Study Sheet Exam 1 Questions Flashcards
What are some of the unique characteristics of birds?
Feathers
Beak/Bill (toothless)
Syrinx
What are some characteristics of birds that are not exclusive?
2-legged, bipedal vertebrate
Gizzards
Wings
Flight
Lay eggs
Endothermic
What traits do birds have that evolved for flight?
• Lightweight, (mostly) hollow bones
• Fusion in hand bones, head,pelvis, feet (lightening and strengthing skeleton)
• Furcula (Wishbone)
• Uncinate Processes
• Carpometacarpus
• Tibiotarus
• Tarsometatarsus
•Keeled sternum in birds that can fly (muscle attachment)
Summarize the importance of the Furcula
The furcula, or wishbone, compresses and rebounds like a powerful spring in rhythm to the beat of the wings. The wing itself is a highly modified forelimb that, with a few remarkable exceptions, is nearly incapable of functions other than flight.
Summarize the importance of the Uncinate Process
Horizontal, backward-curved projections—called uncinate processes—on the ribs overlap other ribs and so strengthen the walls of the body.
Summarize the importance of the Carpometacarpus
fused hand bones, supports and maneuvers the large and powerful primary flight feathers.
Explain Adaptive Radiation and give an example of traits that show this
A phenomenon where great diversity develops due to the evolution of various species adapting to different ecologies and behaviors
Examples:
Beak sizes and shapes
Leg length
Wing shape
Summarize the importance of the Nasofrontal Hinge
Allows for the ability to flex or bend the upper half of the bill. ( Cranial kinesis )
Summarize the importance of the Trabeculae
Complex system of bone struts
Summarize the importance of the Rhamphotheca
Horny sheath covering the jaws ( may have sharp cutting edges)
What are some areas of greatest diversity in birds? Give some examples for each.
Tropical Andes of South America
What is natural selection?
is the differential survival of individual organisms with advantageous traits.
(If the traits are heritable, then survivial will result in adaptive evolutionary change among generations.
Well adapted individuals live longer and produce more offspring.)
What is convergent evolution? Give an example.
the independent evolution of similar adaptations in unrelated organisms
Penguins and Auks ….
What is biogeography?
is the study of the geographical distributions of plants and animals. For more than a century, biogeographers have divided Earth into six major faunal regions corresponding roughly to the major continental areas.
What are endemic species? Give an example.
Each faunal region has its characteristic birds: so-called endemic taxa or species, which are found nowhere else, and other birds that represent major adaptive radiations of more widespread taxa.
What are avifaunas?
regional assemblages of bird species—are mixtures of species of varied ages and origins
List out some of the shared characteristics between birds and reptiles.
• Scales
• Lay eggs
• Skull of both articulate with the 1st neck vertebrae by means of a single ball and socket device- the Occipital Condyle
• Simple middle ear with/ one ear bone - the Stapes
•Ankle is located in the middle of the tarsal bones (foot)
What are archosaurs? What are their defining traits?
are a specific group of reptiles that include alligators and crocodiles, dinosaurs, and pterosaurs
• Distinctive hole in side of skull, in front of eye socket, called antorbital fenestra
• Advanced parental care behavior
Which reptile did birds originate from?
Archaeopteryx lithographica
What are vanes? Why are they characteristic in Archeopteryx?
the planar surfaces of feathers, on either side of the feather shaft
Archeopteryx’s primary (flight) feathers had asymmetrical vanes.
Most modern birds that fly have asymmetrical vanes, especially strong fliers
What is a phylogenetic tree?
is a diagram that depicts evolutionary relationships (a phylogeny) among organisms
• Branches represent historic species evolving through time
•Nodes are points where branches split off, indicating a speciation event producing new lineages
• Clades represent all descendents (living or extinct) with a common ancestor.
What do clades represent?
Represent all dependents (living or extinct) w/ a common ancestor
Which of these are clades? Which are not? Why?
Green and blue are clades because…
Red and orange are not clades because…
What are homologs? Give an example.
Similarities inherited from a common ancestor
Examples:
Wings of all birds are homologs
What is the pygostyle?
a special bone created by a fusion of the vertebrae at the tip of the tail (important for flight)
What are therapods?
The phylogenetic sister group to the sauropods are the bipedal, meat-eating dinosaurs called theropods, which include the famous Allosaurus, Tyrannosaurus rex, Oviraptor, and Velociraptor. Birds are living theropod dinosaurs that are most closely related to the dromaeosaurs like Deinonychus and Velociraptor and to Troodon (see Figure 2–4).
What visual evidence do we have of feathers in therapods?
