The body of a resting heron is confusing to understand anatomically. Instead of a head, neck, shoulder, wings, and chest, see the body parts as abstract shapes to copy and assemble. Focus on the unique shape of each of the parts.
Observe the posture, proportions, and angles of the head and body mass. Draw light lines to block in the relative size of the head and body. Once your guide lines are in place, fill in the body by breaking it down into interlocking geometric shapes. Your accuracy in observing the proportions and angles of each of these shapes will determine the accuracy of the drawing. If you just say “the neck bulges in the front,” your brain will take the easy path and you will draw a bulge below the head without really looking. However if you observe and describe the detail, you will say “from a point just under the base of the bill the neck angles out slightly, then drops straight down, then sharply in to a point, curving up to just above the shoulder, then turns up to the base of the beak,” and thereby capture the nuances of the shape. Assembling a drawing, one piece at a time, is my go to approach whenever I am confused by the anatomy of structure of what I am seeing.
This approach is even more powerful when combined with an anatomical understanding of the subject. If you know where the neck bends and connects, you will be better able to pick out and place the important angles that define the underlying structure.