sibling size difference

[LadiesAndJane]

I have two gorgeous 9 week old birchen marans pullets, one black and one blue. Have had them since they were eggs, and they come from the same breeder. They are either full siblings or half siblings. Both appear healthy, both appear to be eating well. My concern is the blue is about 1/2 again as big as her smaller black sister and definitely has a lot more heft to her. Is it just genetic variation or should I be concerned? They were the same size until a few weeks ago. I did have to assist the black pullet when she was a chick during hatch, but did not seem to be any other health issues with her even then.
Thanks!

 

[Northwest_Wannabe]

Do you have a picture?

 

[LadiesAndJane]

Do you have a picture?

Got my daughter to run out and get photos, these were taken just now! Thanks!

 

[Northwest_Wannabe]

Hmm I was thinking possibly a smaller could be a rooster but I'd probably just chalk this up to genes! Perhaps the blue had a bigger dad/mom/etc? Maybe the black was a little slower since they needed help, but they both appear to be healthy enough at least in photos! That first photo is super adorable <3

 

[aart]

Probably just genetic variances.
But if smaller bird had trouble hatching, it may not have developed optimally.

 

[LadiesAndJane]

Hmm I was thinking possibly a smaller could be a rooster but I'd probably just chalk this up to genes! Perhaps the blue had a bigger dad/mom/etc? Maybe the black was a little slower since they needed help, but they both appear to be healthy enough at least in photos! That first photo is super adorable <3

Thanks for your reply. I am not going to worry then. They seem happy and healthy! They also hang out together, which is sweet, and are nice to their silkie hatch/brood/coop mates. My 12 year old has a good eye, when I can get her to cooperate!

 

[LadiesAndJane]

Probably just genetic variances.
But if smaller bird had trouble hatching, it may not have developed optimally.

Thanks! I appreciate your reply. 3 of the marans needed hatching assistance, the other 2 that did I sold, so not sure if they have the same size issue or maybe the blue is just big for her age!

 

[Mrs. K]

I too thought it was a rooster/pullet, but not from your pictures. More than likely genes, but do you have just a single feed bowl? Might put an extra feed bowl out, where as when the birds are eating at one bowl, can't be seen from another. Especially if you have this pair with other older birds.

Mrs K

 

[LadiesAndJane]

I too thought it was a rooster/pullet, but not from your pictures. More than likely genes, but do you have just a single feed bowl? Might put an extra feed bowl out, where as when the birds are eating at one bowl, can't be seen from another. Especially if you have this pair with other older birds.

Mrs K

Thanks they are actually among the oldest of our chickens believe it or not! We also have two ameraucana pullets that are 2 weeks older that definitely are the bossiest. There are 10 birds all together in this area, the rest of them being silkies. There are three large food stations so I believe everybody gets food! I do appreciate your reply and thoughtfulness, thank you!
Photo of them dust bathing, they do everything together!