Document 182913

How to Identify Birds
Are you amazed at how quickly birders can
identify birds?
Actually, it's just like getting to know your human neighbours. When you move into a
new neighborhood everyone is a stranger, but soon you learn to tell people apart as
you unconsciously catalog their characteristics. Their habits, shape, styles of walking,
and "habitats" become familiar enough that you can recognize each neighbour
immediately, even at a distance.
Paying attention to individual differences can help you identify birds, too. You can
recognize many birds simply by noting their shapes, even if seen only in silhouette.
Other useful characteristics are a bird's posture, size (easiest to judge if you use
familiar birds as a size reference), flight pattern and/or head-on flight profile, and the
kind of habitat in which the bird was seen.
Start by learning to identify general groups of birds- warblers, flycatchers, hawks,
owls, wrens- whose members all share certain similarities. As your observation skills
improve, familiarize yourself with the field marks- colored or patterned areas on the
bird's body, head, and wings- that help distinguish species.
Identifying Bird Groups by Silhouette
Birds vary in size. Silhouette alone
gives many clues to a bird's
identity, allowing birders to assign
a bird to the correct group or even
the exact species.
In this illustration are 23 different
birds. How many can you
recognize just by their silhouettes?
Look carefully - don't miss the ones
hiding in the leafy tree!
Pay attention to the following:
body shape
proportions of the head, legs,
wings, tail shape and length of
the bill
Silhouette Descriptions
Medium-sized finch-like songbird with long tail
Strongly conical, seed-eating bill
Crested head
Large size
Stout body, medium-length tail
Heavy, strong bill
Dabbling Duck
Typical duck shape, with heavy body
Short tail, held above water's surface
Horizontally flattened bill
Plump body, with short legs and neck
Small head
Pointed wings
Slight swelling at base of upper bill
Small to medium size
Conical, seed-eating bill
Notched tail
Silhouette Descriptions
Slender body, long tail
Strong, slightly curved bill
Mid-sized crow-relative with long tail
Some have crest on head
Small bird of prey
Typical streamlined falcon shape, with long pointed wings and long tail
Short raptorial (sharply hooked) bill, feet with sharp talons
Medium-sized perching bird with relatively large head
Broadly-flattened, typical flycatcher bill
Large head, often with shaggy crest
Very short legs and tail
Long, strong, pointed bill
Silhouette Descriptions
Chunky body, short tail
Strong legs
Straight, strong, pointed bill
Long, slender body, long legs and tail
Small, slender bill
Small size, chunky body, short tail
Straight, slightly upturned bill
Strong legs and feet
Clings to tree trunks, usually head downwards
Small to medium-sized shorebird
Relatively large head, short neck
Short, rather thick bill, sometimes slightly swollen at tip
Ground dwelling
Chunky, rounded body, with short tail
Small head, very short neck
Ground dwelling
Silhouette Descriptions
Small nocturnal bird of prey
Chunky body, large head
Feathered tufts on head resemble ears
Upright stance
Medium-sized predatory songbird
Relatively large head
Perches horizontally
Bill with strong hook at tip
Chunky body, short tail
Strong legs and feet
Straight bill
Small size
Very slender body, short legs, and long, pointed wings
Small bill with wide gape
Silhouette Descriptions
Small, tree-dwelling bird
Small, cylindrical bill (slight hook at tip, visible only at close range)
Perches horizontally, often leans forward while foraging
Very small, tree-dwelling bird
Perches horizontally
Slender insect-eating bill
Clings to tree trunks, head upwards
Uses tail as prop as it hitches its way up tree trunks
Strong but short legs and strong feet
Straight, strong bill for excavating wood
Very small size
Compact body, with relatively long legs
Thin, slightly curved bill
Holds tail upright
Skulking habit
Using Field Marks to Identify Birds
In order to describe a bird, ornithologists divide its body into
topographical regions: beak (or bill), head, back, wings, tail, and
legs. To help with identification, many of these regions are
divided still further. This next diagram of regions of the bird's
body shows some of the commonly used descriptive terms.
