Mastering Bird Anatomy
To convincingly draw birds, you must understand what lies beneath the surface. To draw feathers, you must understand how feathers grow, overlap, and insert into the body. To create the body, you must have an understanding of the bird’s skeletal structure. To pose this skeleton, you must be able to perceive the energy, intention, and life of the bird. If you understand more than can be drawn, your sketches and paintings will be informed by energy, solidity, and life.
15
SONGBIRD BILLS
Bills are birds’ essential survival tools. Study the variability of bills between species. Learn how bills attach to the head and move.
To make room for the large eye, the lower bill turns down where it meets the skull and hinges behind the eye.
When the bill is open, you cannot see its hinge, which is hidden by a stretchy membrane of skin, the rictus.
In songbirds, the eye sits on top of the bill line. To place the eye, observe its distance from the front of the head. The distance to the back may change as the bird fluffs its feathers.
Some birds show a sharp change in the angle of the cutting edge of the bill (angulated commissure). Technically, this is where the bill edge (tomium) forms a sharp angle where it meets the cheek
(rictus). Birds with angulated commissures include meadowlarks and New World blackbirds, seed-cracking finches, sparrows, grosbeaks and buntings, and many groups of nectar-feeding birds, excluding hummingbirds.
The shape of the open bill is formed by the inner edge of the bill and the skin that stretches across the cheek. You may be able to see both in the angles of the open bill.
Upper mandible. Note small nostril (sometimes covered by feathers) and change in angle where the edge of the bill turns down. Feathers of the head curve into the bill from behind.
Lower mandible feathers curve into the base of the bill and extend out underneath the bill.
16 Laws Guide to Drawing Birds
CRANIAL KINESIS
Most bill movement comes from dropping the lower bill. The upper bill can also move independently of the rest of the skull (kinesis), but this movement is usually subtle.
Movement of the upper bill may be subtle. In one study, White-throated Sparrow kinesis was measured using high-speed photography and showed a barely detectable 9.5 degrees of movement in full song. Some birds may show as much as 12 degrees of movement.
Narrow-billed songbirds such as warblers and wrens may show observable movement of the upper mandible. It will be subtle, so be cautious and avoid overdoing it. When birds hold their heads up when they sing, the upper bill appears to flip up more than it actually does.
It may be hard to detect movement of the upper bill.
Oops… the bill should not hinge at the front of the head.
Woodcocks and long-billed shorebirds can move the tip of the upper bill to grasp worms under the mud.
Yawning birds or begging chicks may raise the upper bill more noticeably.
The upper bill should not flip up this much when the bird sings.
Parrots have the greatest upper bill flexibility of all birds. The movement of the bill helps them manipulate nuts and seeds. This movement occurs at a hinge between the skull and the bill (prokinesis).
Less common is the ability to move the upper bill from a hinge point within the bill itself (rhynchokinesis).
Mastering Bird Anatomy 17
FEATHER GROUPS VS. MARKINGS
Feather groups are present in all birds and contribute to the bird’s shape. Markings are formed by colored feathers within these groups.
Auriculars Stiff feathers that cover the ear and form a triangular patch that extends back from the corner of the opening of the bill and the middle of the eye.
Orbital feathers Tight feathers above and below the eye. Two to four rows of feathers may be seen below the eye. Even without special coloring, you can see the texture of this feather group.
Lores Rows of small feathers in front of the eye
Supraloral feathers arch over the lores at the front of the eyebrow.
Feather
Groups
Median crown-stripe
Lateral crown-stripes Supercilium or eyebrow
Eye-stripe along the upper edge of the auriculars
Nape feathers cover the back of the neck behind the auriculars.
Feather Markings
Throat
Eye-ring and broken eye-ring made by contrasting orbital feathers
Malar A zone of feathers that starts at the curve at the base of the lower bill and covers the bones of the mandible. A small crease is often visible at the bottom edge of the bill, indicating the lower edge of the malar. The distinction between the malar and the throat becomes less clear as you move away from the bill.
