Follow the leader: social cues help guide landscape-level movements of American black bears (Ursus americanus)

Solitary, facultative migrating animals must make decisions each year on whether, when, and where to migrate. Factors influencing individuals in their movement choices are poorly understood. American black bears (Ursus americanus Pallas, 1780) commonly migrate in late summer to areas of concentrated foods before winter denning; some bears also move long distances to dens. We radio-tracked seasonal migrations of >200 bears in Minnesota, USA, over 10 years. We observed concurrences in movements that suggested social coordination among individuals, including (i) individuals with neighboring summer ranges traveling to the same distant feeding and (or) denning areas, (ii) shared travel routes with use staggered through time, and (iii) instances of ≥2 individuals traveling in loose tandem over tens of kilometres. We sought to explain the mechanism for these coordinated migrations by comparing our observations to the predictions of six hypotheses: instinct, landscape morphology, habitat gradients, long-distance olfaction, maternal teaching, and conspecific cueing. The most parsimonious explanation was that bears follow other bears, with social cueing likely mediated through chemical communication. Males likely play a key role in social transmission of knowledge of the nutritional landscape via a system of travel routes and information centers that benefits the entire population.

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Temporal variation in food habits of the American Black Bear (Ursus americanus) in the boreal forest of northern Ontario

The Canadian Field-Naturalist ◽

10.22621/cfn.v127i2.1442 ◽

2013 ◽

Vol 127 (2) ◽

pp. 118 ◽

Cited By ~ 5

Author(s):

Derrick A. Romain ◽

Martyn E. Obbard ◽

James L. Atkinson

Keyword(s):

Temporal Variation ◽

Food Habits ◽

Ursus Americanus ◽

Late Summer ◽

Black Bear ◽

Black Bears ◽

Northern Ontario ◽

American Black Bear ◽

American Black ◽

American Black Bears

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.

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A distance-based analysis of habitat selection by American black bears (Ursus americanus) on the Bruce Peninsula, Ontario, Canada

Canadian Journal of Zoology ◽

10.1139/z10-072 ◽

2010 ◽

Vol 88 (11) ◽

pp. 1063-1076 ◽

Cited By ~ 11

Author(s):

Martyn E. Obbard ◽

Melissa B. Coady ◽

Bruce A. Pond ◽

James A. Schaefer ◽

Frank G. Burrows

Keyword(s):

Habitat Selection ◽

Ursus Americanus ◽

Deciduous Forest ◽

Mixed Forest ◽

Late Summer ◽

Black Bears ◽

Home Ranges ◽

Isolated Population ◽

American Black ◽

American Black Bears

Because of their wide-ranging habits, conserving large carnivores such as American black bears ( Ursus americanus Pallas, 1780) often depends on understanding habitat needs beyond the boundary of protected areas. We studied habitat selection by black bears in the vicinity of Bruce Peninsula National Park, Ontario — a small, isolated population whose persistence appears dependent on habitat on lands outside the Park. We used an approach based on Euclidean distances to document seasonal habitat selection at two spatial scales and to identify candidate habitat types for protection. Adult females selected dense mixed forests to establish home ranges within the population range, whereas subadults and yearlings selected dense deciduous forests. Within home ranges, adults selected dense mixed forest in spring–summer and dense deciduous forest in late summer – fall. Subadults selected dense deciduous forest, marsh, dense mixed forest, and water during the spring–summer and avoided developed lands and roads. Yearlings selected dense mixed forest, dense deciduous forest, and sparse forests in spring–summer and dense deciduous forest and dense mixed forest in late summer – fall. The selection of dense deciduous and dense mixed forest stands, especially at the broader scale, suggests that strategies to ensure persistence of this isolated population should focus on protecting the integrity of these stands.

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