1. Aves Bio 2

2. Class Aves Feathers No teeth Flexible long neck – One occipital condyle Scales on legs Bones with air spaces Endothermic Four chambered heart

3. Evolution and Classification Birds are Vertebrates of the Class Aves The evolution of warm- blooded, has enabled birds to survive in virtually every known environment

4. Origin and Early Evolution Evidence from fossils and from studies of comparative anatomy indicates that birds evolved from reptiles Their features and their fragile hollow bones do not preserve well.

6. Caudipteryx Feathered dinosaur Flightless Transitional fossil – Dinosaur arms – Dinosaur teeth Only front of upper jaw – Bird feathers

7. Archaeopteryx 147 MYA Transitional fossil – Characteristics of reptiles – Characteristics of birds

8. Archeopteryx Reptile characteristics – Teeth – Boney tail – Fingers with claws Bird characteristics – feathers

9. Classification Most taxonomist classify the nearly 9,000 species of Class Aves into 27 orders To classify birds into orders and families taxonomists most often use morphological evidence from beaks, feet, plumage, bone structure, and musculature.

10. Endothermic Warm blooded Ability to generate heat & maintain a constant body temperature Can live in hot or cold climates Requires more food Requires faster body processes to generate heat

11. Feathers Uses – Flight – Insulation – Water proofing Homologous to scales of reptiles Colors from – Pigments associated with epidermal cells – Striations in barbs Shed continuously (except Penguins) Accelerate at different times of year (molting)

13. Contour Feathers Hollow quill Rachis subdivided into barbs Barbs connected by barbules When used in flight, called flight feathers

14. Down Feathers No barbules Found beneath contours Conserve head Abundant in waterfowl

15. Filoplumes Degenerate Hair-like Usually two at base of contour Possibly sensory in function

16. Powder Down Similar to down feathers – Tips disintegrate – Produce talc-like powder – Waterproofs animal

17. Feathers Used in many ways Flight Regulation of body temperature (thermoregulation) Protection of the body Attraction of mates Identification of species

18. Feathers Modified scales Provide lift for flight & help conserve body heat

19. Types of Feathers Contour feathers cover the body of a bird and have a strong, hollow shaft and network of hooks. Down feathers are small and are located under the contour feathers to insulate the bird from the cold.

20. Feather Anatomy Rachis – stiff “backbone” of feather Barb – branch off of rachis Barbule – connect barbs Calamus =Quill the hollow horny barrel of a birds feather.

23. Contour Feathers Flight feathers - remiges Tail feathers - rectrices Act as brakes and a rudder Most birds have 12 tail feathers

24. Contour Feathers

25. Contour Feather

26. Lacking Barbules in Owl Feathers = Quiet Flight

27. Preening A bird spends part of each day making minor repairs to tears in its feathers Feathers are re- zipped

28. Preening Zips the Feathers BeforeAfter

29. Feather Growth

30. Down Feathers Soft & fluffy Cover the body of nestlings Provide an undercoat insulating adult bird

31. Filoplumes Called pin feathers Hairlike feathers under contour feathers on body

32. Wings

34. Flight Forces

35. Bernoulli’s Principle

38. Wing Types Elliptical – Low aspect ration (ratio of length to average width) – Greater maneuverability High speed – High aspect ratio – Stay aloft at low speeds

39. Wing Types Dynamic soaring – High aspect ratio High lift – Heavy, large bodies – High lift at low speed

41. Keeled Sternum and Furculum

42. Adaptations for Flight Enlarged sternum – Flight muscle attachment Long neck – balance

43. Adaptations for Flight Reduce body weight – No teeth – No urinary bladder

45. Thermals & Air Currents

46. Skeleton Strong yet light bones Pneumatized space with cross struts Spaces extend to air sacs of respiratory system Birds not any lighter than other mammals of same size – Distribution of weight over legs provide lower center of gravity – Aerodynamic stability

47. Skeleton The sternum supports the large breast muscles The humerus, ulna, and radius, along with the pectoral girdle and the sternum, support the wing. The pygostyle, the terminal vertebra of the spine, support the tail feathers, which also play an important role.

