Are nutritional limitations in northern ungulates paradoxical?

Nutritional paradoxes are conclusions about nutritional ecology that seem counterintuitive or self-contradictory at first, but upon deeper investigation turn out to be well supported (i.e., they have a solution). We summarize 7 scenarios for northern ungulates in which the presence or absence of a nutritional limitation seems paradoxical. We then deconstruct each perceived paradox, reducing it to its basic assumptions, and illustrate how the contradictions characterizing each paradox can be resolved through the lens of nutritional ecology. We also detail how nutritional constraints associated with each paradox have resulted in evolved life-history traits, physiology, and behavior that allow northern ungulates to persist in their environments. Our work illustrates how nutritional paradoxes can mask nutritional limitations for northern ungulates, which can lead to erroneous conclusions, with the potential to jeopardize their management and conservation. We conclude that nutritional paradoxes can be resolved with strong foundational knowledge of nutritional ecology. We recommend studies aiming to evaluate the role of nutrition relative to individual performance or population productivity consider the potential for nutritional paradoxes to mask important roles of nutrition.