Translator Disclaimer
22 March 2022 Characterization of iris dichromatism in Sri Lanka Bush Warbler (Elaphrornis palliseri)
Tharindu Krishan, Sampath S. Seneviratne
Author Affiliations +

Sexual dimorphism may appear in various forms such as anatomical, plumage, or vocal features. Production of such variation can be costly. However, sexual dimorphism may provide long-term fitness benefits. The Sri Lanka Bush Warbler (Elaphrornis palliseri) is a sexually monomorphic and monotypic passerine endemic to the montane cloud forests of the island of Sri Lanka. The iris of this bird shows a marked variation and individuals have either red or ivory-cream colored irises. We studied the iris dichromatism of Sri Lanka Bush Warbler with respect to morphometric and sexual differences. We used PCR-based molecular sexing (n = 8 individuals) and multivariate statistics to analyze morphometric data (n = 20). We found that the iris dichromatism of Sri Lanka Bush Warbler is sex-specific: all females examined (n = 6) had ivory-cream irises and both males examined had bright-red irises, whereas none of the phenotypic traits examined were sexually dimorphic. Our results suggest that the sexual dichromatism observed in this dense understory–dwelling, cloud forest bird might play a central role as a short-distanced optical signal.

Tharindu Krishan and Sampath S. Seneviratne "Characterization of iris dichromatism in Sri Lanka Bush Warbler (Elaphrornis palliseri)," The Wilson Journal of Ornithology 133(3), 504-509, (22 March 2022).
Received: 17 November 2020; Accepted: 1 October 2021; Published: 22 March 2022

genetic sexing
mate recognition
phenotypic variation
sexual dimorphism
Get copyright permission
Back to Top