Dodo Birdesque - Humped Rump, tail down.

[Velder]

Any ideas as to why this cockerel has this humped rump with tail down?
It may have always been like this as it was noticed very soon, weeks or sooner – hard to notice with days-old baby chicks.

Purchased from McMurrayhatchery, originally suspected disease or something, possible deformation?

The first two photos which exclude the head are at ~16.5 weeks old currently, the last four photos are at different ages.

Thank You.

 

[Wyorp Rock]

It may have always been like this as it was noticed very soon, weeks or sooner – hard to notice with days-old baby chicks.

Since it seems noticeable at a young age, likely a genetic or developmental problem.

I would not use him for breeding.

 

[dawg53]

It's called "Roachback," a spinal deformity that's genetic.