Gender Guess- 3 week light sussex has me stumped

[LaFleche]

I’m starting to think maybe one of her Roos jumped into another pen

This, or not waiting long enough to collect the fertile eggs after separating the breeds into their respective breeding pens.

Who knows...

 

[PimsGarden]

I'm no expert by any means, but after looking at a lot of birds this year trying to get better at sexing I would lean towards pullet. But you know how it goes sometimes, late development and whatnot could change things. In my personal chicks I've noticed a behaviour difference as well, my cockerel seems to be more of a loner sometimes but will pair up with any of the pullets during the day whereas the pullets only pair up with him and one other pullet of preference. Maybe that's just my flock dynamic tho, he is at the top of the pecking order too.

Again I'm no expert by any means, but I'm feeling a pullet here! Regardless it's a pretty bird already and id be super happy with it, congrats!

 

[NatJ]

It came from a reputable breeder who we’ve bought from before. I don’t think she breeds Delaware. I’m starting to think maybe one of her Roos jumped into another pen

I agree, that would make sense.

I'm pretty sure it is barred silver columbian (like Delawares), but that same combination of traits can come from various mixes as well.