What Group Best Fits The Bird You Want To Identify?

Hawks, Falcons, & Eagles

,Owls, Vultures

See Visual Types andSilhouette Comparison

Predatory Birds

Grouse, Quails, Pheasants, & Turkeys

, Pigeons & Doves

, Goatsuckers & Nighthawks

See Visual Types andSilhouette Comparison

Upland Ground Birds

Cuckoos, Woodpeckers,

Swifts & Hummingbirds

See Visual Types andSilhouette Comparison

Perching & Tree-clinging

Tyrant Flycatchers, Larks, Swallows, Corvids , Chickadees, Nuthatches & Creepers, Wrens & Dippers, Kinglets & Gnatcatchers, Thrushes, Thrashers, Pipits,

Waxwings, Shrikes, Starlings, Vireos, Warblers, Tanagers, Sparrows, Grosbeaks, Icterids, Fringillids

Song Birds

Loons, Grebes, Pelicans & Cormorants,

Bitterns, Herons, & Ibises, Swans, Geese, & Ducks,

Shorebirds, Gulls & Terns, Rails, Coots & Cranes,

Kingfishers

Waterfowl & Marshland Birds

See Visual Types andSilhouette

Comparison

Spotted Towhee(Pipilo maculatus)

American Goldfinch(Carduelis tristis)

American Robin(Turdus migratorius)

Northern Harrier(Circus cyaneus)

Red-tailed Hawk(Buteo jamaicensis)

Barn Swallow(Hirundo rustica)

Northern Rough-winged Swallow

(Stelgidopteryx

serripennis)

Tree Swallow(Tachycineta bicolor)

Brewer’s Cowbird(Euphagus cyanocephalus)

Red-winged Blackbird(Agelaius phoeniceus)

Osprey(Pandion haliaetus)

Turkey Vulture(Cathartes aura)

Western Scrub-Jay(Aphelocoma californica)

Yellow Warbler(Dendroica petechia)

Belted Kingfisher(Ceryle alcyon)

Double-crested Cormorant(Phalacrocorax auritus)

Wood Duck(Aix sponsa)

Mallard(Anas platyrhynchos)

Black-capped Chickadee(Poecile atricapillus)

Northern Flicker(Colaptes auratus)

European Starling(Sturnus vulgaris)

Cladogram of Tetrapods:Am

phib

ians

Synap

sids

Turtl

es

Sphen

odon

Liza

rds

Snake

s

Cro

codi

les

Birds

Diapsids (“two arches” - Greek)

Sauropsids (“reptile-like appearance” - Greek)

Amniotes

Reptiles

Squamates

Lepidosaurs Archosaurs

“Ruling Reptile”

Group includes dinosaurs(Read chapter 16 (VL) to

your hearts content…)

Birds: (~ 30 orders; ~ 193 families; ~ 9700 species)

Evolution:

• First appearance in fossil record = Jurassic

Class: Aves

Archaeopteryx:

The Original Link Between Birds and Reptiles

Birds

Reptilian Features:

1) Non-keratinized snout

• Teeth present

2) Trunk vertebrae not fused

3) Neck attaches to skull from rear

4) Long tail with free vertebrae

5) Ankle / wrist bones free

Avian Features:

1) Feathers

2) Opposable big toe (hallux)

3) Furcula (wishbone) present

Most likely capableof sustained flight

~ 1.5 km / 40 kph

Believed evolvedFrom theropods

(velociraptor)

Birds

Mastery of flight opened a world of ecological opportunities…

1) Streamlined body:

• Similar to reptilian scales (beta-keratin – present in birds / reptiles)

• Retain scales on non-feathered parts

Avian Anatomical Adaptations for Flight:

vs.Reduced resistancewhen moving throughair…

???

2) Feathers:

• Hypotheses: 1) Insulation to retain heat (not endothermic…)

2) Social interactions (e.g., reproduction)

3) Shading / insulation for eggs

Feathers appear in fossil record long before flight (e.g., Caudipteryx)

• Current Functions of Feathers:

• Dead structures; damage repair = replacement

• Specialized pockets of epidermal / dermal cells (follicles)

Birds

Avian Anatomical Adaptations for Flight:

2) Feathers:

A) Contour Feathers (flight feathers – vaned…)

• Long central shaft (rachis)

• Broad vane with numerous barbs

• Barbules hook barbs together

• Calamus (quill) anchors feather in follicle (skin)

• Mobile – individual muscles control each feather

• Stream-lined; decreases drag

• Asymmetrical & curved (independent airfoils)

B) Filoplumes (Provide sensory information)

