Organizing effects of adverse early-life condition on body mass, compensatory growth and reproduction: Experimental studies in rock pigeons

Early-life food conditions can have profound impact on adult behavioural performance. In song birds, early-life food conditions affect adult physiology and cognitive performance such as song learning and spatial learning. However, effects on reproductive behaviour other than song, such as visual courtship display, pair formation, and egg laying, which are all important determinants of fitness, received hardly any attention. In this study, rock pigeons Columba livia were raised either in a food ad-libitum or at impoverished (quality) and restricted (quantity) food conditions, in which the latter was applied for either 26 or 8 d after hatching and in slightly different severity. Their growth and reproductive behaviour in adulthood was analysed under semi-natural conditions. Impoverished and restricted food (IRF) negatively affected adult body mass, pair-bonding behaviour, courtship (males) and being courted (females), and induced incomplete compensatory growth. Further analyses suggest that the effects of IRF on behaviour could result from the strong effects on body mass, and perhaps also from detrimental effects of compensatory growth. These results provide evidence that adverse early-life condition can negatively impact on reproductive success, as suggested by the significant effect on egg production, which will very likely lead to a lower life-time fitness. The detrimental effects on male courtship indicate that IRF can affect sexual displays via other pathways than by impaired cognition as has been suggested for bird song, since courtship in the pigeons is not learned.