Morphology of Birds- Essential for birdwatching

           What is Morphology

    Morphology is a branch  dealing with the study of the form and structure of organisms and their specific structural features. It has two parts. One is study  of the outer appearance (shape, structure, color, pattern, size) and it is called external morphology (or eidonomy). Another one is study of  the internal parts like bones and organs, It is called. internal morphology (or anatomy). In this article only external morphology will be discussed.

                Why study of bird morphology is essential

     Colors and shapes  varies in birds from species to species.  But at the same time it is fact that the arrangement of feathers  is remarkably similar across all species. When trying to identify a bird by its appearance, to have some knowledge about  group feathers and a bird’s body parts is  the most important  for the birders. 

    Knowledge about  a  bird’s morphology such as feathers and body parts will enable you to not only write a good description when you see a bird but also, will enable you to understand someone else’s written descriptions of a bird others see. Lets take an example of Red Vented Bulbul. If you don't know what the Vent is, then you can not understand why it is called Red Vented. On the other hand, if you don't have knowledge about the name of different parts of a bird, you will not be able to take notes about the physical appearance when you see an unknown bird in your field book.

       Different parts of Head

     Bird's head varies according to species. But construction are overall same. Different parts of head has different name.

Orbital Ring: Unfeathered ring or skin around the eye. Some birds have brightly color Orbital Rings while others do not have one at all. Orbital ring can change color over time.

Iris: Refers to the colored part of the eye surrounding the pupil, which is always black. In some birds the iris color change with age.

Nostril: Equivalent to a channel of the nose of a bird. 

Nail: Tip of upper mandible. In ducks the size and coloration of the nail can be an important identification feature.

Gape: Fleshy edges at corners or the base of the beak. In most birds the gape are obvious in young individuals.

Nape: Refers to the area behind the neck.

Supraorbital Ridge: Is the boney protuberance above the eye socket; this ridge helps shade and protect the eye and gives raptors their fierce look.

Cere: Is the bare area surrounding the nostrils and can be different colos according to species, age and sex of the bird.

Chin: Is a very small area at the base of the lower mandible and can often be a good clue for the identification of certain birds.

Culmen: Refer to the ridge along the top of the upper mandible.

Crown: Refers to the top area of the head.

Forehead: Area between the bill and the crown.

Post Ocular Spot: Feathered or skin spot found behind the eye .

Post Ocular Stripe: Stripe of feathers that project from the eye down bordering the throat or gorget. 

Bill: The size, shape and color of a bird’s bill known as beak also  is a way of  identification.  It has two parts one is Upper mandible and lower mandible. Different birds have  different types of bill e.g  curvature in the bill,  unique markings, colors  or bands.

             Different parts of body

Throat: A bird’s throat may be a different color from its surrounding plumage, or it may be marked with spots, streaks or lines. Malar stripes may frame the throat as well, helping set it off from the rest of a bird’s body. For many birds, the chin and throat have similar colors and markings.

Neck: The neck of a bird is hard to see on many species, since it can be relatively short and insignificant. On wading birds, however, the neck is much more prominent and can be a good place to look for field marks. The length of the neck can also help distinguish different bird species.

Back: A bird’s back is often broad and easy to see in the right posture. Look for different colors and markings along the back that distinguish it from the neck, rump and wings.

Chest: The chest (also called the breast) is the upright part of the bird’s body between the throat and the abdomen. A bird’s chest may be differently colored or marked with stripes, streaks or spots that can help with identification.

Abdomen: The abdomen or belly of a bird extends from the bottom of the chest to the undertail coverts. The colors and markings on the abdomen may vary from the chest and flanks, making it a good feature to check for identification.

Flanks: The flanks (sides) of a bird are located between the underside of the wings and the abdomen. In many bird species, the flanks have unique colors or markings, though depending on how the birds carry their wings, the flanks may be difficult to see.

Wings: Birds’ wings are their upper limbs used for flight. Wing bars or patches are useful field marks. Structure of wing has been described bellow.

Rump: A bird’s rump is the patch above the tail and low on the back. For many birds, the rump does not stand out, but some species show unique rump color patches that are useful for identification.

Tail: The length, shape and colors of a bird’s tail are important for proper identification. The tail can be held in different positions when the bird is perched or flying, however, and watching for different markings can help distinguish different birds.

Undertail Coverts: The short feathers beneath the tail are the undertail coverts, and these feathers often show unique colors or markings that can distinguish bird species.

Legs: Birds’ legs vary in length and color, both of which can be useful field marks for proper identification. The thickness of the leg, while difficult to see on many species, can also be a clue, as can any feathering. Some raptors, for example, have heavily feathered legs that can be used to identify the birds.

Feet: Many birds’ feet are the same color as their legs, but not always. The orientation of the toes, the size of the talons and how a bird uses its feet are also useful identification characteristics.

                     Wing Structure

        Observation of the structure of  wings which is fully visible when a bird in flight is a good way for identifying a bird.  Here are some main structural parts of wing of a bird. 

Wingtip

Wingtips are easily visible on flying birds, and determining if they are rounded or pointed can help with proper identification. Another clue can be the splay of the primary feathers (how wide the spaces are between each individual feather on the wingtip). Some birds hold these feathers close together, while others spread them widely.

Wrist

The bend of a bird's wing is its wrist—the first joint down from the wingtip—and how that wrist is held can distinguish different species. As with wingspan, it is best to make this judgment when the bird's wings are fully extended and the bird is gently soaring so that the wing is in a rest position. Check to see if the wrist joint is relatively straight or shows a stronger bend, and how that bend compares to the position of the head. At the same time, check for any markings, such as a dark patch or comma-like shape at the wrist.

Patagium

The leading edge of the wing is the patagium, and its color can help identify a bird, such as the dark patagium on the red-tailed hawk pictured above. Check to see if the whole patagium is colored or if it is simply splotched or speckled.

Wingpit

A bird's wingpit is the equivalent to the human armpit, the area close to the body on the interior of the underside of the wing. This area can show distinct colors or markings vital for bird identification. Look for streaks, barring, or color patches on any in-flight bird you're trying to identify.

      Wing Feathers

    While the structure of the wing is often more immediately useful for field identification, field guides often refer to different types of feathers when listing key field marks. Understanding how those feathers look on a wing can help you be prepared to identify each bird you see.

Primary Feathers

The primary feathers are the "fingertip" feathers of the wing and are found at the wingtip.

Secondary Feathers

Secondary feathers make up the back edge of the wing closer to the body. They are generally shorter and closer together than primaries, and birds do not manipulate them as much as they do their primary feathers.

Coverts

Covert feathers make up the wingpit as well as the upper side of the wing, and they cover the base of the primary and secondary feathers. They may be called primary coverts or secondary coverts, depending on which feathers they are aligned with.