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. 2019 Feb;65(1):83-88.
doi: 10.1093/cz/zoy053. Epub 2018 Jul 7.

Synchronous waving in fiddler crabs: a review

Patricia Ruth Yvonne Backwell  1
Affiliations

Synchronous waving in fiddler crabs: a review

Patricia Ruth Yvonne Backwell. Curr Zool. 2019 Feb.

Abstract

Many animals that use acoustic communication synchronize their mate attraction signals: individuals precisely time their calls to overlap those of their neighbors. In contrast, synchrony in the mate attraction displays of species with visual/motion-based signals is rare. It has only been documented in five species of fiddler crabs. In all of them, small groups of males wave their single large claw in close synchrony. Here, I review what we know about synchrony in fiddler crabs, comparing the five species with each other to determine whether similar mechanisms and functions are common to all. I also propose future research questions that, if answered, would shed light on synchronous behavior in both visual and acoustic signallers.

Keywords: fiddler crab; mate choice; synchrony; visual signal; wave timing; waving.

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Figures

Figure 1.
Figure 1.
Photograph of Austruca mjoebergi males waving in synchrony.
Figure 2.
Figure 2.
The mean phase angles (α) for synchronous groups of males when females were present (top row) and when females were absent (bottom row) in four species of fiddler crabs. An α of 0° or 360° represents precise synchrony; an α of 180° represents complete alternation. The average phase angle and the average length of the mean vector (for all synchronous groups combined) is given below the species name. Vector length is a measure of data clumping around the mean α: a vector length of 0 is uniformly distributed; a vector of 1 is tightly clumped. The vector length data for Austruca occidentalis is not presented because it is currently stored on “floppy disks”.
Figure 3.
Figure 3.
A cluster of males around a female (black). The males that fall within the cone of selective attention of male # 1 (males 2, 3, 4, and 5) would be the neighbors that trigger his synchronous waving. Males that fall outside of his field of selective attention (males 6, 7, and 8) would not trigger synchrony.
Figure 4.
Figure 4.
Relationship between the seven genera of fiddler crabs (left) with the two genera that contain synchronously waving species marked in grey. The relationship between the Austruca lactea complex (right): species with synchronous waving are marked with an asterisk. Based on Shih et al. (2016).
See this image and copyright information in PMC

References

    1. Araujo SBL, Rorato AC, Perez DM, Pie MR, 2013. A spatially explicit model of synchrony in fiddler crab waving displays. PLoS One 8:e57362.. - PMC - PubMed
    1. Backwell PRY, Jennions MD, 2004. Coalition among male fiddler crabs. Nature 430:417. - PubMed
    1. Backwell PRY, Passmore NI, 1996. Time constraints and multiple choice criteria in the sampling behaviour and mate choice of the fiddler crab, Uca annulipes. Behav Ecol Sociobiol 38:407–416.
    1. Backwell PRY, Jennions MD, Passmore NI, Christy JH, 1998. Synchronised courtship in a fiddler crab. Nature 391:31e32.
    1. Backwell PRY, Jennions MD, Christy JH, Passmore NI, 1999. Female choice in the synchronously waving fiddler crab Uca annulipes. Ethology 105:415–421.