Birds display a huge variety of patterns and colors, which they
have evolved in part to recognize other members of their own
species. Birders can use these features - known as field marks to help distinguish species.
Pay particular attention to the field marks of the head and the
field marks of the wing.
Bird Topography
Field Marks of the Head
When identifying an unknown bird, the following field marks of the head are particularly important:
Eyebrow stripe (or superciliary line, above the eye)
Eyeline (line through the eye)
Crown stripe (stripe in the midline of the head)
Eyering (ring of color around eye)
Throat patch
Color of the lore (area between base of beak and eye)
Whisker mark (also called mustache or malar stripe)
Color of upper and lower beak
Presence or absence of crest
Beak shape and size are also important identifying characteristics.
Field Marks of the Wing
In a few groups, notably warblers and vireos, the presence of wing markings gives
positive identification even if the bird is in non-breeding plumage. In other groups,
such as flycatchers and sparrows, the absence of any wing markings may be an
important distinguishing characteristic. Note the presence or absence of the following:
Wing bars
Wing patches
Molt and Confusion!
Molt is the process
of which old feathers
are replaced by new.
Molt Pattern
Natal Down (plumage)
Prejuvenal Molt
Juvenal Plumage
Prebasic Molt
Basic Plumage
Prealternate Molt
Alternate Plumage
Prebasic Molt
Basic Plumage
et cetera…
Feather Wear (form of molt)
Feathers are worn not
replaced to reveal
fresh appearance.
Identifying Bird Groups by Posture
Striking a Pose
Posture clues can help place a bird in
its correct group. Watch an American
Robin, a common member of the thrush
family, strut across a yard. Notice how
it takes several steps, then adopts an
alert, upright stance with its breast held
forward. Other thrushes have similar
postures, as do larks and shorebirds.
Vertical Posture
Certain bird groups have distinctive
vertical posture when perched on a
branch. Flycatchers, hawks, and owls
typically sit in an upright pose with tails
pointing straight down.
Horizontal Posture
Other birds perch horizontally on
vegetation with tails pointing out at an
angle, for instance vireos, shrikes, crows
and warblers.
Distinguishing Similar Birds
Distant perched crows and hawks may look alike, but paying attention to their
different postures may help to tell them apart. The Red-tailed Hawk perches upright,
whereas the similarly-sized American Crow perches horizontally.
Using Familiar Birds as Size Reference
Once you have assigned a bird to its correct group,
size can be a clue to its actual species. Be aware,
though, that size can be difficult to determine in the
field, especially under poor lighting conditions or at a
distance. Size comparisons are most useful when
the unknown bird is seen side-by-side with a familiar
species. In the absence of that, you can use the
sizes of well-known birds, such as the House
Sparrow, American Robin, and American Crow, as
references when trying to identify an unfamiliar bird.
Size Reference
Woodpeckers: A crow-sized
woodpecker would be a
Pileated, but one the size of a
sparrow might be a Downy
Woodpecker (or a Ladderbacked Woodpecker in the
Size Reference
Confusing Coloration: A yellow-andblack finch smaller than a sparrow is
probably an American Goldfinch.
Evening Grosbeaks have similar colors
and patterns, but are almost robinsized.
Size Reference
In-between Sizes: Sometimes you
need two reference birds for
comparison. A Cedar Waxwing is
bigger than a sparrow but smaller
than a robin. A Blue Jay is larger
than a robin but smaller than a
Using Flight Patterns as Identification
Most birds fly in a straight line, flapping in a
constant rhythm, but certain bird groups have
characteristic flight patterns that can help
identify them. Birds of prey may be identified
by the characteristic way they hold their
wings when viewed flying toward you. Here
are some useful identification tips:
Flight Patterns
Up-and-down Flight Pattern
Finches exhibit a steep, roller-coaster flight, whereas woodpeckers generally fly in a
pattern of moderate rises and falls.
