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Post by arctozilla on Jul 24, 2021 10:02:01 GMT -5
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Post by Gorilla king on Jul 25, 2021 11:53:19 GMT -5
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Post by tyrannosaurs on Aug 2, 2021 12:56:49 GMT -5
The Role of American Black Bears and Brown Bears as Predators on Ungulates in North America: Abstract American black bears (Ursus americanus) and brown bears (U. arctos) can be important predators on neonatal ungulates. They prey less commonly on adult ungulates. Bear predation appears to be additive at low ungulate densities and may become compensatory as prey density approaches carrying capacity, K. As such, black and brown bear predation can limit, but generally does not regulate, ungulate populations. Maternal and neonatal physical condition, birth synchrony, and birth mass may predispose neonates to predation or other mortality factors. Though black and brown bear predation is an important proximate cause of ungulate neonatal mortality, habitat quality and quantity are important ultimate factors influencing this dynamic. Manipulating bear populations to enhance ungulate populations may be successful in the short-term if predation is additive, but long-term success has not been demonstrated. www.jstor.org/stable/3873087 |
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Post by tyrannosaurs on Aug 2, 2021 13:08:34 GMT -5
"carnivores inhabiting the study area included wolves, black bears, and grizzly bears. Their prey included moose..." www.jstor.org/stable/3830617There is another study I am not able to access called: Wolf and Brown Bear predation on Togiak Refuge Carbiou. Can someone access it? |
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Post by Gorilla king on Aug 2, 2021 13:16:19 GMT -5
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Post by Gorilla king on Aug 2, 2021 14:46:21 GMT -5
From the source at reply #49:
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Post by tyrannosaurs on Aug 2, 2021 16:40:02 GMT -5
Moose mortality: www.jstor.org/stable/3803140Abstract We investigated causes of mortality and the physical condition of moose (Alces alces gigas) in a multiple-predator system in eastern interior Alaska, USA, from 1998 to 2000. We identified the sources of mortality of calf and cow moose and collected fecundity and fitness data to obtain information on range quality and carrying capacity. Radiocollars were placed on 30 cow moose in 1998 and on 62 moose calves in 1998 (n = 29) and 1999 (n = 33). Estimates of fecundity and fitness parameters indicated that reproductive potential for moose was high, with a twinning rate of 63%, a pregnancy rate of 89%, and above-average body sizes of female and neonate moose. We inferred that range quality may not be a significant limiting factor for this population. We documented low neonate survival through the first 14 weeks of life (28%). Predation was responsible for 92% of known calf mortality; black bears (Ursus americanus; 45%) and grizzly bears (Ursus arctos; 39%) were the major causes of mortality. Despite low population densities in this region, grizzly bears were an important predator on neonates as well as adult female moose. Mean annual calf and adult female moose survival (20% and 88%, respectively) were similar to rates reported in other low-density moose populations in North America. We also estimated from 7 to 12% of the population was harvested annually by humans, and of that, illegal cow harvest constituted at least 33%. Our data suggest that low calf survival, adult mortality from wolf (Canis lupus) and grizzly bear predation, illegal cow harvest, and low predator harvest, all act in concert to maintain this moose population at a low density. |
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Post by tyrannosaurs on Aug 2, 2021 16:45:43 GMT -5
Determining kill rates of ungulate calves by brown bears using neck-mounted cameras: Camera Collars on Brown Bears: Predation of moose (Alces alces) and caribou (Rangifer tarandas) calves by brown bears (Ursus arctos) has been extensively studied, because predation has population implications for both predator and prey species. Existing methods have provided estimates of population-level predation rates, but they have not been able to estimate kill rates by individual bears until recently and the accuracy of these estimates was unknown. Our objectives were to evaluate whether collars equipped with video cameras would be able to record predation events by brown bears and provide useful estimates of ungulate kill rates. We fitted 17 brown bears in the Nelchina Basin of Alaska, USA, with Global Positioning System (GPS) collars equipped with cameras in the spring of 2011, 2012, and 2013. We retrieved the collars in late June of each year to download the video data and associated GPS locations. To compensate for incomplete sampling, we constructed a calf risk model from previous calf mortality studies and used it to predict total calf kills for each bear through the end of June. The camera collars documented kill rates considerably greater than previous estimates. Median handling times by bears were 40 min for caribou calves and 60 min for moose calves. These short handling times should be considered by future researchers when trying to evaluate kill detectability and when factoring calf mortality into population models. We demonstrate that this technology can be successfully applied in the field and provide recommendations on the video sampling intervals necessary to detect predation rates. www.researchgate.net/publication/314487254_Determining_kill_rates_of_ungulate_calves_by_brown_bears_using_neck-mounted_cameras_Camera_Collars_on_Brown_BearsAlso, there is a weird title for a study named: Grizzly bear, ursus actros usurps bison calf, bison bison captured by Wolves. |
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Post by tyrannosaurs on Aug 2, 2021 16:48:27 GMT -5
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Post by Gorilla king on Aug 2, 2021 16:51:39 GMT -5
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Post by tyrannosaurs on Aug 2, 2021 16:59:46 GMT -5
I meant for the name. I should probably check out these other threads more. I just wanted to know if it has anything to do with predation.
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Post by Gorilla king on Aug 2, 2021 17:02:49 GMT -5
I meant for the name. I should probably check out these other threads more. I just wanted to know if it has anything to do with predation. |
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Post by tyrannosaurs on Aug 2, 2021 17:03:45 GMT -5
Alright. Thank you King Kodiak.
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Post by tyrannosaurs on Aug 3, 2021 4:15:53 GMT -5
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Post by arctozilla on Aug 22, 2021 4:33:42 GMT -5
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Post by arctozilla on Aug 22, 2021 4:36:58 GMT -5
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Post by Gorilla king on Aug 22, 2021 9:12:51 GMT -5
Female grizzly kills an adult male elk on 20 July 1977 near Heart Lake. ibb.co/qrDcxLL
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Post by arctozilla on Aug 29, 2021 7:31:44 GMT -5
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Post by arctozilla on Sept 2, 2021 11:19:02 GMT -5
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Post by arctozilla on Sept 2, 2021 11:21:36 GMT -5
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