Sexual size dimorphism in lizards: Rensch's rule, reproductive mode, clutch size, and line fitting method effects

Tao Liang, Shai Meiri*, Lei Shi*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


Rensch's rule relates to a pattern whereby sexual size dimorphism is more female-biased in small-sized species and more male-biased in large-sized ones. We collected literature and museum data on the body size of males and females belonging to 4032 lizard species, as well as data on their reproductive modes and clutch sizes. We used phylogenetic comparative analyses, and general linear mixed models, to test Rensch's rule and examined how reproductive mode and clutch size affect sexual size dimorphism. Sexual size dimorphism was independent of clutch size in lizard species with variable clutch sizes and in oviparous lizards. Large litters were associated with female-biased sexual dimorphism in viviparous and in scincomorph lizards. Inference regarding Rensch's rule depended on the analytical method used to identify it. The widely used, but less conservative, reduced major axis regression usually support Rensch's rule while ordinary least squares regressions mostly show isometric relationships. The rule tended to apply more to oviparous than to viviparous lizards. We infer that Rensch's rule is, at best, a weak pattern in lizards. This is especially true in viviparous lineages where females reproduce infrequently and therefore evolve large sizes to maximise fecundity, resulting in female-biased dimorphism.

Original languageEnglish
Pages (from-to)787-803
Number of pages17
JournalIntegrative Zoology
Issue number5
StatePublished - Sep 2022


FundersFunder number
National Natural Science Foundation of China31660613


    • fecundity selection
    • reduced major axis regression
    • sexual selection
    • sexual size dimorphism
    • viviparity


    Dive into the research topics of 'Sexual size dimorphism in lizards: Rensch's rule, reproductive mode, clutch size, and line fitting method effects'. Together they form a unique fingerprint.

    Cite this