Living with Bears in the Northern Virginia Piedmont
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This presentation was given by Marshall Jones of the Smithsonian Conservation Biology Institute with slides from the Virginia Department of Game and Inland Fisheries. It was given at the Piedmont Environmental Council's Thumb Run Habitat Project Open House in Orlean, Fauquier County, VA on November 13, 2013. For more information about the project, visit www.pecva.org/habitat
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Living with Bears in the Northern Virginia Piedmont
- 1. Living with Bears in the Northern Virginia Piedmont Virginia Department of Game & Inland Fisheries Additions by Marshall Jones Smithsonian Conservation Biology Institute
- 2. What Species of Bear Lives In Virginia? Only Black Bears!
- 3. What Kind of Bears Are In Virginia? No Brown (=Grizzly) Bears!
- 4. How Big are Black Bears? Weight Males (boars) adult weight 200-500 pounds Females (sows) adult weight 100-250 pounds
- 5. General Features Large, non-retractable claws Used for: Digging up insects Defense Especially for climbing trees!!
- 6. Why Do Bears Stand Up? Nearsighted Upright posture improves their view Keen senses of smell & hearing
- 7. GeneralHistory Life Features Males in VA ï¶ home range : 10300 square miles Females in VA ï¶ home range : 1-50 square miles Varies widely by season, habitat quality, and reproductive status Maleâs home range will usually overlap several female home ranges
- 8. What Bears Eat ïź ~75% vegetative matter; berries, nuts, grasses, and fruits ïź ~25% insects, worms, larvae, carrion, small animals, and fish. Although not particularly good hunters, they have been known to prey on small to medium-sized mammals such as rodents and deer fawns.
- 9. . What do Ants and Hot Tubs have in common?
- 10. . What do ants & hot tubs have in common? Formic acid Formic acid is probably a reason bears sometimes bite into insulated snowmobile seats, hot tub covers, and refrigerator walls. These items all produce formic acid when the formaldehyde in the insulation breaks down, making them smell like ant colonies.
- 11. The Importance of Fall Foods ïź Bears may gain as much as 1-2 pounds per day beginning in late summer through the fall in preparation for denning ïź Need high energy foods to gain weight ïź Most important = Acorns, hickory nuts, beechnuts, hazelnuts ïź Cultivated corn, peaches, cherries, apples, and other fruits attract bears especially when natural food sources are scarce
- 12. Winter âHibernationâ Enter dens: Oct.-Jan. Time of entry depends on reproductive status, weather, and available foods Den sites in Virginia Rock cavities, excavations, brush piles, trees, snags In western Virginia, they use a high percentage of tree dens (~69%). In eastern Virginia, they more often found in ground dens. Tree den Ground dens
- 13. Winter âHibernationâ Not True Hibernators : body temperature comes within ~2 °F of surrounding temperature Bear body temperature only falls 9-14°F Do not eat, drink, urinate or defecate Respiration/heart rates decrease May lose 30% body weight Easily aroused from slumber
- 14. Reproduction âŠ ïź ïź ïź Cubs born mid-late January in den (Âœ to Ÿ lbs) Litter size ~2.5, range 1-4 1 day old cub Born blind and helpless 5 day old cub
- 15. Reproduction âŠ ïź 20-25% cub mortality rate during the first year ïź Rely on their mother through the next denning season
- 16. Bears on the Move SPRING ïź ïź ïź ïź Bears leave dens in search of food - Food is limited Female bears : Travel with cubs Male bears: Mostly solitary Yearlings may be with siblings
- 17. Bears on the Move SUMMER ïź Yearlings left to fend for themselves â Females may establish home ranges near mother â Males may travel far to find unoccupied range ïź Mating â Adult males may increase home range searching for mates
- 18. Distribution and Abundance ïź ïź ïź Pre 20th Century - limited info. Early 1600âs, Colonial times - abundant statewide 1739 bears only in western mountains and swamps â human population growth ïź By 1900 - near extinction in VA â typical agriculture; extensive deforestation, burning, grazing, cultivation = little habitat left for bears
- 19. Distribution and Abundance ïź 1911 land purchases began â Mt Rogers, Natural Bridge, Shenandoah National Park ïź Ag-land began reverting back to forests ïź Creation of parks secured protected habitat for bears
- 20. 1950âs Occupied Black Bear Range
- 21. 1980âs Occupied Black Bear Range
- 22. 1990âs Occupied Black Bear Range
- 23. 2000âs Occupied Black Bear Range
- 24. Bear Population Dynamics ïź Populations grow very slowly â Maximum 25% increase per year, not in hunted areas ïź Slow recovery from low populations ïź Hunting mortality is additive â Bears killed by hunters are in addition to those who would have died from natural causes
- 25. Afraid to Go Outside? In this part of the black bear range: âą Black bears do not exhibit predatory behavior âą In Virginia there has never been an unprovoked attack on a person since Jamestown was
- 26. Human Deaths Related to: Black Bears 1 Every 2 years in ALL OF NORTH AMERICA 15 Year 1000 Day Hurricanes 16 Year Tornadoes 65 Year Being Struck by Lightning 70 Year Bee Stings 80 Year Riding a Bicycle 800 Year Accidental Gunfire 1500 Year Walking / Pedestrians 8000 Year Murder/Homicides 17,000 Year Automobile Accidents 47,000 Year 150 Year 885,000 Year IN THE UNITED STATES ONLY: Dog Attacks Non fatal visits to emergency room from dog bites Automobile Collisions with Deer Cardiovascular Disease
- 27. Bears in your backyard?