Subauricular stripe or mustachial stripe along the lower edge of the auriculars
Lateral throat-stripes
Markings can be made by the coloring of entire feather groups.
Other markings are made by dark feathers along the edges of feather groups.
Some markings are made by a combination of the colors of feather groups and the colors at the edges of groups.
18 Laws Guide to Drawing Birds
STEP BY STEP: DRAWING HEAD DETAILS
Before drawing head markings, lightly outline the feather groups. These give structure to the face and help you place the markings correctly.
Start by drawing the eye-ring as a zone of tightly packed feathers that circle the eye. You may find it split into two sections, one above and one below the eye. There may be additional rows below the eye.
A small crease drops from the bottom corner of the bill. It will be more clearly defined closer to the bill. The malar region sits between this crease and the ear patch.
The supercilium is the stripe above the eye. The front edge of this stripe makes an arc over the lores called the supraloral region.
Birds’ necks are flexible, so the nape feathers that cover the neck will take on a variety of shapes depending on the position of the bird’s head. There may be a change in the angle of the head profile where the nape connects to the back of the head. Note that this sparrow’s eyeline is raised because the nape and crest feathers are lofted.
Draw the ear patch as a triangle of feathers that starts behind the eye. The front edge begins at the rear corner of the bill. This edge may change angle below the rings of feathers that surround the eye. The feathers in front of the eye puff up and out to form the lores.
When a bird lifts its nape feathers, the contour of the head, the shape of the feather groups, and the head markings change dramatically. Note how the rear edge of the auriculars and the supercilium broaden and point up.
Mastering Bird Anatomy 19
TURNING HEADS
Crosshairs through the bill and eye and around the head will help you keep track of the alignment of the bill, eye, and feather groups as a bird moves its head.
Visualize and draw the eye-bill line as a circle that wraps all the way around the head. Draw a second circle through the middle of the face and around the back of the head.
The eye sits on top of the eye-bill line.
The base of the bill fits over the intersection of the crosshairs.
The tip of the bill is aligned with the intersection of the crosshairs.
A line through the intersection of these two circles aligns the bill. Bill length will appear to change with head position. In a side view, you will see the full length of the bill. It appears shorter in 3/4 views.
The symmetry of lines on the head is maintained by keeping track of the center line and the eye-bill line. As the head turns, think of these lines as circles that wrap around the head. Align facial stripes and markings relative to these lines. Pay particular attention to the shapes made by patterns that wrap around the far side of the head. It will help to look at these as negative shapes. Also note that the shape of the eye will be foreshortened. At what point can you no longer see the eye on the far side of the head?
20 Laws Guide to Drawing Birds
HEAD ANGLES
Bird heads bulge outwards below the eye. Look for this change in angle in front and in 3/4 views. This bulge is more pronounced in some birds, such as the flycatcher genus Myiarchus and Vermilion Flycatchers.
In profile the back of the bird’s head is rounded. There may be a change in angle at the nape.
In a 3/4 view you can see a hint of the change in the angle below the eye on the far side. The back of the head is more rounded. At this angle the round eye becomes an ellipse.
In the front view, note the change in the slope of the silhouette of the head below the eye. The angle is even more pronounced when the head is retracted.
Lateral crown bulge
Change in angle below eye
Lateral crown bulge
From the side, the head is rounded.
In a 3/4 view you see both the rounded back and an angular side of the head.
From the front, the head is angular, resembling the command module of a rocket.
Mastering Bird Anatomy 21
BODY FEATHERS
One key to drawing feathers is to understand more of the anatomy than can be drawn. Study feather placement and groups to inform your rendering of the plumage.
Feathers overlap like roof shingles, shedding wind and water. The feathers also emerge in groups. Within each group, they make geometric rows that point in a similar direction, increasing in size from front to back. Studying feather groups will give you a mental map of feather direction and placement. While this is a tremendously useful exercise, avoid rendering every feather that you know should be there or your birds will look like pinecones or lizards.
The boundaries between feather groups are often marked by subtle creases or shadows. Feather gr...