Flight Patterns
Flapping Versus Gliding
Flying accipiters such as Sharp-shinned Hawks, Cooper's Hawks, and Northern
Goshawks typically make several wing flaps followed by a glide. Buteos, such as the
Red-tailed Hawk, are usually seen soaring. Dashed lines indicate flapping, solid lines
Flight Patterns
Crow Versus Raven
Flight patterns can sometime distinguish similar species. The American Crow, for
instance, flies with deliberate, flapping wingbeats. The similar Common Raven often
alternates flapping with hawk-like soaring.
Head-on Flight Profiles
Head-on flight profiles may also give identity clues. Soaring Turkey Vultures may look
like hawks, but they hold their wings in a shallow V-shape, whereas most hawks and
eagles hold their wings out flat. Black Vultures also have a flatter, more hawk-like
profile. Northern Harriers hold their wings in more of a V-shape, but their slow,
flapping flight near the ground generally gives away their identity. Notice how the Bald
Eagle's profile is even more flat than that of a typical hawk, such as the Red-tailed
Using Habitat Clues to Aid
In general, each species of bird occurs only within
certain types of habitat. And each plant community whether abandoned field, mixed deciduous/coniferous
forest, desert, or freshwater marsh, for instance contains its own predictable assortment of birds. Learn
which birds to expect in each habitat. You may be able
to identify an unfamiliar bird by eliminating from
consideration species that usually live in other habitats.
(Be aware, though, that during spring and fall migration
birds often settle down when they get tired and hungry,
regardless of habitat.)
Habitat Clues
Abandoned Field
Agricultural fields no longer used for
farming form an "old field" habitat as
they slowly revert to forest. In the
Northeast and the Mid-Atlantic
states, the original grasses are
replaced with plants such as
goldenrod, mullein, asters, and
brambles (blackberry). Thickets of
woody shrubs - such as honeysuckle
and multiflora rose - develop, mixed
with small trees such as red cedar,
black locust and hawthorn. Birds
found there include Field Sparrow,
House Wren, Red-tailed Hawk, and
Blue-winged Warbler.
Habitat Clues
Mixed Deciduous / Coniferous
In a broad band stretching from
the Great Lakes region eastward
to New England and the Maritime
Provinces of Canada, the
southern deciduous woodlands
and the coniferous forests of the
north meet and intermingle.
There broad-leafed trees such as
oaks, hickories, beeches, and
maples mix with conifers such as
spruces, firs, and hemlocks.
Birds that live there include
Winter Wren, Northern Goshawk,
White-throated Sparrow, and
Black-throated Green Warbler.
Habitat Clues
Sonoran Desert
The Sonoran Desert is a hot, dry
region covering 120,000 square
miles in southwestern Arizona
and southeastern California, as
well as most of Baja California
and the western half of the state
of Sonora, Mexico. Tall saguaro
cactus and spiny cholla cactus
are common, mixed with trees
such as ironwoods and palo
verdes, and shrubs such as
saltbush, creosote bush, and
mesquite. Black-throated
Sparrow, Cactus Wren, Harris's
Hawk, and Lucy's Warbler can
be found there.
Habitat Clues
Freshwater Marsh
A freshwater marsh is a treeless wetland
whose shallow water supports dense
stands of mostly emergent plants (rooted
in mud but with most of their foliage above
water). Marshes are found throughout
North America, often forming when ponds
and shallow lakes fill in, although beavers
may also play an important role in their
formation. Typical vegetation includes
cattails, bulrushes, sedges and reeds. In
deeper pools submerged and floating
aquatic plants occur, including water lilies,
pondweed, arrowhead, duckweed,
smartweed, bladderwort, pickerel-weed,
water-shield, and sweet flag. Bands of
shrubs such as alder and willow occur at
drier marsh edges. Swamp Sparrow,
Northern Harrier, Marsh Wren, and
Common Yellowthroat are typical
Bird Song
Only a few species of birds have no voice--storks, pelicans, and some vultures.
