“…While the egg is being formed in the reproductive tract of female birds, theca and granulosa cells that surround the oocyte produce hormones that end up in different layers of egg yolk (Gil, 2003). Maternal yolk hormone deposits during egg formation are influenced by a variety of environmental conditions; including their physical environment (Schwabl, 1996;Guesdon et al, 2011;Guibert et al, 2010), sexual and social context (Gil, 2008), social status (Tanvez, Parisot, Chastel, & Leboucher, 2008), body condition (Verboven et al, 2003), age (Okuliarova, Skrobanek, & Zeman, 2009), and laying order in a clutch (Gil, 2008).…”