Date Published: February 20, 2018
Publisher: Public Library of Science
Author(s): Erick González-Medina, José Alfredo Castillo-Guerrero, Sharon Zinah Herzka, Guillermo Fernández, Antoni Margalida.
Understanding the role of diet in the physiological condition of adults during reproduction and hence its effect on reproductive performance is fundamental to understand reproductive strategies in long-lived animals. In birds, little is known about the influence of the quality of food consumed at the beginning of the reproductive period and its short-term effects on reproductive performance. To assess the role of diet in the physiological condition of female blue-footed booby, Sula nebouxii (BFBO), during reproduction we evaluated whether individual differences in diet (assessed by using δ13C and δ15N values of whole blood from female birds and muscle tissue of the principal prey species) prior to egg laying and during incubation influenced their lipid metabolic profile (measured as triglyceride levels and C:N ratio) and their reproductive performance (defined by laying date, clutch size and hatching success). Females with higher δ15N values in their blood during the courtship and incubation periods had a higher lipid metabolic profile, earlier laying date, greater clutch size (2–3 eggs) and higher hatching success. Females that laid earlier and more eggs (2–3 eggs) consumed more Pacific anchoveta (Cetengraulis mysticetus) and Pacific thread herring (Opisthonema libertate) than did other females. These two prey species also had high amounts of lipids (C:N ratio) and caloric content (Kcal/g fresh weight). The quality of food consumed by females at the beginning of reproduction affected their physiological condition, as well as their short-term reproductive performance. Our work emphasizes the importance of determining the influence of food quality during reproduction to understand the reproductive decisions and consequences in long-lived animals.
Food availability and selection has a substantial effect on energetic and fitness costs and performance during reproduction and therefore influences how individuals adjust their reproductive strategies [1,2,3]. Thus, it is not surprising that the nutritional quality of the available food influences the reproductive success and decisions in natural populations of many animals [4,5,6]. Despite extensive studies regarding the effect of food availability on maternal reproductive traits for specific taxa [5,6,7,8,9], the manner in which female reproduction responds to food availability and quality might differ among species and deserves further investigation .
Higher δ15N values in the blood of females during courtship and incubation were related to higher lipid metabolic profile (based on triglyceride levels and C:N ratio), earlier laying date, greater clutch size (2–3 eggs) and higher hatching success. Hence, the quality of the diet consumed by females of BFBO during the early stages of reproduction had short-term consequences for their physiological condition and reproductive performance.