Butchered Quail - Dark areas found....what is it?

[Scot1458]

Noticed this is some females I butchered recently, the entire end of the bird is black. There is no odor, or abnormal activity in the birds themselves. They have been in breeding cages, so I am thinking (hoping) it's due to the cold or brusing from the male. There is a sand box in there, so maybe frostbite from when they sit?

anybody hever seen anything like this?

 

[JJMR794]

That is bruising.

 

[Scot1458]

thanks!!!