Most birds produce some sort of vocal sound. The Passeriformes (perching
birds,songbirds) are noted for their singing ability. Many birds are restricted to
vocal sounds rather than songs or calls.
Call- a brief sound of simple acoustic structure- a peep, cheep, squawk, chatter,
Song - a relatively long, often melodious, series of notes usually associated with
some aspect of courtship.
The vocal organ of birds is composed of membranes located at the junction of
the bronchi and called the syrinx. When a bird sings, air from the lungs is forced
through the syrinx and air passing over the membranes causes a sound. Either
one of the two membranes, or both, may be used in singing. Since two different
sounds may be produced, the variation in both loudness and frequency is
The songbirds have the greatest number of muscles in the syrinx (4-9 pairs)
while most other bird groups have only one pair. In general, the complexity of
the syringial muscles is related to the complexity of the songs a bird can
produce. But there are exceptions such as the American Crow, which has seven
pairs of syringial muscles but a limited voice. Parrots on the other hand, can
mimic the human voice and only have three pairs of syringial muscles.
Evolution of Song
Birds evolved from voiceless reptiles. What is the evolutionary advantage of
song for it to have developed to the extent it has?
Alarm notes to frighten predators.
Finding each other in dense vegetation.
As mobility increased with flight, the need for long-distance communication did
As a way of keeping a group together- for protection and during migration.
Non-vocal Sounds
Passerines have the most well-developed songs and calls, but other birds with
less vocal abilities have developed other sounds. Kiwis stamp their feed when
annoyed. Boat-billed Herons, Storks, and Albatrosses rattle or clap their bills.
Woodpeckers drum. The Ruffed Grouse drums with its wings. The nighthawk
and hummingbirds often make sounds with their wings or tails. A number of
birds make whistling sounds as they fly through the air- may or may not serve a
Function of Song
Bird songs are basically related to reproductive activities in one way or another. Calls may be related to
reproductive or self-maintenance activities. Some specific functions of song:
Proclaim sex/induce another bird to reveal its sex. There is a correlation between the complexity of the
song and dull plumage and little or no sexual dimorphism. The duller the plumage and/or the more the
sexes look alike, the more complex the song (e.g. Song Sparrows).
Attract a mate. True for many species.
Establish a territory. Often, males arrive on the breeding grounds before the females (e.g. Red-winged
and Yellow-headed Blackbirds); singing establishes the territory and maintains it later.
Stimulate and synchronize courtship behavior. Indicates readiness to breed by both sexes.
Maintain pair bond. A female Song Sparrow will come off the nest and sing back to her mate.
Signal changes in domestic duties. May trade feeding or incubation duties, signaled by song.
Identify individual to young. Most precocial birds can recognize their own young - waterfowl and
penguins, e.g. Experiments with Mallards indicate that communication between the female and young
begins before hatching.
"Species" identification. A song or call may be given to identify a bird of the same species or population.
Hold flock together. Calls, usually, but often songs, are used to coordinate the movement of a flock; e.g.
Pygmy Nuthatch, Mountain Chickadee.
Intimidate enemies. May be use to scare predators.
To perfect song through practice. Often, complex songs are learned through imitation and practice.
Basically a bird’s song is a very specific type of communication. If a predatory bird is
perched conspicuously in a tree small birds will often make themselves known by a
behavior called mobbing; they set up a chorus of calls around the predator to point it out
and perhaps chase it away. But if the predator is flying overhead, the small birds race to
the nearest bush or tree and utter their calls from there.
Many birds have warning calls that are species-specific. Crows give a warning call that will
frighten away only other crows - this call has been recorded and used to scare other crows
from cornfields.