- 29. Never Feed Bears! In VA, it is illegal to deliberately feed bears on public or private lands. Even the inadvertent feeding of bears is illegal.
- 30. Remove or Secure All Potential Sources of Food Bird feeders Garbage Pet food Vegetable crops and fruits Bee hives Livestock food
- 31. Bear Proof !
- 32. Take Down Birdfeeders April 1 st â December 1 st 30% of Bear Complaints are Birdfeeder Related
- 34. Acorns vs Cheeseburger Living with Wildlife Foundation A dozen eggs = 888 calories = 234 acorns. A pound of hot dogs = 1,456 calories = 384 acorns. A McDonaldâs double cheeseburger combo = 1,620 calories = 427 acorns. A pound of Black oil sunflower seeds = 1,740 calories = 458 acorns. A dozen Jelly donuts = 2,640 calories = 695 acorns. A large Pepperoni Pizza = 17,352 calories = 4,566 acorns.
- 35. Feed your pets, not bears! Feed pets only what they will eat. Remove bowl soon after they finish. Do not leave food out overnight. Store pet food in secure location.
- 36. Don ât forget the grill! Keep outdoor grills clean Do not leave food scraps or spilled grease in your yard
- 37. Protect Crops and Orchards ïź Set up electric fencing ïź Use ïź Pick noise makers ripe fruit and remove fallen fruit
- 39. Electric Fences
- 40. Bear Proof Home and Neighborhood ïź Talk to your neighbors â It only takes oneâŠ. ïź ïź ïź ïź ïź ïź ïź Screen-porches should not be used for storage Remove fruit producing plants from around your home Keep garages closed at night Secure outbuildings Bear âUnwelcomeâ mats Paintball guns Talk with your community leaders about bear proof trash disposal and pickup options
- 41. A Bear in Your House ïź ïź DONâT PANIC Open all doors to outside â Keep something handy near doors ïź Get out of the way â Donât block escape routes ïź ïź Yell, throw things, make noise Donât approach but donât back down
- 42. Nuisance Bear Management Why Translocation May Not Be an Option âą A bear can travel hundreds of miles and can return to a known food source within days. âą Bears returning to original sites are often hit by cars. âą When relocated, a nuisance bear could become someone else's problem. âąTranslocation does not solve the original problem of food attractants.
- 43. Nuisance Bear Management Future of Nuisance Bear Management âą Prevention! Prevention! Prevention! âą Home and landowner awareness âą Community involvement âą Deterrents / Aversive conditioning
- 47. Bear Population Objectives Map (generally ensuring that similar zones have similar objectives )
- 48. More Information Black Bear Management Plan http://www.dgif.virginia.gov/wildlife/bear/ Be Bear Aware and Wildlife Stewardship Campaign www.BeBearAware.org Living with Bears: A Practical Guide to Bear Country Linda Masterson, 2006 North American Bear Center www.bear.org
- 49. More Information Rappahannock League for Environmental Protection www.rlep.org Smithsonian Conservation Biology Institute Marshall Jones jonesmp@si.edu, 540-635-6517
Hinweis der Redaktion
- Here are some of the basics on black bear biology and life history information: We generally call male bears âboarsâ and refer to female bears as âsowsâ Adult males can weigh between 200 and 500 pounds and adult females are generally lighter and rarely will exceed 250 pounds.
- (*) Bears have large, non-retractable claws that they use for digging insects, climbing trees, and defense. (*)
- Is it true that a bear's sense of smell is 7 times greater than that of a bloodhound?Indeed it is. There is perhaps no other animal with a keener sense of smell. Bears rely on their sense of smell to locate mates, detect and avoid danger in the form of other bears and humans, identify cubs, and FIND FOOD. Although the region of the brain devoted to the sense of smell is average in size, the area of nasal mucous membrane in a bear's head is one hundred times larger than in a human's. This gives a bear a sense of smell that is 7 times greater than a bloodhound's. In addition, they have an organ called a Jacobson's organ, in the roof of the mouth, that further enhances their sense of smell. A bear has good eyesight at short range, but rather poor eyesight at longer distances (*) What they lack in eyesight is made up for with a very keen sense of smell and very acute hearing (*) See in color, thought to help them find food because a lot of what they eat is fruit and berries
- Here are some of the basics on black bear biology and life history information: The home ranges of bears vary widely by season, habitat quality, and reproductive status. Males ranges may reach in upwards of 850 square miles and females up to about 100 square miles. (*)
- 75% of the bearâs diet consists of vegetative matter - ranging from grasses to fruits to nuts to agricultural crops. The bearâs spring diet consists primarily of succulent new plant growth, insects and larvae. Although they are not particularly good hunters, they have been known to prey on small to medium-sized mammals such as rodents and deer fawns.(*)
- 75% of the bearâs diet consists of vegetative matter - ranging from grasses to fruits to nuts to agricultural crops. The bearâs spring diet consists primarily of succulent new plant growth, insects and larvae. Although they are not particularly good hunters, they have been known to prey on small to medium-sized mammals such as rodents and deer fawns.(*)
- 75% of the bearâs diet consists of vegetative matter - ranging from grasses to fruits to nuts to agricultural crops. The bearâs spring diet consists primarily of succulent new plant growth, insects and larvae. Although they are not particularly good hunters, they have been known to prey on small to medium-sized mammals such as rodents and deer fawns.(*)
- In preparation for late fall/early winter denning, bears consume a variety of foods high in carbohydrates that are stored as fat. (*) One of the most important fall food sources are oak acorns (Acorns are one species of hard mast). (*) Bears may gain as much as 1-2 pounds per day beginning in late summer through the fall in preparation for denning. (*) Field and sweet corn, peaches, cherries, apples, and other fruits attract bears especially when natural food sources are scarce.(*)
- As a mechanism to circumvent food shortages and severe winter weather conditions, bears enter a period of dormancy for up to 6 months. (*) Bears enter winter dens anywhere between October and January. The time of entry depends upon their reproductive status, the weather, and available foods. They use a variety of den forms such as rock cavities, excavations, brush piles, trees, and snags. In western Virginia, they use an unusually high percentage of tree dens (~69%). In eastern Virginia, they more often found in ground dens. (*) During hibernation, bears do not eat, drink, defecate, or urinate. (*) Their body temperatures drop only 5-8 degrees Celsius. Other hibernators' body temperatures come within 1 degree C of the surrounding temperature. (*) Bear metabolisms slow, their heart rates decrease, and they may lose close to 30% of their body weight during the denning period. Bears often den in confined spaces to reduce heat loss and conserve energy. (*) Unlike most hibernating mammals that appear lethargic when disturbed, bears are easily aroused and can run from their winter dens. (*)
- As a mechanism to circumvent food shortages and severe winter weather conditions, bears enter a period of dormancy for up to 6 months. (*) Bears enter winter dens anywhere between October and January. The time of entry depends upon their reproductive status, the weather, and available foods. They use a variety of den forms such as rock cavities, excavations, brush piles, trees, and snags. In western Virginia, they use an unusually high percentage of tree dens (~69%). In eastern Virginia, they more often found in ground dens. (*) During hibernation, bears do not eat, drink, defecate, or urinate. (*) Their body temperatures drop only 5-8 degrees Celsius. Other hibernators' body temperatures come within 1 degree C of the surrounding temperature. (*) Bear metabolisms slow, their heart rates decrease, and they may lose close to 30% of their body weight during the denning period. Bears often den in confined spaces to reduce heat loss and conserve energy. (*) Unlike most hibernating mammals that appear lethargic when disturbed, bears are easily aroused and can run from their winter dens. (*)
