Annual variation in common eider egg size: effects of temperature, clutch size, laying date, and laying sequence

摘要: Annual variation in volumes of eggs laid by common eiders (Somateria mollissima sedentaria) nesting at La Perouse Bay, Manitoba (58°43′N, 93°27′W), was studied over 3 years (1991–1993). Temperatures during the egg-laying period were higher 1991 than 1992 and 1993. However, began 1993 same time as 1991, whereas laying approximately 2 weeks later. Eiders significantly smaller clutches other years. Egg size did not correlate with clutch or date any year. 1991. In five egg clutches, pattern intraclutch egg-size different among The last disproportionately (cold years) those Minimum daily temperatures before (during rapid yolk development) positively correlated size. this effect significant w...