Starlings roost in trees in cities and can be pests; they can also be driven away by speciesspecific calls Robins and Grackles in the same flock are not affected. But in other cases,
such as that of the Herring Gull, their alarm call will also scare away the Great Blackbacked and the Laughing Gulls.
Parent birds can call to their young to make them ‘freeze’ in the presence of a predator,
swim, peck at food, etc. Young birds can vocalize in such a way as to stimulate a parent to
feed them, etc.
Song is typically the function of the male, but there are many exceptions. The female
Mockingbird, Cardinal, and Black-headed Grosbeaks have songs as complex as the
males’. In the phalaropes, where sexual dimorphism and courtship roles are reversed, the
female only sings. And if females hold individual territories in the winter, they may sing then
even though they don’t sing during the breeding season.
Song Variation and Song Ecology
Each bird species exhibits a more or less characteristic song, but the song varies by age, sex, geographic location, and time
of year.
Populations of the same species of birds having different songs are song races; each variation in a song is a dialect. The
white-crowned Sparrow is well-known for having many song races and dialects. Geographic variation in song is very
common. But within different populations of the same species, the song is more stereotyped (less variable) when there are
other species present with similar songs. But when no other species with similar songs are present, there is more variation in
the song within a population of one species. More variation is not only allowed, but it helps the recognition of single
Ecology of Song
Males of many bird species use a singing post to call their mate or establish territory from - tree. post, wire, etc. Other birds
the live in grasslands like the Horned Lark or Bobolink have a flight song. Birds living in dense vegetation such as in
rainforests or thick reed beds have loud voices since vegetation absorbs sound as well as obstructs vision. So birds have
evolved calls and songs at least partly in response to the structure of the habitat in which the call is given. Weather also has
an influence on bird song. Both cool and hot weather decrease the amount of singing, as do rain and wind.
A few species such as the Red-eyed Vireo sing more or less all day. But most birds sing more vigorously in the early
morning and evening when there is less light. Some species sing at night, such as the Mockingbird and Nightingale. The
amount of light rather than the time of day determines the beginning and end of singing. Cloudiness in the morning, for
instance, will delay singing. Different bird species react to different amounts of sunlight. So some species in a particular area
will begin to sing before others chime in (Dawn Chorus). The dawn chorus may begin at different times each day, depending
on the amount of light, but the bird species will begin singing in the same order.
Most birds show a seasonal variation in some that is mainly correlated with breeding activities and hormone production. The
richest, fullest song generally comes in the spring when birds are establishing territories and courting (unmated males sing
more). After egg-laying commences, the birds sing less so as not to attract predators.
If a male bird renests or its mate is killed, it resumes full singing. In the fall after the breeding season, the bird stops unless it
holds a winter territory.
Inheritance and Learning of Song
Generally, calls are genetic while songs are partly inherited and partly learned. Many studies have been
done of song development; the classic one is the one done in England on the Chaffinch. The full song of
the male Chaffinch performs the function of keeping other males from its territory and attracting females.
This song is described as: ‘chip-chip-chip, tell-tell-tell, cherry-erry-erry, tissy-chee-wee-oo’
So what’s happening? In the wild, young Chaffinches learn some details of song from their parents or
from other adults in the first few weeks of life. At this stage a young bird absorbs the general pattern of
the song. But not until the critical learning period the following spring does the bird develop the fine
details of the song. This is the time the young wild Chaffinch first sings in competition with other
Chaffinches (for females, territory) and it learns the details of the song from its more mature neighbors.
This, of course, leads to a bit of individual variation in song, although the general pattern is characteristic
of the species. So song is an integration of both genetic and learned components and calls are entirely
Song Mimicry
A large number of birds exhibit varying degrees of vocal mimicry and imitate call notes of songs of other
species. The Starling frequently mimics the Killdeer or nighthawk. Scrub and Blue Jays can imitate a
Red-tailed Hawk.
