WildFact
›
Information Section
›
Terrestrial Wild Animals
›
Carnivorous and Omnivores Animals, Excluding Felids
›
Bears
Black Bears
Black Bears
|
Black Bears
|
Landscape Partitioning and Spatial Inferences of Competition between Black and Grizzly Bears
Abstract Population effects of competition between large carnivore species may be evident by contrasting actual distributions of putative competitors against predictions of inherent landscape quality for each species. Such comparison can be insightful if covariation with external factors known to influence the occurrence, density, or persistence of each species over space and time can be controlled. We used systematically-distributed DNA hair-trap stations to sample the occurrence of black bears Ursus americanus and grizzly bears U. arctos across 5496 km² in southeastern British Columbia, Canada. We describe interspecific landscape partitioning according to terrain, vegetation and land-cover variables at 2 spatial scales. We developed multivariate models to predict the potential distribution of each species. At sampling site-session combinations that detected either species, we then investigated whether the expected or actual occurrence of each influenced the likelihood of detecting the other while controlling for human influence and inherent landscape quality. Black bears were more likely than grizzly bears to occur in gentle, valley bottom terrain with lower proportions of open habitats. Each species also was detected less frequently with the other species than predicted by their respective models; however, the strength of this relationship decreased as landscapes became more characteristic of black bear habitat. As landscapes showed higher inherent potential to support grizzly bears, black bears occurred more than model prediction in areas with higher human access and proximity to major highways but less in national parks. As potential to support black bears increased, grizzly bears occurred more than model prediction only in national parks and less with increasing human access and proximity to major highways. Results suggest that competition is occurring between the species, and that the differential response of each species to human disturbance or excessive mortality may influence the outcome and hence landscape partitioning. Moreover, black bears are more likely to benefit from human encroachment into landscapes of high inherent value for grizzly bears than vice versa. Conservation implications relate to potential mediating effects of habitat and human influence on competitive interactions between the species  EVIDENCE FOR FATAL INJURY INFLICTED ON A FEMALE BLACK
BEAR BY A MOOSE
Abstract: Predators may risk injury or death when attacking large prey. Black bears (Ursus americanus) are known predators of young moose (Alces alces), which may be defended from predators by their mothers. We report evidence that a radio-collared adult female black bear was killed by a cow moose during a presumed predatory attack. This observation suggests that moose are dangerous prey for black bears. Link : EVIDENCE FOR FATAL INJURY INFLICTED ON A FEMALE BLACK BEAR BY A MOOSE 
This is one great and funny photo, bears can really enjoy life too time to time...
 *This image is copyright of its original author Quote: "In Florida, one could coin a new term for black bears: Pets. Or maybe: Pests. Some have gotten into the habit, it seems, of visiting neighborhoods there, and on Thursday, one was caught literally hanging around -- in a Daytona Beach man's hammock. "He got in the hammock like he was a tourist or something," homeowner Vincent James told CNN affiliate WESH. Usually, James is the one lounging on his back in the white rope mesh hanging between two trees. The bear enjoyed the respite enough to savor it. He -- or she -- stayed in the hammock for about 20 minutes, said photographer Rafael Torres, who snapped pictures of the bear from 60 feet away. Torres' presence did not seem to disturb the wild animal's repose. Residents say the bear has been scrounging for food in the neighborhood since Wednesday, ripping through garbage cans and knocking down bird feeders." https://edition.cnn.com/2014/05/31/us/florida-bear-in-hammock/index.html Of course it´s problematic if bears get too comfortable to be close to people, but still, damn this bear obviously knows how to relax!
There are a lot of funny posts on this thread.
However, there is not much on Black Bear attacks. Here is an infamous case. "A black bear that may have learned to prey on humans killed a woman and injured her husband at a provincial park in northern Ontario. Police and wildlife officials were on the hunt for the wounded bear Wednesday and campers have been ordered out of the back country of Missinaibi Lake Provincial Park. Jacqueline Perry and Mark Jordan, both 30, were attacked at a campsite in the provincial park about 80 kilometres north of Chapleau. Ontario Provincial Police said that while the bear was attacking Perry, her husband managed to stab it with a Swiss Army knife in a frantic effort to keep it from dragging his wife into the woods. Perry was a family doctor at Grandview Medical Centre in Cambridge, Ont. The couple were on a two-week holiday, camping and kayaking at a remote campsite when the black bear attacked. OPP Const. Karen Farand said after fighting off the bear, the injured Jordan carried his wife to their kayak and started paddling to the nearest campsite. He yelled for help, and a father and son from Pennsylvania heard him and took Perry into their boat. They soon flagged down another boat with a doctor from North Carolina and an off-duty police officer on board. The doctor tried to treat Perry while the boat continued on to the park office about 10 kilometres away, but Perry succumbed to her injuries." https://www.cbc.ca/news/canada/black-bear-kills-woman-camper-north-of-chapleau-ont-1.556281 Here is a movie loosely based on that incident. 
Two asiatic black bears fighting. scroll right for more photos.
" target="_blank" class="post_link"> 
One very good video about differences (and similarities) in between black bears and brown bears. I posted this already in brown bears thread, but thought to put it also here.
