Sidespecific effect of yolk testosterone elevatio

Authors: Gergely Nagy György Blázi Gergely Hegyi János Török

Publish Date: 2016/01/05

Volume: 103, Issue: 1-2, Pages: 4-

PDF Link

Abstract

Secondtofourth digit ratio is a widely investigated sexually dimorphic morphological trait in human studies and could reliably indicate the prenatal steroid environment Conducting manipulative experiments to test this hypothesis comes up against ethical limits in humans However oviparous tetrapods may be excellent models to experimentally investigate the effects of prenatal steroids on offspring secondtofourth digit ratio In this field study we injected collared flycatcher Ficedula albicollis eggs with physiological doses of testosterone Fledglings from eggs with elevated yolk testosterone regardless of their sex had longer second digits on their left feet than controls while the fourth digit did not differ between groups Therefore secondtofourth digit ratio was higher in the testosteroneinjected group but only on the left foot This is the first study which shows experimentally that early testosterone exposure can affect secondtofourth digit ratio in a wild population of a passerine birdWe are grateful to members of the Behavioural Ecology Group for their help during fieldwork The study was conducted under licences from the Middle Danube Valley Inspectorate for Environmental Protection Nature Conservation and Water Management permission no 2573/2/2004 This study was supported by the Hungarian Scientific Research Fund OTKA grant nos T049650 and K75618 the Eötvös Loránd University the Hungarian State PhD Scholarship to GN the Erdők a Közjóért Alapítvány and the Pilis Park Forestry

Keywords: