We reconstructed the nutrient source for egg synthesis by sampling Black-headed Gull (Larus ridibundus) eggs for yolk, analyzing their carbon stable isotope ratio, and comparing that to hatchling down. Most of the variation in carbon stable isotope ratio was explained by differences between nests, the within-nest variation being explained by laying order. These data indicate significant differences in diet choice between individual females and changes in food choice or body-store dynamics during egg laying. Among-egg variation in the carbon stable isotope ratios of the yolk were closely reflected in the hatchling down, on average down being enriched by 3.1‰ d13C relative to yolk. Our findings support the contention that pre-laying female diets can be evaluated from hatchling down. Relación entre la tasa de isótopos estables de carbono en el plumón y la yema del huevo en Larus ridibundus [KEYWORDS: carbon stable isotope ratios ; egg production ; Larus ridibundus.]
Original languageEnglish
JournalJournal of Field Ornithology
Journal publication date2004

ID: 88647