Antipredatory Strategies of Anurans: An Updated Conceptual Review

Abstract

Anurans exhibit an extraordinary diversity of antipredatory strategies, shaped by their global distribution, ecological breadth, and complex evolutionary history. Despite numerous catalogs, existing reviews have predominantly focused on adult stages and specific strategies, often neglecting ontogenetic diversity, behavioral nuances, and the non-linear structure of predation. Consequently, there is an urgent need to identify conceptual gaps capable of guiding studies on these behaviors, principally because the current literature remains largely anecdotal and highly hypothetical, lacking formal tests to elucidate their diverse eco-evolutionary aspects. Here, through a systematic review of antipredatory strategies in anurans, we present an updated integrative framework that systematically classifies anuran defenses against predators into a three-level system: non-behavioral strategies (comprising coloration, morphological structures like macroglands and skeletal processes, and chemical secretions), individual behavioral strategies (encompassing evasion, intimidation through acoustic or postural displays, counterattack, protection such as phragmosis, and disinterest behaviors like death feigning), and group behavioral strategies (including intraspecific and interspecific associations). These strategies are functionally organized according to five main phases of antipredation, anti-detection, anti-approach, anti-identification, anti-capture, and anti-consumption, yet the framework explicitly discourages a rigid sequential interpretation, as defensive responses often overlap or occur non-linearly. A central component of this proposal is the concept of synergetic coupling, wherein discrete antipredatory elements are integrated into complex multimodal and morphophysiological displays, such as deimatic behavior, aggressive synergy, and staging. Crucially, these couplings frequently transcend the strictly defensive context, manifesting as eco-evolutionary synergies where antipredatory functions are coupled with other vital biological processes such as thermoregulation, reproduction, or communication. We further highlight neglected strategies, including chemical mimicry, bodyguard interactions involving mutualistic or mutualistic/commensal associations with bromeliads, ants, termites, or spiders, and the functional relevance of group-level defenses. By addressing critical conceptual shortfalls, this review refines the conceptual boundaries of anuran antipredatorial strategies and provides a unified, flexible basis for future comparative, macroecological, and macroevolutionary studies across vertebrates. This framework shifts the scientific focus toward a rigorous, hypothesis-driven experimental approach to validate the functional effectiveness of these diverse adaptive traits across varying ecological contexts.