Female oxidative status, egg antioxidant protection and eggshell pigmentation: a supplemental feeding experiment in great tits

Abstract

Oxidative stress has been suggested as a mechanism underlying the costs of reproduction and life history trade-offs. Reproductive activities may lead to high production of pro-oxidants, whose activity can generate oxidative damage when not countered by adequate antioxidant defenses. Because interindividual differences in the efficiency of the antioxidant system are influenced by an individual's diet, food availability experienced during reproduction may affect the females' antioxidant status and, in birds, their ability to transfer antioxidants into their eggs. Moreover, a female's ability to cope with oxidative stress has been suggested to influence pigment deposition in the eggshell, suggesting a possible signaling function of eggshell maculation. Here we performed a food supplementation experiment in a natural population of great tits (Parus major) in order to investigate how nutritional conditions experienced during the egg laying period affect the female's oxidative status and egg investment and how maternal oxidative status and egg antioxidant protection relate to eggshell pigmentation. We show that food-supplemented females had lower oxidative damage levels (ROMs) than non-food-supplemented females. Furthermore, a female's ROMs levels were negatively associated with the levels of yolk antioxidant protection in her eggs, but this negative association was only significant in non-food-supplemented females. This suggests that oxidative stress experienced during reproduction influences the allocation of antioxidants into the eggs. Moreover, we observed a positive relationship between eggshell pigment distribution and maternal and yolk antioxidant protection, suggesting that eggshell pigmentation is a cue of female (and offspring) quality. protection relate to eggshell pigmentation. We show that food-supplemented females 36 had lower oxidative damage levels (ROMs) than non-supplemented females. 37Furthermore, a female's ROMs levels were negatively associated with the levels of 38 yolk antioxidant protection in her eggs, but this negative association was only 39 significant in non-supplemented females. This suggests that oxidative stress 40 experienced during reproduction influences the allocation of antioxidants into the 41 eggs. Moreover, we observed a positive relationship between eggshell pigment 42 distribution and maternal and yolk antioxidant protection, suggesting that eggshell 43 pigmentation is a cue of female (and offspring) quality.

Protoporphyrin‐based eggshell pigmentation predicts hatching success and offspring sex ratio in the barn swallow

“…The SSECH has received more attention for biliverdin-based than protoporphyrin-based eggshell pigmentation: since biliverdin is an antioxidant, females could show their antioxidant capacity or their health/ body condition by depositing a larger amount of blue-green pigment on their eggs (Moreno and Osorno 2003, Soler et al 2005, Moreno et al 2006, Hargitai et al 2008; but see Krist and Grim 2007, Hanley and Doucet 2009, Honza et al 2011). Studies that have tested the SSECH on passerine species laying protoporphyrin-coloured eggs have obtained conflicting results (Martínez-de la Puente et al 2007, Sanz and García Navas 2009, Holveck et al 2012, Krištofík et al 2013, Giordano et al 2015, Hargitai et al 2016a, b, Poláček et al 2017. Indeed, contrary to biliverdin, protoporphyrin is a pro-oxidant compound and its accumulation in the liver induces oxidative stress in females (Afonso et al 1999).…”

Experimental evidence that oxidative stress influences reproductive decisions

“…) or reduced capacity to withstand the metabolic demands of offspring rearing (Fletcher et al . ; Giordano, Costantini & Tschirren ).…”

“…Work on physiological constraints of reproduction has had a prominent role in life-history research. For example, nutrient and energy limitation in females lead to reduced allocation of nutrients to their offspring (Surai 2002;Derrickson & Lowas 2007;Speakman 2008), reduced reproductive success (Koskela et al 1998;Ruffino et al 2014) or reduced capacity to withstand the metabolic demands of offspring rearing (Fletcher et al 2013;Giordano, Costantini & Tschirren 2015).…”

Effects of food limitation on the intensity of blue‐green and brown eggshell coloration: an experimental study with the canary

“…carotenoids, vitamins, polyphenols), which could be associated with reduced antioxidant capacity (Catoni et al 2008, Fletcher et al 2013, Giordano et al 2015. In addition, protein limitation can lead to increased oxidative damage and decreased antioxidant protection, probably through lower levels of uric acid and glutathione, which are important antioxidants (Li et al 2002, Feoli et al 2006, Cohen et al 2009, Swennen et al 2011, Alan and McWilliams 2013).…”