Large mammalian herbivores disrupt demographic compensation along an aridity gradient

Ecologists often assume that demographic rates such as survival and reproduction vary in concert along abiotic gradients, but growing evidence suggests that these rates may change in opposition, leading to demographic compensation. However, it is unclear how biotic interactions such as herbivory may affect the presence or strength of demographic compensation. Here, we employ a series of strong tests for demographic compensation for a common forb species in the presence and absence of large mammalian herbivores. Namely, we test for demographic compensation in Hibiscus meyeri across a rainfall gradient using a large‐scale exclosure experiment that includes or excludes large mammalian herbivores of various sizes (i.e., small, meso‐, and megaherbivores). We found that demographic compensation did not occur while all large mammalian herbivores were present. By contrast, demographic compensation occurred when megaherbivores were excluded, and this discrepancy was driven by an excess of negative correlations between vital rates. Understanding how biotic factors interact with abiotic gradients to modify demographic processes is crucial for understanding the drivers of species population dynamics for broader efforts in conservation and management.