone in the world
For Jeff Tittel, executive director of the New Jersey Sierra Club, one of the marvels has been the social network of bears and how they raise their young. As a Ringwood resident, he's had occasion to see a bewildered adolescent bear on the day he was probably chased off by his mother, having reached the age of 16 to 18 months. "He looked so scared and so frightened that he was now on his own," Tittel said. By sending yearlings off to fend for themselves and set up their own home range, the mother is free to breed again; she has already taught each yearling how to get food and stay out of danger.As a chief advocate for the environment, Tittel also marvels that the black bear is making a comeback in the most densely populated state – a sign of the state achieving a more fully developed ecosystem to sustain them. Forty years ago, he said, black bears in New Jersey numbered only 50. Now, according to the 2010 Comprehensive Black Bear Management Policy, the population estimate is 3,400 bears for the portion of New Jersey north of Interstate 80.
Another aspect that readers might find unusual about black bears is how biology puts mother bears (ranging in age from 2 to 20) on a mission in contrast to human behavior: to gain lots of weight and in particular build a large fat reserve before she dens in the fall. Her fertilized egg will remain "in limbo," as Garbowski puts it, free-floating in the bear's uterus, unless she can break the scale. "Delayed implantation" means that the fertilized egg will only implant in the uterine in November if she has consumed enough to carry the cubs to term and provide milk for them throughout the winter. Bears need to consume a minimum of 20,000 calories a day to prepare for the winter den season, which means plenty of berries in summer and mostly acorns and nuts in the fall. "In the fall they gain 2 pounds a day," Carr said.
Keeping tabs
Technology – those radio and GPS collars mentioned above – has enabled the state to track the movements of its black bears, but it has also opened the door to further questions – like why a mother bear a few days after hunting season in New Jersey would head west to the Delaware River and winter in Pike County, Penn. She returned with her cubs just recently, heading back over the Delaware into Montague. With the help of Global Positioning Systems in eight collars, satellite signals help the state monitor the bears' travels daily. Thirty bears have radio collars, which also fill the state in on the bears' use of habitat. To further monitor bears, Carr said, "We tag and release alive over 300 black bears a year." Since 1981 DFW personnel have handled over 3,600 individual black bears, tagging and releasing alive over 2,400 bears, according to the state's black bear management plan.Carr describes black bears as "long lived," surviving 25 to 28 years in the wild. If they survive the first four years, their odds of survival rise to 90 percent. During the first year, the odds are 70 percent partly because they can become the target of older male bears. Outside of hunting, Carr said that motor vehicle strikes take the most adult bears, claiming 75 lives a year. Other causes of death might be lethal action against an "aggressive" bear, electrocution after climbing a utility pole, or disease. Carr noted some cases of mange in Pennsylvania as well as evidence that New Jersey bears have antibodies for West Nile Virus and therefore can be affected by that disease as well. As they get older, too, their teeth wear out, said Carr, citing another tax on the animal's health. When a bear dies in the wild from any of these causes, he said, its body will decompose, going back to the nature that sustained it through its life.
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