From lagging to leading: Increased phenological asynchrony in a Batesian mimicry complex

Climate change disrupts ecological systems by shifting species distributions and altering phenological patterns, significantly affecting interspecific interactions like Batesian mimicry. Effective mimicry relies on the spatial and temporal overlap between mimics and their models to deter predators. This idea has persisted despite emerging data that challenges it. To assess phenological position and flight season changes, we extracted flight season data for model bumblebee species and mimicking hoverflies for the Scandinavian peninsula, spanning a little over century-and-a-half. We estimated shifts in the annual mean flight season and the phenological order of emergence in our Batesian system while accounting for yearly survey variations. We found compelling evidence of a temporal shift in flight season dynamics in the Batesian system. Mimics historically flew significantly earlier than models, but in more recent years, there has been a pronounced trend towards mimics flying later than m..., Flight season data (citizen-science observations and museum specimens) of model bumblebees and mimic hoverflies was extracted from Norwegian Artsdatabanken (https://www.artsdatabanken.no) and Swedish Artportalen (https://artportalen.se/). The data was cleared off records lacking valid species names and duplicate entries; with start and end dates exceeding one month were deemed invalid and excluded from further analysis., , # From lagging to leading: Increased phenological asynchrony in a Batesian mimicry complex

Dataset DOI: [10.5061/dryad.jwstqjqjw](10.5061/dryad.jwstqjqjw)

## Description of the data and file structure

**1) ModelMimics_raw data file**

*Description: *This Excel spreadsheet contains raw observational data on flight times of model bumblebees and their hoverfly mimics, extracted on 21 June 2023 from two online citizen science and museum specimen databases: Norwegian Artsdatabanken ([https://www.artsdatabanken.no/](https://www.artsdatabanken.no/)) and Swedish Artportalen ([https://www.artportalen.se/](https://www.artportalen.se/)) (refer to the methods section of the paper).  Data were downloaded, translated where necessary (from Norwegian and Swedish), and cleaned for use in our study. Please refer to the methods section of the accompanying paper for further details on data collection and cleaning protocols. The file contains five CSVs, which are described below.

### Files and variables...,