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Data and code for Caves, Dixit, Colebrook-Robjent, Hamusikili, Stevens, Thorogood, and Spottiswoode: Hosts elevate either within-clutch consistency or between-clutch distinctiveness of egg phenotypes in defence against brood parasites

Citation

Caves, Eleanor et al. (2021), Data and code for Caves, Dixit, Colebrook-Robjent, Hamusikili, Stevens, Thorogood, and Spottiswoode: Hosts elevate either within-clutch consistency or between-clutch distinctiveness of egg phenotypes in defence against brood parasites, Dryad, Dataset, https://doi.org/10.5061/dryad.02v6wwq34

Abstract

In host-parasite arms races, hosts can evolve signatures of identity to enhance detection of parasite mimics. In theory, signatures are most effective when within-individual variation is low (“consistency”), and between-individual variation is high (“distinctiveness”). However, empirical support for positive covariation in signature consistency and distinctiveness across species is mixed. Here we attempt to resolve this puzzle by partitioning distinctiveness according to how it is achieved: (1) greater variation within each trait, contributing to elevated “absolute distinctiveness” or (2) combining phenotypic traits in unpredictable combinations (“combinatorial distinctiveness”). We tested how consistency covaries with each type of distinctiveness by measuring variation in egg colour and pattern in two African bird families (Cisticolidae and Ploceidae) that experience mimetic brood parasitism. Contrary to predictions, parasitised species, but not unparasitised species, exhibited a negative relationship between consistency and combinatorial distinctiveness. Moreover, regardless of parasitism status, consistency was negatively correlated with absolute distinctiveness across species. Together, these results suggest that (i) selection from parasites acts on how traits combine rather than absolute variation in traits, (ii) consistency and distinctiveness are alternative rather than complementary elements of signatures, and (iii) mechanistic constraints may explain the negative relationship between consistency and absolute distinctiveness across species.

Methods

Please see associated Readme file.

Usage Notes

Please see associated Readme file.

Funding

Pomona College-Downing College Student Exchange Scholarship

Natural Environment Research Council, Award: NE/K00929X/1

Biotechnology and Biological Sciences Research Council, Award: BB/G022887/1

Royal Society Dorothy Hodgkin Fellowship

Biotechnology and Biological Sciences Research Council, Award: BB/J014109/1

Pomona College-Downing College Student Exchange Scholarship

Royal Society Dorothy Hodgkin Fellowship