More excellent birds !
No I don't think it is the scale of the background bird that throws it forward , perhaps more that it is isolated on the white paper.
Maybe a little more generalised suggestion of grass might stop the eye been led to it too ?
Using the two devices to deepen the perspective might have been too much used together ?
Although I do very much like the use of the S curve to lead the eye through the drawing.
It's funny isn't it, all this intellectual analysis after the event - in which when in the process of making it NO or very little analysis was involved
Still it can help the next one on occasion