Measuring Tail Angle

[ejcrist]

I'm a bit lost when it comes to measuring tail angles. The SOP has an illustration showing and angular measurement between the first sickle feather relative to the back, which in the case of the illustration is horizontal. So do you measure the angle between the first sickle feather or the center line of the tail? Also, in the case of birds with a continually sloping back, like Dominiques, at what point in the back do you choose to do the measurement?

Also what does it mean when a bird has a break in the tail?

 

[pinewoodacres]

I have the same question. I was originally thinking the angle was in relation to the ground but I also read it’s in relation to the back.

 

[nicalandia]

 

[pinewoodacres]

View attachment 3011332

Cool chart, thanks. So is this in comparison to the bird’s back or the ground?

 

[nicalandia]

Cool chart, thanks. So is this in comparison to the bird’s back or the ground?

Yes

 

[pinewoodacres]

Yes

Which one? The bird’s back is arguably not parallel with the ground.