Title: Ornithology
1Ornithology
- Basic Characteristics, Evolution of Birds, Form
and Function,
2Intro/Basic Characteristics
3What are birds?
- Taxonomy
- Kingdom Animalia
- Phylum Chordata
- Class Aves
4Characteristics
- Bipedal
- Feathers (diagnostic)
- Insulation
- Lift and thrust
- Toothless bills covered with horny sheath
- Wings
- Ability to fly
5Characteristics (cont.)
- Adaptations associated with flight
- Skeleton
- Musculature
- Physiology
- Reproductive system
- CNS
- etc
6Adaptive Radiations (within adaptive radiations)
- Evolution of ecological diversity within a
rapidly multiplying lineage (Schluter, 2000) - 150-160 MYA
- gt10,000 species extant
- Fraction of what has existed
7 8Hawaiian Honeycreepers
- Radiations within smaller groups
- Radiation in body parts
9A note on Avian Classification
- Imprint of Linneaus 1758
- Binomial nomenclature
- Upupa epops
- Standard English Names (Common Name)
- In NA, both established by AOU
Kingdom Phylum Class Order From Genus species
species
Genus
10Classification of three species of woodpeckers
Taxon Downy Woodpecker Hairy Woodpecker Northern Flicker
Class Aves Aves Aves
Order Piciformes Piciformes Piciformes
Family Picidae Picidae Picidae
Genus Picoides Picoides Colaptes
Species pubescens villosus auratus
11Current Classification
- 29 orders
- 187 Families
- 2000 Genera
- 10000 species
- Rapidly changing
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13Interesting biogeograpy
- Each faunal region has its characteristic birds
endemics
14Biogeography (cont.)
Regions Endemic (non-passerines) Representative Family Radiation
Holarctic Incl. Nearctic and Palearctic Loons, (Gaviidae) Auks (Alcidae) Accentors (Prunellidae) NW warblers (Parulidae) OW warblers (Sylviidae)
Neotropical Rheas (Rheidae) Sunbittern (Eurypygidae) Motmots (Momotidae) Hummingbirds (Trochilidae) Tyrant-flycatchers (Tyrannidae)
Ethiopian Ostrich (Struthionidae) Turacos (Musophagidae) Woodhoopoes (Phoeniculidae) Larks (Alaudidae) Sunbirds (Nectariniidae)
Oriental None Leafbirds (Irenidae) Pheasants (Phasianidae) Flowerpeckers (Dicaeidae)
Australasian Emus (Dromiceidae) Kiwis (Apterygidae) Monarch-flycatchers (Monarchidae) Birds-of-paradise (Paradisaeidae)
15Biogeography (cont.)
- Most bird communities or faunas are mosaics of
species of various ages from various historical
backgrounds - factors affecting species richness
Immigration / Invasion
Stochastic extinction events
Regional Bird Community
Local Bird Community
Speciation
Habitat selection
Competitive exclusion
From Ricklefs and Miller, 2000
Mass extinction events
Predatory exclusion
161998
17Evolution of Birds
18Note on Phylogenetics
- Phylogenetics History of the evolution of a
group - Cladistics defining groups based on shared
characteristics not found in ancestors (derived) - Cladogram tree-like hypothesis of the
hierarchical evolutionary relationships of a group
A
C
D
E
F
OTUs Tips Nodes Branches Extinct
taxa Speciation Reading the tree
B
time
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20Based on shared, derived characteristics
21middle ear bones
22Diversity of Birds100,000 species!
- - Heritable variation in a population due to
mutation - - Some variation leads to differential
reproductive success (if expressed)
Pg 47
- Due to
- Phyletic evolution
- Cladistic evolution (speciation)
- Extinction termination of a lineage
b
a
c
c
b
c
b
d
b
Time
a
a
a
a
23Shared, derived characters with anything?
24Other features?
- Nucleated RBCs
- Scales
- Ankle in tarsal bones (not between long bones and
tarsals) - Bipedal (theropods)
- Yolked, polar, cleidoic egg
- Females are heterogametic
- etc
25Link Between Birds and Reptiles
- Lots of morphological, behavioral and
physiological similarity between Reptiles and
Birds. - Which reptiles???