Archaeopteryx lithographica - 1877: Feathered reptile found fossilized in ancient coastal lagoon in Germany
What are the shared characteristics of birds and Archaeopteryx?
the earliest known fossil bird
1877: Feathered reptile found fossilized in ancient coastal lagoon in Germany
Crow-sized, bipedal reptile with tiny reptilian teeth and bony tail, but also had feathers on wings and tail with a backwards pointing toe called a Hallux.
Archeopteryx’s primary (flight) feathers had asymmetrical vanes.
Vanes are the planar surfaces of feathers, on either side of the feather shaft.
Most modern birds that fly have asymmetrical vanes, especially strong fliers
Did feathers originate with flight?
No
What are the two basic theories of flight?
Arboreal (Gliding)
Cursorial (Running)
What is systematics? How is this done?
The investigation of evolutionary relationships among organisms.
This is done by examining:
• Fossils
•Preserved Specimens
•Behavior
•Genetic DNA
What does taxonomic classification do?
It provides the framework for understanding the evolution of behavior, ecology and morphology
What is taxonomy?
The science of naming and classifying organism according to standardized rules
What is a taxon?
Any group of animals that is recognized in a classification
What does binomial nomenclature include?
Genus, specific epithet, authority
What is a scientific name?
Genus and species
What are hierarchies?
Nested sets of groups with increasingly closer relationships
What were hierarchies originally based on, and what are they based on now?
Hierarchies were first based on superficial traits, such as aquatic versus terrestrial.
Charles Darwin’s Theory of Evolution changed this into hierarchies based on common ancestries.
What does monophyletic mean?
Descending from a single common ancestor
What are morphological traits?
shared anatomical features as a result of common ancestry
What are conservative characters?
traits that don’t easily change in the course of ecological adaptation
What are the 5 different toe arrangements? Draw and give an example for each.
What is a genome? Are they larger or smaller in birds?
the complete set of genetic material of an organism.
We know avian genomes are smaller than mammal and other reptile genomes. Fossilized bone cells show evidence of this trend in genome reduction in archosaurs and dinosaurs as well.
What are the different ways a species can be characterized?
size
shape
song
colors
ecological niches
geographical ranges
What is the Biological Species Concept?
states, “Species are groups of interbreeding natural populations that are reproductively isolated from other such groups”. The criteria in the definition of biological species are the reproductive compatibility of individual organisms and the potential for the genetic exchange between two populations.
What is the Phylogenetic Species Concept?
Based more on ancestry
What is the Evolutionary Species Concept?
What is speciation? Why does it occur?
Speciation is a process that occurs through the division of one species into two or more descendent species as a result of the genetic divergence of isolated populations.
Speciation typically occurs due to geographic isolation (also called Allopatric Speciation).
Describe the process of allopatric speciation.
geographic isolation leads to reproductive isolation
What is the function of feathers?
• Insulation for controlling body temperature.
• Aerodynamic power for flight.
•Colors for communication and camouflage.
What do modified feathers aid in?
• Swimming
• Sound production/hearing
• Protection
• Cleanliness
• Water repellency
• Tactile sensation
What is beta-keratin? What does it make up?
Beta-keratin is a fibrous protein polymer that forms strong, microscopic filaments.
Beta-keratins make up most of hard structures of reptilian skin, and leg scales, claws, and beaks of birds.
Feathers are a special class of beta-keratins with a small deletion in their molecular sequence.
What are the different types of feathers?
Contour Feathers (a typical body feather)
Together, contour feathers make up the outline, or contour, of the body.
Flight Feathers
Wing feathers (Remiges/sing. remex)
Tail feathers (Rectrices/sing. rectrix)
Asymmetrical vanes, with leading edge vane narrower than trailing vane.
Little importance in insulation
What do contour feathers do?
Together, contour feathers make up the outline, or contour, of the body
importance in insulation
What are the different types of flight feathers?
Wing feathers (Remiges/sing. remex)
Tail feathers (Rectrices/sing. rectrix)
What do flight feathers do?
Aid in flight by (control, steering, breaking)
How do you read primary and secondary flight feathers?
What do down feathers do?
soft and fluffy (no vanes– barbs and barbules extend loosely from rachis).
Provide lightweight, thermal insulation and water repellency.
What is the kind of down found on chicks?
Natal down grows from the same follicles that will later grow contour feathers.
(Adult down feathers grow from specific follicles.)
What do filoplumes do?
are a distinct class of hairlike feathers that function in sensing movement and position of adjacent vaned feathers.
What do bristles do?
Specialized feathers with both sensory and protective functions
Consist of a single stiff rachis with a few basal barbs
Have sensory corpuscles around their follicles
What does powderdown do?
special feathers that produce dust-like beta-keratin particles that resemble talcum powder.
Grow in dense, distinct patches (usually under the wings) in herons, doves, some parrots.