48. Skeleton Several parts fused to increase rigidity Ribs brace each other in addition to attachment to vertebrae & sternum (braces are called uncinate processes) Clavicles fused to a furcula (pulley bone in chickens) which flexes during flight

49. Muscles Pectoralis largest – Downward beat of flight Surpacoracoideus raises wings Pectoralis connects to humerus with keeled sternum. Surpacoracoideus connect to coracoid bone with keeled sternum

50. Beaks and feet Hawks and eagles have powerful break and clawed talons that help them capture and then rip their prey. Swifts have a tiny breaks that opens wide like a catcher’s mitt to share insects in midair. The feet of flightless birds, on the other hand are modified for walking and running

51. Feet Mostly bone, scales and skin Keeps bird from feeling cold and heat at foot Perching due to special tendons

52. Feet

55. Woodpecker & Honeycreeper Tongues

58. Beak Adaptations Ripping flesh

59. Beak Adaptations Eating seeds

60. Beak Adaptations Sucking nectar from flowers

61. Beak Adaptations Drilling wood

62. Beak Adaptations Catching fish

63. Beak Adaptations Basket-like bill to hold fish caught under water

64. Beak Adaptations Filtering

66. Circulatory System 4 chambered heart Closed system Separation of respiratory and systemic circulations Right aortic arch leads to dorsal aorta (left in humans) Larger the bird, slower the heartbeat

67. Circulatory System 4 chambered heart Right and left sides completely separated Right side receives deoxygenated blood from the body and pumps it to the lungs Left side receives oxygenated blood from the lungs and pumps it to the rest of the body Has a single aortic arch Most birds have a rapid heart beat compared to other vertebrates-Hummingbird-600 times a minute Chickadee

68. Respiratory System Nine air sacs – Connect to lungs and centers of bones – Cools the bird Fresh air always moving – No dead ends as in mammals Each wing beat moves air – Never run out of air

69. Respiratory System 9 interconnecting air sacs paired in thorax and abdomen – Divide into extensions to bones Branches of bronchi don’t end in alveoli as in humans – Form parabronchi – Then into air sacs

70. Respiration

71. Takes two passes through respiratory system for a single “breath”

72. Respiratory System When bird exhales the carbon dioxide-rich air from the lungs, oxygen rich air is forced out of the posterior air sacs into lungs via small air tubes

73. Feeding & Digestion Diet – Euryphagous (omnivores) – Stenophagous (select diet) Large appetites due to high metabolic requirements No teeth Gizzard for grinding (keratinized plates) Proventriculus adds gastric juices Crop stores food Caeca – where small intestine joins cloaca – Hold bacteria in herbivorous birds Young birds have bursa of Fabricius – Process B cells of immune system

74. Digestive System Crop – Storage Proventriculus – Enzymes Gizzard – Grind food Cloaca – Waste – Reproduction

75. Digestion – Crop & Gizzard

76. Excretion – Uric Acid Uric acid metabolic excretion (Saves water) Urea Ammonia

77. Excretory System The avion excretory system is also efficient and light weight The two kidneys filter a nitrogenous waste called uric acid from the blood  highly concentrated uric acid travels by ducts called ureters to the cloaca, where along with undigested matter from the intestines, it is excreted in a semisolid, usually white mass

78. Nervous System Birds have a large brains, relative to their size Cerebellum coordinates movement Cerebrum controls complex behavior patterns such as navigation, mating, and nest building Optic lobe receives and interpret visual stimuli Have good color vision

79. Nervous system Birds large eyes are located near the sides of its head, giving a bird a wide field of vision Birds with eyes near the front of the head have better binocular vision Hearing important to nocturnal species Birds lack internal ears-ear canal leads to a tympanic membrane, called an eardrum Sense of smell is poorly

