A systematic review and meta-analysis of eyespot anti-predator mechanisms
- Department of Biology, Faculty of Science, Hokkaido University, Japan
- Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, The University of New South Wales, Australia
- Department of Biological Sciences, Faculty of Science, The University of Alberta, Canada
- Theoretical Sciences Visiting Program, Okinawa Institute of Science and Technology Graduate University, Japan
Figures
Figure 1
A visual summary of three hypotheses that explain the predation avoidance function of eyespot patterns and the predictions that can be derived from these two hypotheses.
The resemblance of eyespots to actual eyes is discussed through the predator mimicry hypothesis and the conspicuous signal hypothesis. The table shows the predictions derived from these two hypotheses. The references of the examples illustrated in the figure: cuckoos and hawks (Davies and Welbergen, 2008; Ma et al., 2018); moths and spiders (Rota and Wagner, 2006); poison frogs (Saporito et al., 2007); ladybugs (María Arenas et al., 2015); plovers (de Framond et al., 2022); lizards (Bateman and Fleming, 2009).
Figure 2
Overview of the dataset.
(a) Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-like flowchart of the systematic literature search for the meta-analysis. (b) and (c) Details of the main moderators examined in the meta-analysis. (d) The phylogenetic tree of bird species included in the meta-analysis, together with the sample sizes and number of effect sizes per species.
Figure 3
Mean effect sizes of (a) overall for conspicuous patterns (eyespots and non-eyespots), (b) effects split by experiments with eyespot versus non-eyespot patterns, and (c) two prey types used in the experiments.
Thick horizontal lines represent 95% confidence intervals, and thin horizontal lines represent 95% prediction intervals. The points in the centre of each thick line indicate the average effect size. k is the number of effect sizes used to estimate the statistics, followed by the number of studies in the brackets.
Figure 4
The relationships between (a) prey conspicuous pattern area (log-transformed) and effect sizes and (b) number of prey conspicuous patterns and effect sizes.
Circle sizes are scaled according to precision, k represents the number of effect sizes. Each fitted regression line is shown as a coloured straight line, and 95% confidence and prediction intervals are shown as dashed and dotted coloured lines, respectively.
Figure 5
The relationships between (a) total pattern area, (b) pattern maximum diameter/length, and (c) total prey surface area and effect sizes.
k shows the number of effect sizes. Each fitted regression line is shown as a solid straight line, and 95% confidence and prediction intervals are shown as dashed and dotted lines, respectively.
Figure 6
Mean effect sizes of total prey shape types.
Thick horizontal lines represent 95% confidence intervals, and thin horizontal lines represent prediction intervals. The points in the centre of each thick line indicate the average effect size. k shows the number of effect sizes.
Figure 7
Funnel plot and relationships between effect Sizes, effective sample size, and publication year.
(a) Funnel plot using effect size and its inverse standard error. The relationship between effect sizes and (b) the square root of the inverse of effective sample size and (c) publication year. In (b) and (c), circle sizes are scaled accordingly to precision, and k represents the number of effect sizes. Each fitted regression line is shown as a straight line, and 95% confidence and prediction intervals are shown as dashed and dotted lines, respectively.
Figure 8
The relationship between (a) effect sizes and the square root of the inverse of effective sample size and (b) relationship between effect sizes and publication year.
Both plots were based on the multi-moderator model. k shows the number of effect sizes. Each fitted regression line is shown as a solid straight line, and 95% confidence intervals and prediction intervals are shown as dashed and dotted lines, respectively.
Tables
Table 1
Descriptions of the population, intervention, comparator, and outcome (PICO) were used to define the scope of this study.
| PICO | Description |
|---|---|
| Population | Birds as predators and butterflies, moths, caterpillars, and their models as prey |
| Intervention | Presenting eyespot or conspicuous pattern stimulus to birds |
| Comparator | Presenting stimulus that is neither eyespot nor conspicuous patterns |
| Outcome | Avian behavioural responses to eyespot or conspicuous pattern stimuli The probability of prey surviving or being attacked (for the stimuli) |
Additional files
-
Supplementary file 1
Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-EcoEvo Checklist.
- https://cdn.elifesciences.org/articles/96338/elife-96338-supp1-v1.docx
-
Supplementary file 2
List of (a) included and (b) excluded studies at the full-text screening stage with exclusion reasons.
- https://cdn.elifesciences.org/articles/96338/elife-96338-supp2-v1.docx
-
Supplementary file 3
Summary of a multi-moderator model including all moderators.
The bold typeface is used when a 95% confidence interval (CI) does not contain zero; thus, it can be interpreted as an existing significant effect in predator avoidance.
- https://cdn.elifesciences.org/articles/96338/elife-96338-supp3-v1.docx
-
Supplementary file 4
Search strings used for each database.
We accessed Scopus, ISI Web of Science core collection, Google Scholar (Japanese, Polish, Portuguese, Russian, Spanish, Simplified Chinese, and Traditional Chinese) on 08/06/2023, and Bielefeld Academic Search Engine (BASE) on 26/06/2023. BASE was used as a source of grey literature. We conducted backward and forward reference searches for key review articles using Scopus on 19/06/2023. We modified search strings to collect studies to capture studies examining the effects of eyespot patterns on birds using experimental methods. Search strings were adapted to the structure of each database.
- https://cdn.elifesciences.org/articles/96338/elife-96338-supp4-v1.docx
-
Supplementary file 5
Average maximum diameter of eyespots on Bicyclus anynana.
AM obtained the pictures from lepdata.org/photos/animals/ and https://data.nhm.ac.uk/ and measured the eyespot diameters. Raw data is available here: https://ayumi-495.github.io/eyespot/ and on GitHub (copy archived at Mizuno, 2024) and Zenodo.
- https://cdn.elifesciences.org/articles/96338/elife-96338-supp5-v1.docx
-
MDAR checklist
- https://cdn.elifesciences.org/articles/96338/elife-96338-mdarchecklist1-v1.docx
Download links
A two-part list of links to download the article, or parts of the article, in various formats.
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
A systematic review and meta-analysis of eyespot anti-predator mechanisms
eLife 13:RP96338.
https://doi.org/10.7554/eLife.96338.3
