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Abstract Phenological synchrony enables species to occur when conditions are optimal for survival. While phenological synchrony between butterflies and their host plants has been extensively documented, the importance of phenology in maintaining interspecies interactions, such as mimicry, is less understood. Mimicry occurs when a species (i.e. the mimic) evolves a phenotypic resemblance to an unpalatable species (i.e. the model), resulting in protection against predation for the mimic. Theory predicts that in Batesian mimicry systems, models should appear seasonally before their mimics to give predators sufficient time to learn, recognize, and avoid their aposematic signal (i.e. model-first hypothesis). Here, we use citizen science data from iNaturalist to test these long-standing predictions. To understand how mimicry influences the evolution of different phenological strategies, we estimate onset phenology in two systems: the defended model species Battus philenor and its classic Batesian mimic Limenitis arthemis astyanax, and the more complex system consisting of Mullerian co-mimics Danaus plexippus and Limenitis archippus. Our results support the model-first hypothesis and demonstrate that unpalatable models appear significantly before their mimics across large geographical scales. This research highlights a new avenue for utilizing large-scale citizen science datasets to address long-standing questions about how phenology impacts complex ecological interactions.
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This content will become publicly available on January 1, 2026
Is temporal synchrony necessary for effective Batesian mimicry?
Batesian mimicry occurs when palatable mimics gain protection from predators by evolving a phenotypic resemblance to an aposematic model species. While common in nature, the mechanisms maintaining mimicry are not fully understood. Patterns of temporal synchrony (i.e. temporal co-occurrence) and model first occurrence have been observed in several mimicry systems, but the hypothesis that predator foraging decisions can drive the evolution of prey phenology has not been experimentally tested. Here, using phenotypically accurate butterfly replicas, we measured predation rates on the chemically defended model speciesBattus philenorand its imperfect Batesian mimicLimenitis arthemis astyanaxunder four different phenological conditions to understand the importance of temporal synchrony and model first occurrence in mimicry complexes. We predicted that protection for mimics increases when predators learn to avoid the models' aposematic signal right before encountering the mimic, and that learned avoidance breaks down over time in the model’s absence. Surprisingly, we found that asynchronous model first occurrence, even on short time scales, did not provide increased protection for mimics. Mimics were only protected under conditions of temporal synchrony, suggesting that predators rely on current information, not previously learned information, when making foraging decisions.
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- Award ID(s):
- 2242864
- PAR ID:
- 10626724
- Publisher / Repository:
- The Royal Society
- Date Published:
- Journal Name:
- Proceedings of the Royal Society B: Biological Sciences
- Volume:
- 292
- Issue:
- 2039
- ISSN:
- 1471-2954
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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