• Long rachis with few barbs at end

C) Down Feathers (Insulation)

• Lack central shaft; barbs from feather base

• lack barbules; barbs move freely

Feather Tracts:

Feather attachmentsgrouped in dense

concentrations

2000 – 4000 feathers(~ 15% BW)

Birds

Avian Anatomical Adaptations for Flight:

2) Feathers:

• Range from drab to colorful…

A) Biochrome Pigments

• Melanins = earth tones (e.g., grays / blacks / browns)

• Resist feather wear (e.g., black wing tips resist fraying)

B) Structural Colors

• Result from physical alteration of light (e.g., iridescences)

• Nanometer-scale structuring in feather:

1) Air bubbles = White (unpigmented feathers)

High UV reflectance (birds capable of detecting UV light!)

• Resist bacterial degradation (wet climate = dark color)

• Absorb energy (thermoregulation / feather drying)

• Carotenoids = vibrant colors (e.g., bright yellows / oranges / reds)

• Derived from diet (honest signaling…)

• Porphyrins = vibrant colors (e.g., bright brown / green / magenta)

• Chemically related to hemoglobin

2) Melanin granules (melanosomes) = iridescenceCan occurtogether…

Yellow-thigh Parrot

Budgie

Birds

Avian Anatomical Adaptations for Flight:

2) Feathers:

• Feather care important…

• Birds go through series of feather coats in lifetime

• Molt: Replacement of entire plumage (= feather coat)

• Preserves feather moistness / flexibility

• Cleans / waterproofs feathers

• Regulates bacterial / fungal growth

• Repel would-be predators (foul-smelling)

• Uropygial (Preen) Gland:

• Located at base of rump

• Secrete rich oil (waxes / fatty acids / fat / water)

Juvenile Adult Non-breeding Breeding

• Seasonal display

• replace feather wear

• parasite infestations

Birds

Avian Anatomical Adaptations for Flight:

3) Bones:

A) Pneumatic: (air-filled; reinforced with internal struts (= trabeculae)

• Reduced weight (but see diving birds…)

B) Number reduction: (weight)

• No teeth

• Carpal / tarsal bone reduction

• Digits lost

C) Fusion: (strength / stability)

• Thoracic vertebrae fused (platform)

UncinateProcesses

• Synsacrum (pelvic support)

• Pygostyle (tail feather support)

• Furculum (wishbone – “spring”)

• Carpometacarpus / Tarsometatarsus

D) Additional Modifications

• Keeled sternum (muscle attachment)

• Enlarged humerus (major force…)

• Muscle reduction

• Jaws – power not necessary (food swallowed whole / in chunks)

• Legs – rigid skeleton provides support; perching only major requirement

• Muscle centralized on proximal portion of limb (center of gravity)

Avian Anatomical Adaptations for Flight:

4) Muscles:

Birds

• Both up-stroke (supracoracoideus) and down-stroke (pectoralis) muscles originate on keel

5) Forelimbs Modified as Wings:

Airfoils togenerate

lift…

• Flight muscles

• Size increase; location near center of gravity

Evolution of Active Flight:

“From the Tree Down” Theory of Flight:

• Early ancestors tree climbers – jumped from tree to tree

Gliding Weak Flapping Full Airborne Flapping

“From the Ground Up” Theory of Flight:

• Early ancestors fast bipedal runners – “wings” lightened load

• Flapping evolved to provide additional forward propulsion

• Early ancestors used “wings” to snare insects

• Flapping evolved to assist horizontal jumps for prey

• Early ancestors used wings to run up steep slopes

• Wing Assisted Incline Running

Flight:

“Arborealists”(ornithologists)

“Cursorialists”(paleontologists)

Parachuting (drop with little control)

Gliding (membranes = lift)

Soaring (utilize wind currents)

Passive Flight (requires little energy…)

Active Flight (requires lots of energy…)

• Selective pressure favored increased distance / lift

Cost / Benefit of Flying:

Metabolic / Energetic Requirements for Flight:

• Reduction in Weight (= reduce cost of flight)

• Visceral organs small but efficient; pneumatic skeleton

• High Metabolic Rate ( ability to sustain muscle activity)

• Endothermy: Core temp. sustained by heat released from metabolic processes

• Advantages:

1) Faster response time for brain / muscles

2) Activity levels maintained in cold environments

• Disadvantage: caloric intake required

Birds

Flight:

Costs: Benefits:

• Energetically costly (short-term)

• Limits range of body size

• cost / unit distance

• Exploitation of new resources

• Escape from predators

1% of energy expendedper mile covered (versus mouse)

Birds = variation than other verts. 64,000x vs. 50,000,000x

Bird’s core temperature higher than similar sized mammal

Required Modifications for Endothermy:

1) Cardiovascular System

• Larger, more muscular heart

• blood flow / blood pressure

• Separation of O2-rich / O2-poor blood

• blood flow to lungs

3) Insulation (= feathers)

• hemoglobin concentration in blood

2) Respiratory System

• exchange surface / unit lung volume

• Unidirectional air flow (no mixing of fresh / stale air)

Flight:

Birds

Mechanics of Wing Design:

• Two types of contour feathers present on wing:

1) Primaries: Located on hand; provide thrust

2) Secondary: Located on back of arm; provide lift

• Force produced as air passes wing:

1) Lift = Vertical force equal to or greater than weight of bird

During upstroke, air passes betweenflight feathers = cost reduction…

A) Cambered Airfoil• Upward curvature of wing; tapers toward back

• Ventral = High pressure; Dorsal = Low pressure

B) Angle of Attack• Leading edge of wing tilted; pressure dorsally

• Stalling angle = airflow separates from wing (~ 15º)

• Alula “Bastard wing” • Reduce drag by improving air flow over wing (= steeper angle of attacks)

Bernoulliprinciple

• camber allows for flight at slower speeds

Birds

Mechanics of Wing Design:

• Force produced as air passes wing:

2) Drag = Component opposing forward movement; created by turbulent air flow

Ratio = wing span / wing width

Low Aspect Ratio = Wide, short wings (higher drag)

High Aspect Ratio = long, narrow wings (lower drag)

• Wing Loading: (Ratio = body mass / wing surface area)

• Correlates to size – body mass faster than surface area as body size • Low Wing Loading = more maneuverable; power needed to sustain flight

• High Wing Loading = less maneuverable; often soaring birds

• Highest at tips of wings

• Reduce effect = 1) Taper wing

2) Lengthen wing

• Aspect ratio = measures amount of wing drag produced, relative to lift

Flight:

Birds

Major Structural Wing Types:

Characteristic

SparrowRobinPigeon

SwallowDuck

Falcon

albatrossshearwater

petrel

eaglevultureraven

Elliptical(short & rounded)

High Speed(Taper to point)

Dynamic Soaring(Long & narrow)

High Lift(Long & broad)

Camber

Alula

Speed

Acceleration

Maneuverability

Endurance

Aspect Ratio

Wing Loading

Examples:

High Low Very low High

Large Absent Absent Large

Slow Fast Fast Slow – Mod.

Fast Slow Slow Fast

High Moderate Very Low High

Low High Very High Moderate

Low (3 – 6) Moderate (5 – 9) Very high (9 – 18) Moderate (6 – 7)

Low (small birds)Low (small birds)High (large birds)

Moderate - High Moderate(can pick up weight)

Birds

Reproduction:

Birds

• Utilize colors, postures, and vocalizations for species, sex, and individual identification

• Bird Song: Complex array of notes, often with frequency modulation

• Often male specific and during breeding season

• Learned behavior; “window” of opportunity during development

• Species specific; regional dialects relatively common

• Function:

1) Attract mates

2) Repel rivals

• Visual displays often associated with song:

• ♀♀ select males based on visual characteristics :

“truth in advertising…”

• Good nutritional status

• Low parasite loads

• Predator avoidance ♀♀ prefer ♂♂ with longertails and more eye spots

Offspring grew faster; survival rates

Reproduction:

Birds

• Birds exhibit two broad categories of mating systems:

1) Monogamy: Pair bond between single male and female (~ 90% of bird species)

2) Polygamy: Individuals mate with > one partner during single breeding season

• Polygyny = Single ♂ – multiple ♀♀; Polyandry = Single ♀ / many ♂♂

• Both parents required to raise young (e.g., food acquisition)

• Resource distribution (even – control impossible…)

• Skewed sex ratio (partner becomes prized “resource”)

MONOGAMY does not necessarily mean FIDELITY

• Extra-pair copulation common

• Better quality mate

• Increased heterozygosity

• “hedging” your bets

Resource defensepolygyny

Male dominancepolygyny

Lek:

Aggregation ofmany males

Resource defensepolyandry

Reproduction:

Birds

• All birds are oviparous Why?