The Mockingbird (and others in the family- Catbird, Brown Thrasher) are well known for imitating other
bird’s calls. But there is no evidence to indicate that these calls are an attempt to communicate with the
other species. They may, in fact, only be a human interpretation as birds hear songs much differently that
we do. A Bullfinch in England was taught to whistle the English National Anthem. A lyrebird in Australia
learned to whistle the noon whistle at a factory.
Parrots, mynahs, crows, and magpies apparently only mimic in captivity. And their imitation of a human
voice is very different acoustically than the real human voice.
Learning Birdsong
If you are like me, your birdsong identification skills
often need a few repairs after the long winter.
Synapses dissolve, things come unwired - who
knows what goes on up there, but a tune-up is
definitely in order. Others of you may be venturing
into the world of birdsong for the first time. You're
sick and tired of that birding buddy who identifies
every peep in the bush before you've even raised
your binoculars. This is the year you get your
Learning Birdsong
To use bird vocalizations effectively as a means of
identification (and that's what this is all about) you
need some basic methods of representing the songs
and calls. One familiar means is phonetics. This
method employs sound units to mimic the
vocalizations themselves. The words "chickadee"
and "bobwhite" remind us of the sound the bird
actually makes. Although many phonetic
representations can be found in field guides, you will
improve your birdsong ID skills by making up your
own phonetics.
Learning Birdsong
Another good way to represent birdsong is with written
descriptions. Again, there are many examples in field guides.
Here too, certain descriptions will work for you to help you recall
the song and the songster - others will fall flat. Don't settle for a
description that's not right for your ears - make your own.
Mnemonic (a pattern of letters or words formulated as an aid to memory)
Yellow Warbler “sweet sweet sweet, I'm so sweet”
American Robin “Cheerily, cheer-up, cheerily “
Olive -sided Flycatcher “Quick, three beers”
Barred Owl “Who cooks for you, who cooks for you'all”
Learning Birdsong
A third method for learning and recalling
birdsong involves diagrams or drawings.
Depending on your learning style this may or
may not work for you. Try making a drawing
of the vocalizations that you hear.
Learning Birdsong
Now that you've had an opportunity to try all
three methods of representing birdsong you
should think a bit about your own personal
learning style. To most effectively learn
birdsong you will probably want to combine
the methods that work best for you.
Seeing Bird Song
Two people attempting to describe a Green-tailed Towhee song verbally may conjure two
entirely different sound images. Both would agree that it includes some whistle-like
phrases, some trills and some buzzes. But such a description is most unsatisfying to
anyone who has never heard the song. It is equally unsatisfactory for the ornithologist
wishing to examine questions of individual repertoire size and variation, the amount of song
and syllable sharing among individuals, the existence of dialects, or the degree of
geographic variation in songs among populations. With the development of the sound
spectograph or sonagraph, it became possible to objectively and quantitatively approach
these questions, and the sonagraph has been used in an impressive number of studies
over the past 25 years. This work has been facilitated by the development of high-quality
portable tape recorders used in conjunction with microphones mounted in parabolic
reflectors or with very sensitive directional microphones.
The sonagraph produces on paper a graphic picture (a sonagram) of sound showing
frequency (measured in kilohertz—thousands of cycles per second) on the vertical axis and
time (in seconds) on the horizontal axis. Thus displayed, complex songs can be objectively
separated into their constituent components, as shown in the sonagram (below) of a
Green-tailed Towhee song. The song consists of an introductory note-complex followed by
a buzzy trill, another note-complex, a trill composed of separable, repeated syllables, a
single note, and ends with a buzzy trill of essentially continuous syllables.
Seeing Bird Song
Foraging Behavior as I.D Clues
Learning takes time
Learn basics first
Learn from experience
Learn “in the field”
Listen to songs
Have fun
Join bird watching club
Hooooo am I?