As they preen, the oily powder is dispersed over entire plumage
Waterproofing, defense against parasites, luster?
What is molt?
Periods of feather replacement in a comprehensive and a controlled way
What are the two ways molts can happen?
With age: natal down→juvenal plumage
With seasons: all birds have at least one complete molt each year, typically after breeding season, called basic plumage.
What is alternate plumage?
Many birds have evolved a second molt, often occurring in time for breeding season.
How is color produced in feathers?
What colors do melanins produce?
produce black, grey, brown plumage colors.
2 types: Eumelanin (black/gray) and phenomelanin (brown, rufous, tan)
What colors do carotenoids produce?
produce yellow, orange, red, and purple plumage colors.
Non-pigmented cells produce white.
What do structural colors result from?
result from the physical, optical interactions between light and feather nanostructures.
Pigmentary AND Structural mechanisms often function together to produce new colors.
With the exception of albinos and a few all-white species, almost all birds have melanin pigment in their feathers.
What are melanocytes?
are mobile pigment cells that creep about in the dermal layer of the skin.
They manufacture pigment organelles called melanosomes. Melanosomes contain long chains of melanin molecules, which are incorporated into the beta-keratin of immature feather cells.
What are melanosomes?
pigment organelles which contain long chains of melanin molecules, which are incorporated into the beta-keratin of immature feather cells.
What do melanosomes do?
Melanosome dispersal within the feather during feather development is responsible for pigmentation patterns such as:
spots
dots
stripes
scales
Melanosomes also make feather keratin more resistant to wear and tear and resistant to keratin-eating bacteria.
What is the difference between pterylae and apteria?
Rather, feather attachments are densely grouped in particular areas called feather tracts, or pterylae, that are separated by regions of skin with few or no contour feathers, called apteria.
What is the difference between depressor muscles and erector muscles?
Contraction of Depressor muscles moves/rotates feathers downward.
Contraction of Erector muscles rotates feathers upward.
Why do birds preen their feathers?
using beaks, toes to maintain feather vanes and to fight ectoparasites (mites, lice) and bacteria.
What is the preen gland called?
uropygial gland
What is allopreening?
Many species participate in allopreening, preening mates or other social partners.
What are the reasons for bold vs cryptic coloring in birds?
What is counter-shading? Why would this be useful?
Dark coloration top of body and light coloration on the bottom this cause a loss of 3D effect
What is sexual dimorphism? Why would this be advantageous?
Plumage that varies based on sex
Typically evolves by sexual selection for ornamental plumage (usually males)
Conspecific communication
What is forward thrust? Why is it important in birds?
Forward thrust is the forward component of lift.
Thrust is created by rotating the wing forward during the downstroke.
What is soaring or gliding flight?
Simplest form of flight
Air is moving over a stationary wing
What do flight strokes consist of?
produce lift and consist of:
Downstroke (powerstroke)
Upstroke (recovery stroke)
Explain asymmetrical flight stroke
Produces lift and thrust on downstroke and minimizes forces produced on the upstroke.
What are the two main types of intermittent flight? Why would this be advantageous?
Two main types:
Flapping several times and then gliding with wings open. Also called flap gliding.
Flapping and bounding, with wings folded in. Also called flap bounding.
Both reduce a bird’s power cost
What is wing area?
Total surface area of a wing (cm²)
What is wing loading?
relation between body mass and wing area
What is aspect ratio? Differentiate high vs low.
The distance from tip-to-tip of the open wing divided by total wing area
High-Aspect Ratio wings are very pointed
Low-Aspect Ratio wings are wide and rounded
Why are some birds flightless?
Predator-free Islands
Permanent food sources in close proximity
+
High cost of flying (energetically)
= Reduced investment in material and energy for flight
Explain the evolutionary loss of flight in ostriches.
Extremely Large Body Sizes and Herbivory
→Diet of low quality vegetation can favor evolution of large body size, which results is loss of flight capability.
Explain the evolutionary loss of flight in penguins
Specialized Diving Birds evolved powerful legs and feet to function as paddles. This evolution may cause wing and pectoral development to regress
What are the two principle flight muscles?
1)Pectoralis Major: Bring the wings down
2) Pectoralis minor (aka Supracoracoideus): Bring the wings up
What is the difference between red and white meat?
White:
Found in grouse, quail, pheasants, chickens, etc.
• These species do not undertake long flights short bursts of speed.
•White breast muscle fibers contain the carbohydrate glycogen, source of energy for short bursts of speed.
Red:
Found in long distant migrants: e.g., ducks & geese, shorebirds & passerines.
• Muscle fibers appear dark or red because they contain a greater concentration of blood capillaries.
• The principal source of energy in this type of muscle is fat (provides enough energy for long, sustained flights).
