Spring diet of American black bears (Ursus americanus) in a moose (Alces alces) – woodland caribou (Rangifer tarandus caribou) system in northern Ontario, Canada

2021 ◽  
pp. 721-728
Author(s):  
A.A.D. McLaren ◽  
S.E. Jamieson ◽  
M. Bond ◽  
A.R. Rodgers ◽  
B.R. Patterson

American black bears (Ursus americanus Pallas, 1780) are opportunistic foragers, and across most of their range in North America, their diet is predominantly vegetation with limited consumption of vertebrates and invertebrates. However, they are also predators of ungulates, especially neonates, with regional variation in the amount of predation pressure they exert. We used scat analysis to examine the diet of black bears during the calving season in a moose (Alces alces (Linnaeus, 1758)) – woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) system in the Boreal forest of northern Ontario, Canada. Bears consumed herbaceous plants (46.5%), fruits and (or) seeds (20.0%), moose (3.3% adults; 4.3% calves), American beaver (Castor canadensis Kuhl, 1820; 8.5%), and insects (mostly ants; 4.2%). Bears had the highest consumption of moose and beaver in early spring, before switching to a more vegetation-dominated diet. We did not detect evidence of caribou consumption. Based on our results, black bear consumption of moose, particularly neonates, may warrant further investigation.

2013 ◽  
Vol 127 (2) ◽  
pp. 118 ◽  
Author(s):  
Derrick A. Romain ◽  
Martyn E. Obbard ◽  
James L. Atkinson

We used scat analysis to investigate temporal variation in the food habits of American Black Bears (Ursus americanus) in the boreal forest of northern Ontario. Specifically, we examined whether there was a seasonal shift in foraging over three years (1990–1992) and which foods, if any, varied in occurrence among years. American Black Bears ate foods ranging from green vegetation in the spring to ants in mid-summer and berries and nuts in late summer and fall. Late summer berry forage, especially blueberries (Vaccinium spp.), varied greatly among years. American Black Bears in northern Ontario consumed a variety of foods opportunistically. Understanding how American Black Bears in northern Ontario exploit food resources and how these food items vary among years can provide insights into demographic processes and help wildlife managers better anticipate changes in the structure of the harvest of American Black Bears and in human–bear conflict levels. In northern Ontario, forest management practices that increase the availability of early successional species would be beneficial to American Black Bear populations.


2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Matthew A. Mumma ◽  
Guillaume Bastille-Rousseau ◽  
Steve E. Gullage ◽  
Colleen E. Soulliere ◽  
Shane P. Mahoney ◽  
...  

2011 ◽  
Vol 89 (4) ◽  
pp. 267-277 ◽  
Author(s):  
A.D.M. Latham ◽  
M.C. Latham ◽  
M.S. Boyce

Populations of woodland caribou ( Rangifer tarandus caribou (Gmelin, 1788)) have declined across much of their range. Wolves ( Canis lupus L., 1758) are believed to be responsible for the majority of mortality in adult female caribou; however, we hypothesize that other predators such as black bears ( Ursus americanus Pallas, 1780) may be important contributors to calf mortality. We assessed habitat selection by black bears and spatial relationships of caribou – black bears during the caribou calving season in northeastern Alberta, Canada. Black bears avoided bogs and fens, while selecting upland mixed woods and various industrial features. Conversely, caribou showed strong selection for bogs and fens relative to bears, supporting the hypothesis that caribou in the boreal forest attempt to minimize predation risk by selecting peatlands to avoid areas frequented by predators. However, habitat selection by individual black bears was highly variable and some bears selected habitats similar to those selected by caribou, i.e., bogs and fens. Bears that specialize on foraging in peatlands might be responsible for some of the predation on caribou calves. Because declines in caribou populations have resulted from a combination of high adult female and calf mortalities, management actions to conserve woodland caribou should consider the entire suite of potential predators rather than focusing only on wolves.


2020 ◽  
Vol 101 (2) ◽  
pp. 564-573
Author(s):  
J Bernardo Mesa-Cruz ◽  
Colleen Olfenbuttel ◽  
Michael R Vaughan ◽  
Jaime L Sajecki ◽  
Marcella J Kelly

Abstract We assessed the effects of cub age, litter size, and sex, on body mass (BM), absolute and relative growth rates (AGR, RGR), opening of ears and eyes, and deciduous teeth eruption from 129 cubs of American black bears (Ursus americanus) born at Virginia Tech’s Black Bear Research Center. Specific ages, related to maternal food consumption, and litter size, best described BM, AGR, RGR, and ear and eye development. Overall, newborns weighed ~0.44 kg at birth and increased ~9-fold by ~14 weeks. Twins were greater in BM than single cubs and triplets. Single and triplet cubs had higher AGR and RGR than twins after mothers resumed food consumption post-hibernation. Newborns displayed RGR > 3.5% that decreased until den emergence (RGR < 3.5% after emergence). RGR differed among litter sizes, particularly after den emergence. Ear and eye opening occurred concurrently at ~44 days of age, while teeth erupted ~10 days later. Single cubs experienced delayed development of these organs compared to other litter sizes. Postnatal developmental differences between black bears and other carnivores likely stem from strategies allowing black bears to minimize energy expenditure during the gestational period when hibernating.


2010 ◽  
Vol 74 (8) ◽  
pp. 1403-1413 ◽  
Author(s):  
L.F.C. Brito ◽  
P.L. Sertich ◽  
G.B. Stull ◽  
W. Rives ◽  
M. Knobbe

2019 ◽  
Vol 55 (1) ◽  
pp. 74 ◽  
Author(s):  
Indrani Sasmal ◽  
Nicholas P. Gould ◽  
Krysten L. Schuler ◽  
Yung-Fu Chang ◽  
Anil Thachil ◽  
...  

Animals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1123
Author(s):  
Lynn L. Rogers ◽  
Linda McColley ◽  
Janet Dalton ◽  
Jim Stroner ◽  
Douglas Hajicek ◽  
...  

Denning behavior has long remained the least observed aspect of bear behavior. During 2010–2013, we used webcams, microphones, the internet, and 14,602 h of archived video to document the denning behaviors of two adult wild black bears (Ursus americanus) as they gave birth and cared for four litters through six winters in northeastern Minnesota. Observations included types of dens, labor, pre-parturient genital swelling, birthing positions, post-partum vocalizations, mothers removing amniotic tissues and warming newborn cubs in sub-freezing temperatures, frequency of nursing, cubs establishing nipple order, yearlings suckling, the ingestion of snow and icicles, the ingestion of foot pads, urination and defecation in latrine areas, toilet-licking, eye opening, reciprocal tongue-licking, play, rapid eye movement (REM) sleep and possible dreaming, and reactions to wildlife intruders. The use of this new method for observing natural bear dens allowed the identification of many behaviors undescribed for any species of wild bear in dens. We also discuss the need for future studies and how the depth and duration of black bear hibernation varies with body condition and geographic region.


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