Experimental manipulation of maternal corticosterone: Hormone transfer to the yolk in the zebra finch Taeniopygia guttata

•We quantified a temporal window for avian maternal corticosterone yolk deposition.•Oral dosing at ovulation elevated both maternal plasma and egg yolk corticosterone.•Elevated maternal corticosterone did not affect maternal reproductive outputs.•Yolk corticosterone concentrations did not differ with egg order or yolk layers.•Maternal corticosterone variations at ovulation may impact offspring development.