- (*) Sows generally become sexually mature at age 3 or 4. Cubs generally remain with sow through first summer and den with her during following winter, (*) so sows typically reproduce every other year. (*) In Virginia, the breeding season falls between mid-June and mid-August, with a peak in mid-late July. (*) Bears are delayed implanters, which means that the fertilized eggs postpone any growth in the uterus and do not actually implant on the uterine wall until early December. (*) Delayed implantation ensures that cubs are born in the winter den around the end of January, and that gestation period occurs when females are in their best nutritional condition. (*) Litter sizes in Virginia average 2.5 cubs per litter with a range between 1 and 4 cubs. Black bear cubs in Virginia experience about a 25% mortality rate during their first year. (*)
- (*) Sows generally become sexually mature at age 3 or 4. Cubs generally remain with sow through first summer and den with her during following winter, (*) so sows typically reproduce every other year. (*) In Virginia, the breeding season falls between mid-June and mid-August, with a peak in mid-late July. (*) Bears are delayed implanters, which means that the fertilized eggs postpone any growth in the uterus and do not actually implant on the uterine wall until early December. (*) Delayed implantation ensures that cubs are born in the winter den around the end of January, and that gestation period occurs when females are in their best nutritional condition. (*) Litter sizes in Virginia average 2.5 cubs per litter with a range between 1 and 4 cubs. Black bear cubs in Virginia experience about a 25% mortality rate during their first year. (*)
- Summer is the breeding season for the black bear, a time of year when bears are naturally on the move. Adult males may roam well beyond their normal range searching for mates. Adult females breed every other year and give birth from mid-January to early February. Females that have reared cubs for the past year and a half are ready to breed again, and the young (yearlings or 1 œ year old bears) are ready to be on their own and establish new home ranges. While young females generally establish a home range near that of their mother, young males may roam widely to establish a new home range.
- (*) There is very limited information on bear population numbers and distribution in Virginia prior to 20th Century (*) Bears were abundant throughout Virginia in colonial times. (*) Following the American Revolution (1775-1783), Virginia offered a bounty on bears and bear numbers appeared to be declining by the mid 1800âs. With increased habitat clearing and continued human population growth, bears moved to the less desirable areas such as the mountains and the swamps. (*) By 1900, records indicate they were near extinction statewide. (*) Despite todayâs healthy bear populations, it has not always been that way. Black bears probably were abundant and occurred throughout pre-colonial Virginia. Prior to European settlement, Native Americans throughout the southeastern United States used bears for food, clothing, weapons, and ornaments. Rapidly growing human populations, habitat changes (deforestation), and over hunting (especially market hunting) had early negative impacts on Virginiaâs bear population. By 1739, bears were only found in the western mountains and swamp areas of Virginia. During the mid-1800s, bear skins and meat still were commonly shipped to other markets from rail yards in western Virginia. Bounties, offered since the American Revolution, provided added incentive for the demise of bear populations in Virginia. By 1900, bears were practically extinct in Virginia. Only remnant populations remained in the Dismal Swamp and in the mountainous regions of some western counties.
- (*) There is very limited information on bear population numbers and distribution in Virginia prior to 20th Century (*) Bears were abundant throughout Virginia in colonial times. (*) Following the American Revolution (1775-1783), Virginia offered a bounty on bears and bear numbers appeared to be declining by the mid 1800âs. With increased habitat clearing and continued human population growth, bears moved to the less desirable areas such as the mountains and the swamps. (*) By 1900, records indicate they were near extinction statewide. (*)
- It is important to understand a few basics about bear population dynamics and what populations are capable of. (*) First of all, bear populations tend to grow very slowly - their maximum population growth potential is about 25% per year, however, most populations do not grow this quickly - especially those in hunted areas. (*) (*) Hunting mortality is additive, which means that bears killed by hunters are in addition to those that would naturally have died. The alternative to additive mortality is compensatory mortality where hunters are harvesting bears that would have died naturally that year anyway. Their low population growth rates are offset by their relatively high survivorship. (*) Bear populations are slow to recover from low densities and do not experience âboom and bustâ phenomena as other wildlife species do. (*)
- If the attractant remains, different bears will show up.
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