Constraints based on flight

• Genetic sex determination

• Heterogametic chromosomes – ♀♀ = WZ / ♂♂ = ZZ

• Most likely ancestral reproductive mode

• No pressure to evolve vivipary (e.g. endothermy = incubated eggs always warm)

• Nests protects eggs from physical stresses and predation:

Colonial NestingProtection in numbers

Shallow depression(e.g., Killdeer)

Elaborate structure(e.g., osprey)

Brood Patch

Feathers lost;Blood vessels proliferate

Stimulated by prolactin

Egg Incubation~ 33 – 37 ºC

Megapodes bury eggs

Reproduction:

Birds

• Clutch size variable:

1) Trade-off Hypotheses: Driving force is maximization of lifetime reproductive success

• Physical strain on females / exposure to predation during food collection

2) Predation Hypotheses: Driving force is minimization of nest detection by predators

• More eggs / young = detection (sound / smell / trips to nest / etc.)

3) Seasonality Hypotheses: Driving force is food availability during breeding season

• More eggs / young = food reserves / competition

• Young at differing levels of development at hatching:

Infanticide

Precocial Semiprecocial Altricial

High yolk Moderate yolk Low yolk

Down present Down present Down Absent

Eyes open Eyes open Eyes closed

Mobile Semi-mobile Not mobile

Self-feeding Not self-feeding Not self-feeding

Ducks Hawks Passerines

Incubation may lastfrom 10 – 80 days

Altricial < Precocial

Growth Rates:

Altricial > Precocial

Ducks: (~ 35 species in North America) Shared Characteristics:

1) 3 front toes completely webbed

2) Penis present in males

3) Bill typically flattened / blunt-tipped

Birds

Characteristic

Legs

Feet

Feeding

Diet

Wings

Flight

Habitat

Examples

Dabbling Ducks

Northern ShovelerAmerican Widgeon

Cinnamon Teal

Diving Ducks

RedheadCanvasback

Lesser Scaup

Sea Ducks

BuffleheadEider

Merganser

Relatively long;centered under body

Short but strong;set far back on body

Short but strong;set far back on body

Smaller Larger; long outer toes Larger; long outer toes

Dip head underwater;skim surface with bill

Dive from surface;wings pressed to body

Dive from surface;wings open (steer / paddle)

Invertebrates;aquatic vegetation

Invertebrates Invertebrates;fish (rare)

Big, broad wings;lower wing loading

Smaller wings;higher wing load

Smaller wings;higher wing load

More maneuverable;can fly slow

Less maneuverable;need room to take off

Less maneuverable;need room to take off

Shallow edges of lake;surface in deeper areas

Center of lake;deeper water

Marine coastlines;fast, clear streams

Duck Life Histories:

Mating Behavior:

• Initiated late fall / early winter (wintering grounds / migration)

• Skewed sex ratio – many ♂; fewer ♀

• Form monogamous pair bond (seasonal)

• Males attract females via:

1) Visual Displays:

• Coloration (♂s more colorful than ♀s)

• Most elaborate in dabblers

Tufted Duck – head raise

Ruddy Duck – tail raise

Dabbler Specialty:

Iridescent speculum on wing

Lift wing to display speculum

2) Vocal Displays (primarily dabblers)

• Dabblers have louder, deeper voices

Birds

Ducks: (~ 35 species in North America)

Nesting Characteristics:

• Location of Nest:

• Dabblers = Ground

Merganser

Mallard

Scaup

• Age at 1st reproduction:

• Dabblers / Divers = 1 year

• Sea = 2-3 years

• # of Eggs in Nest:

• Dabblers / Divers = 8 – 12 eggs

• Sea = < 8 eggs (space issues in cavity)

• Sea = Tree cavities

• Divers = Emergent / Floating vegetation

Incubation:

• Females only (20 – 30 days)

• Pair bond only lasts until eggs are laid

Parental Care:

• Females: 2 – 6 weeks; guard from predators

Duck Life Histories:

Ducks: (~ 35 species in North America)

Birds

Brood parasitismdoes occur…

Duck Life Histories:

Seasonal Migration Patterns:

• Benefit = Net increase in lifetime reproductive output

• Spring – Summer:

• Breed at high latitudes (e.g., Canada / Alaska; long days = increased foraging)

• insect population for young

• Fall – Winter:

• Fly south to avoid physical stresses of extreme cold / lack of food

• Costs = 1) death rate for young

2) food acquisition for energy to travel

3) Restricted stops (fewer wetlands to choose from)

Reduce Cost…

4 major N-S flyways in North America(Ducks heading to Alaska…)

50%10%25%

10%• Fly at night; usually < 1000 ft.

• Variety of orientation methods:

• Sun / star compasses

• Magnetic field

Birds

Ducks: (~ 35 species in North America)