26Founding of Archaeopteryx
- Lithograph Quarrymen Jurassic limestone
- Single feather impression 1861, Bavarian Quarry
- Complete skeletal impression Few months later
- 2nd complete skeleton 1877, quarry near
Eichstatt, Germany - Herman von Meyer
- Archaeopteryx lithographica
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29Archaeopteryx
- Debates
- Support of Darwinian evolution
- Darwin predicted transitional fossils in 1859
- one of the best links between two taxa
(Feduccia, Ostrom, etc.) - Creation / Evolution debate (pg 27)
- Evolution of feathers (flight or insulation
first?) - Evolution of homeothermy in birds
- Evolution of flight
- Ground-up vs. Trees down
30Could it fly?
31The historical evolution of flight debate
- Two main hypotheses
- Ground-up (cursorial hypothesis)
- Trees-down (arboreal hypothesis)
32Ground-up
- Assume biped, cursorial ancestor
- Has to be bipedal to use wings at all
- Large legs for running muscle attachment
- Bones of legs are long
- Once running
- Use feathers for other things
- Catch insects
- Pick up minimum speed for lift Flight
33Trees-down
- Assume semi-bipedal leaping and gliding ancestor
- Use of claws to scale trees, then glide to ground
- Claws retained in winged appendages
- Short hand wing (power), relatively long arm wing
(lift) - Claw geometry (Feduccias study)
- Large attachment sites for downstroke on humerus
but no keeled sternum - Flying squirrels?
34Winner?
- Trees-downmaybe
- Largely historical debate
- More productive???
- Why evolve flight?
- To help escape from predators
- To help catch flying or speedy prey
- To help move from place to place (leaping or
gliding) - Vigilence
- Migration, etc
- Nomadism
- To free the hindlegs for use as weapons
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36Craniate phylogeny and diversity of living
species From Bemis http//www.bio.umass.edu/biolog
y/bemis
371/31/06
- Lab tomorrow in the field (Briar Creek Lake)
- Bring
- Clothes
- Binoculars
- Waterproof notebook
- Time to meet?
- Lab Activities BWSV
- Read Taking Field Notes Handout
- Lecture Today
- End Evolution
- Start Form and Function
- Feathers
38Fig. 3.25
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41Fig. 3.20
42Alternative Hypotheses?
43Leading alternative hypotheses
- Theropod Ancestry
- Pros
- Lots of fossils
- Some with feathers
- Bone morphology
- Foot with 3 digits
- Embryology (birds w/5)
- Sholder joint similarity
- Facilitates wings held at sides
- Eggs in nest structure
- Cons
- Theropod adapted for running (how could flyer and
runner share ancestry? - Feathers? (Old argument)
- Theropod fossils yes
- Used for insulation
- Exapted for flight.
- Thecodont Ancestry
- Pros
- Tree dwellers
- Glider forms
- In the trees
- More parsimonious argument that flight feathers
evolved from gliding stabilizers rather than
insulation - Cons
- Fossil Evidence is missing
44Form and Function
45Feathers
- Most conspicuous integumental derivative
- Keratin
- Function
- Flight
- Heat Conservation
- Reduced convective and evaporative heat loss
- Increased insulation
46Feather Development
Lizard scales
Bird scales
- Development triggered by an interaction b/w
epidermis and dermal mesenchyme - Formation of dermal papilla (placode)
- Mitotic divisions in a collar zone of the stratum
germinativum near the base of the papilla form a
crown of barbs - Covered by a horny sheath of epidermis
Scaleless hen
47Feather Development
- As development proceeds
- Differential cell division on one side of the
papilla - Timing of expression of two proteins Shh Bmp2
- These cells form a shaft away from the body
- carrying the barbs that are formed in the collar
- The base of the feather recedes into the skin
- Accompanied by layers of epithelial cells
- Feather follicle
- Degeneration of epidermal sheath
48Feather morphogenesis
49Morphology of a Feather
50Morphology of a feather (cont)
51Morphology of a feather (cont)
- Major Types
- Contour
- Insul., Flight
- Vanes symmetrical
- Vanes asymmetrical
- Semiplumes and
- Rachis gt barbs
- Down
- Rachis lt barbs
- Insul.
- Adult down
- Natal down (lost)
- Powder down
- Grooming
- waterproofing
- Bristles
- Little or no vane
- Filoplume
- Monitor pennaceous feathors
Pennaceous
Plumulaceous
52Contour feathers
53Contour feathers
54Semiplume
55Down
natal
powder
adult
56Filoplume
57Bristles
58Cross-section of feather follicle
- Barb ridges of epithelial
- Surrounding dermal core of connective tissue
- Space of the follicle
- Epithelial tissue of follicle
- Associated musculature
59Melanins
60Carotenoids
61Porphyrins
62Structural colors