80. Vision Up to 8 times keener than human vision Each eye moves indendtantly

81. Vision Similar to humans Rods & cones

82. Migration & Navigation Most have established routes ½ of all species migrate – Most from north to south in fall and south to north in spring Parameters of migration – Use of different routes in fall and spring – Time to complete route – Night vs day migration (or both) – Distance of migration – Use of landmarks

83. Direction Finding Factors – Use of topographical landmarks – Flock behavior by following experienced birds – Innate sense of time – Use of earth’s magnetic field – Celestial clues (both stars and sun) Sun-azimuth orientation (use of sun and innate sense of time)

84. Migration When temperatures drop and the food supply dwindles, these birds migrate to warmer climates. Some species monitor the position of the stars or the sun. Others rely on topographical landmarks, such as mountains. Magnetic cues, changes in air pressure, and low –frequency sounds may also provide information to migrating birds.

85. Migration Sissor-tailed flycatchar Migates to Central and South America in October Returns in April

86. Migration Arctic tern Migrates 25,000 miles!

87. Behavior Complex behavior – Breeding – Nesting – Courtship – Feeding, etc.

88. Sexual Selection

89. Reproduction

90. Males with paired testes Females often have only left ovary and oviduct Males typically have no penis (waterfowl do) Egg captured by oviduct (infundibulum) Yolk added, then shell Sperm remains viable in some species 5-6 days

91. Nesting & Development Simple and complex nests Altricial and precocial

92. Development and Behavior

93. Incubation and Development A female bird usually lays eggs in the nest. One or both parents will incubate or warm the eggs by sitting on them. The cover them with a thick, featherless patch of skin on their abdomen called a brood patch. In penguins the male emperor heats the egg by placing it on his webbed feet and enfolding it with his warm abdomen.

94. Territoriality and Courtship During the breeding season many male birds establish an area that they defend against other males of their species, a behavior called territoriality. The male then attempts to attract a female to share this territory.

95. Nest Building Nests hold eggs, conceal young birds from predators, provide shelter from the elements, and sometimes even serve to attract a mate.

96. Starling Nests

97. Weaver Bird Nest

102. Brood Parasitism Cardinal or Cowbird eggs?

103. Migration

105. Bird Brains

106. Benefits of Birds to Man Eat insects, rodents and weeds Spread seeds for flowers and trees Food Sport Pets

107. Fastest Animal Peregrine falcon Strikes prey at 180 mph

108. Elephant Bird Eleven feet tall 1100 pounds Largest egg ever Extinct in late 1600’s

109. Giant Moa New Zealand Hunted to extinction about 1600

110. Bird Classification 28 orders 9600 species

111. Order Struthioniformes Large flightless bird Two toes

112. Order Pelecaniformes Gular sac

113. Order Ciconiiformes Long legs for wading Long necks

114. Order Anseriformes Flat bill Webbed feet

115. Order Falconiformes Hooked bill Talons Eagle Hawk Falcon

116. Order Passeriformes Perching foot Songbirds 5000 species Mocking bird Thrushes Swallows Magpie Crow Starling Jays

117. Order Columbiformes Short neck Short legs Pigeons Doves

118. Order Strigiformes Large eyes Silent flight Nocturnal predator Owls

119. Order Apodiformes Small bird Rapid wingbeat Hummingbirds

120. Fly up, down, left, right, backwards and upside down Wings beat 50 -200 times per second Heart rate =600 bpm Eat 2/3 body weight each day Nectar, pollen & insects

121. Order Galliformes Chicken like Strong beaks Heavy feet Chicken Turkey Pheasants Quail

122. Order Charadriiformes Short bill Strong fliers Shorebirds Gulls

123. Order Psittaciformes Thick tongue Hinged and movable upper beak Bright colors Parrots Parakeets

124. Order Piciformes Two toes forward and two toes backward woodpeckers

126. Order Sphenisciformes Webbed feet Wings as used for swimming penquins