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Insulin‐like growth factor 1 and growth rate in nestlings of a wild passerine bird
Author(s) -
Lodjak Jaanis,
Mägi Marko,
Tilgar Vallo
Publication year - 2014
Publication title -
functional ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.272
H-Index - 154
eISSN - 1365-2435
pISSN - 0269-8463
DOI - 10.1111/1365-2435.12164
Subject(s) - biology , passerine , fledge , growth rate , brood , insulin like growth factor , altricial , compensatory growth (organ) , zoology , reproduction , ecology , hatching , growth factor , endocrinology , biochemistry , geometry , mathematics , receptor , kidney
SummaryPost‐natal growth rate is an important life‐history trait that is strongly associated with survival during the transition to independence and the overwinter period. In laboratory conditions, insulin‐like growth factor 1 ( IGF ‐1) has been shown to be one of the main hormones regulating growth and development in maturing vertebrates. However, the extent to which plasma IGF ‐1 enhances growth in free‐living animals, particularly in birds, is still unclear. In this study, we used brood size manipulation in free‐living great tits ( P arus major ) to investigate how changes in nestling nutritional condition and post‐natal growth rate are related to nestling IGF ‐1 levels. Nestlings in reduced broods had increased post‐natal growth rate, better body condition and also higher IGF ‐1 levels prior to fledging than those in control and enlarged broods. Plasma IGF ‐1 levels were higher in the middle of the nestling period, when growth rate is most rapid, than in the pre‐fledging stage. Our results suggest that nestling plasma IGF ‐1 varies depending upon resource (e.g. food) availability and potentially plays an important role in regulating the post‐natal growth and development of wild passerines in a time‐specific manner.