Here are some natural says to deter Black Bears.
One way is to yell at them. First video starts at 2:16 
The Weight of the American Black Bear
This should serve as an calculation for the total average weight of the species "Ursus Americanus"; I'll list the datasets below! 1. Harlow (1961) - Florida Black Bear: 305lbs for 16 males; 189lbs for 12 females 2. Maehr (2001) - Florida Black Bear: 139.16kg for 13 males; 87.24kg for 21 females ... Mexican Black Bear: 108.92kg for 13 males; 65.44kg for 13 females 3. Rogers et al. (1976) - Michigan Black Bear: 287lbs for 19 males; 183lbs for 16 females 4. Jonkel and Cowan (1971) - Montana Black Bear: 211lbs for 43 males; 125lbs for 76 females 5. Harlow (1961) - New Hampshire Black Bear: 263lbs for 19 males; 183lbs for 11 females 6. Sauer (1975) - New York Black Bear: 251lbs for 16 males; 165lbs for 30 females 7. Collins (unpublished data) - North Carolina Black Bear: 368lbs for 49 males; 197lbs for 37 females 8. Alt (1980) - Pennsylvania Black Bear: 402lbs for 72 males; 203lbs for 93 females 9. Willey (1978) - Vermont Black Bear: 238lbs for 14 males; 109lbs for 28 females 10. Poelker and Hartwell (1973) - Washington Black Bear: 221lbs for 10 males; 142lbs for 10 females 11. McLellan (2011) - British Columbia Black Bear: 95.64kg for 143 males; 70.45kg for 79 females 12. Noyce and Garshelis (1998) - North-Central Minnesota Black Bear: 124.95kg for 77 males; 69.9kg for 163 females 13. Beckmann and Berger (2003) - Lake Tahoe/Nevada Black Bear: 131.88kg for 48 males; 79.22kg for 14 females 14. Bartareau et al. (2012) - Northern Canada Black Bear: 126.3kg for 100 males; 89.24kg for 39 females 15. Dobey et al (2010) - Georgia Black Bear: 103.3kg for 28 males; 53.3kg for 32 females ... Florida Black Bear: 138.5kg for 14 males; 64.6kg for 10 females Total Average Weight: ~123.39kg (~272.03lbs) for males (n=694) and ~73.54kg (~162.13lbs) for females (n=684). If you find additional sources, feel free to share them; the goal is to update it regularly and increase the sample size for both genders!
Black Bear age studies
"We designated bears in their second year of life as yearlings, 2- and 3- year olds as subadults, and >4-year olds as adults" source: Lee, Daniel J., and Michael R. Vaughan. “Dispersal Movements by Subadult American Black Bears in Virginia.” Ursus, vol. 14, no. 2, 2003, pp. 162–170. JSTOR, http://www.jstor.org/stable/3873016. Accessed 15 May 2021. "Survival rates for subadult black bears tend to be lower than for adult black bears in North American populations (Bunnell and Tait 1981, Schwartz andFranzmann 1991, Beringer et al. 1998). Subadult bears, especially males, are capable of traveling long distances and have larger home ranges, making them more susceptible to harvest, automobile collisions, and other anthropogenic of mortality (Schwartz and Franzmann 1992). "Additionally, we attached ear tag transmitters or radiocollars to a sample of subadult bears during the handling process. All transmitter-equipped 1-, 2-, and 3-year-old males and l-year-old females received ear tag transmitters, while 2- and 3-year-old females received ear tagtransmitters (i.e., bear weight <45 kg) or radiocollars (i.e., bear weight >45 kg)." source: Lee, Daniel J., and Michael R. Vaughan. "Yearling and subadult black bear survival in a hunted Virginia population." The Journal of wildlife management 69.4 (2005): 1641-1651. "Black bears will occasionally kill and cannibalize other bears. Most cannibalization documented in Maine has been on subadult bears (2-3 years of age)" "Adult males (4 years of age and older) often dominate food sources, and adults are known to prey on smaller bears. However, black bears do not actively defend territories." "Female bears remain within or close to the area they were born in, but males disperse as subadults, usually at 2-4 years of age in Maine (Hugie 1982, MDIFW file data)." "By the time female bears are adults (4 years of age), their survival increases to nearly 100% in the absence of hunting." source: McLaughlin, Craig R. Black bear assessment and strategic plan 1999. The Department, 1999 As can be seen, sub-adult Black Bears (age 1-3 years) have lower survival rates than adult Black Bears (age 4 and above) with or without human interference.
Black Bear with a Humboldt Squid.
 *This image is copyright of its original author  *This image is copyright of its original author  *This image is copyright of its original author https://tofinophotography.wordpress.com/...ldt-squid/
American Black Bear scared by an animatronic.
Japanese Black Bear scared by an animatronic. The obvious difference is that the Japanese are using animatronics to scare Bears from raiding their crops. The American Black Bear was likely scared away from the house, or this was just a funny accident where the Bear conveniently found the animatronic.
Here is a Black Bear eating a Sturgeon in Shasta Lake, California.
 *This image is copyright of its original author https://activenorcal.com/dealing-with-be...ilderness/ |
| Users browsing this thread: |
| 6 Guest(s) |