How long hen fertile for?

[becky_animals]

Odd question - I have 5 young mixed bantams (farm store purchase), one obviously a rooster and 4 probably hens. I separated the rooster from the others in early September, before the hens started laying, as the rooster was pestering the hens endlessly. About a week ago two of the hens started laying, and I sure thought the white spot on the eggs looked like they were fertilized - concentric circles looking. So I assumed one of the two that weren't yet laying was a rooster, just one who'd never crowed or been seen pestering the hens.
But yesterday I found 4 eggs (and I'm sure they weren't missed from the day before) and they all looked fertilized. Is it possible that the separated rooster's sperm survived in the hens for 4 weeks before they started laying? Or am I misinterpreting the fertilizable spot on the eggs?
Thanks!

 

[oldhenlikesdogs]

Pictures of your birds, and eggs may help. I thought sperm life was a couple of weeks max, but I'm not positive. Are you sure all are females? Are you seeing the circle around the germinal disk?

 

[aart]

Sperm can be held and used for up to about 4 weeks.

 

[U_Stormcrow]

@aart 's experience is consistent with what I've read in dozens of posts here (mostly by BYC participants with mixed flocks of pure birds), and found on the more reliable Chicken oriented web sites and publications.

See for instance this (somewhat cagey) blog post at Cackle Hatchery Chicken Sperm Storage as one example of many, many. .and if you prefer Science, start Here


You can chisel his answer in stone.

 

[becky_animals]

Here're photos.
I'd thought birds could only store sperm for a few days, but all the posts saying a month or so make sense - the known rooster's only been away from the hens for 3 or 4 weeks, and they've only been laying eggs part of that time.
Thanks!