Could be all sorts of reasons for the size difference, but not likely to be male/female at this age, they are really too young - end of next week we might be able to see a gender size difference but not now at a week old (for the oldest). Could be first and last to hatch, could be that that one chick is just smaller than the other (think of Mistral), could be the first chick is/was/has always been bigger. No way to tell for sure. We made the assumptions based on a couple of points - 1) is size between all the chicks visible, 2) the level of development - think coordination - remember it doesn't take long for the chicks to become quite stable when begging for food, so was there much of a difference in that stability between the two chicks and 3) knowing that newly hatched chicks are the most vulnerable in the group and the first was hatching & did hatch during the June 2nd storm and the second was eating fine for a couple of days and then we had more rain. The older chicks were 3/4 days vs essentiall a day and a bit for the last chick.
Ultimately, it doesn't really matter, we lost two chicks due to the weather and we have two chicks that survived despite the weather. We aren't never going to know all the contributing factors - rain, cold, age, Hurricane's & Brooklyn's size (not big), nesting experience, more food (less cover), less food (more cover), underlying weaknesses in the chicks. All could have contributed or it could all have been due to a single cause.
Sorry folks, no real answers for you. Will be interesting to see who they develop and what their genders are at banding though ...
