Caroline M. Abramowitz Wesley W. Boone Stephen N. Harris Chloe E. Horton Meghan P. Keating Dana L. Nelson Samantha N. Smith Katelyn N. Steen Erin K. Buchholtz David S. Jachowski John M. Nettles 2026 <h3 id="mam70014-sec-0001-title" class="article-section__sub-title section1">Introduction</h3><p>American black bears (<i>Ursus americanus</i>) have been documented to have top-down effects, both consumptive (through predation) and nonconsumptive (through fear effects). However, their behavioural and dietary adaptability has led to uncertainty about the conditions under which these may occur.</p><h3 id="mam70014-sec-0002-title" class="article-section__sub-title section1">Objectives</h3><p>We aimed to (1) investigate when, where, and how often black bears influence lower trophic levels, and (2) critically assess the experimental design of such studies to determine trends and biases.</p><h3 id="mam70014-sec-0003-title" class="article-section__sub-title section1">Methods</h3><p>We conducted a systematic literature search and used linear mixed-effects models to assess the relationships among prey age class, the presence of other large carnivores, and the percentage of ungulate mortality due to black bears. We also summarised the measured effects of black bears on other carnivores and the results of any experimental studies.</p><h3 id="mam70014-sec-0004-title" class="article-section__sub-title section1">Results</h3><p>We found a strong negative relationship between puma presence and the percentage of ungulate mortality due to black bears, but only in areas with at least one other large carnivore (e.g., wolves). Among 16 studies of black bears' impacts on other carnivores, most documented negative behavioural effects. While only 5% of studies had strong experimental design, bear removal consistently increased juvenile ungulate survival.</p><h3 id="mam70014-sec-0005-title" class="article-section__sub-title section1">Discussion and Synthesis</h3><p>Our findings highlight black bears' strong top-down effects, resembling or exceeding those of other large carnivores. These effects were greatest when no other large carnivores were present, but as highly effective kleptoparasites, black bears can alter the feeding habits of other large carnivores. Thus, we argue that ‘apex’ is a conditional state, not a species-wide status.</p> application/pdf 10.1111/mam.70014 en Wiley The American black bear (Ursus americanus) as an apex predator: Investigating the ecological role of the world’s most abundant large carnivore article