Avian Bio

Konrad Lorenz (Nobel 1973)

Study of animal behavior : instinctive behavior (imprinting), behavior is triggered by environment, importance of understanding context of behavior.

Niko Tinbergen (Nobel 1973)

Causation of behavior, rules of external stimuli for releasing innate behavior (bird silhouette), four questions of ecology.

Christiaan Eijkman (Nobel 1929)

Role of vitamin B (source of thiamine → glucose metabolism) from studies of chickens.

Peyton Rous (Nobel 1966)

Cancer is transmissible through viruses, from studies of chickens.

Dry cell

How much space the cell is taking. Larger genome = more space taken up in the cell = more room for mitochondria.

Bird genome

Most conserved genomes evolutionarily, studies using birds have shown a lot about which genes do what

Bmp4

Gene important for craniofacial development.

Avian paleontology

Birds as models for understanding dinosaurs/alligators (parental care)

Biomimickry

Mimicking biological organisms

Bioinspiration

Getting ideas from biological organisms

Avian engineering applications:

Used as models to observe flight mechanics, dynamic grasping and perching in arboreal environments (robotic application)

“Ecological barometers” (sensitive to environmental conditions)

Birds of prey are specifically susceptible to pollutants (weakens eggs)

Ex) canary in the coal mine.

Bio accumulation

Gradual build up of substances, such as toxic chemicals, inside a living organism over time.

Bio magnification

The process where the concentration of toxic substances increases in living tissue as the chemicals move up the food chain.

Avian ecosystem services

Consume insects, (carrion: scavenging dead animals), pest control, carcass dispose, seed dispersal, fertilizer, pollen nation.

Prum et al. (2015)

390 Kb of data (genomic) from 189 species

Case study: Morphology vs. Molecules

Can tell different stories about how groups are related, even biogeographic logic can mislead because it changes. Ex) evolution of ratites and flightlessness.

Archosaur

Group containing crocs, pterosaurs, dinos, and birds

Archosaur closet living relatives

Crocodiles and alligators

Archosaur extinct relatives

Other dinosaurs ← theropods, maniraptora

Avialae

Birds and bird-like theropods more closely related to birds than non-avian theropods. (Sister to Dienonychosauria, velociraptors and nonavian)

Crown group birds

Contains living present representatives and share a common ancestor

How are birds related to dinosaurs?

Nucleated red blood cells, scales on legs and face

Vane

Rachis

Calamus

Barbs

Barbules

Barb

Epidermal

Central rachis

Tail

Wing

Semi-plume

Contour

Down

Filoplume

Briselle

Microstructure of feathers

B-keratin is primary structural protein (unique to birds) includes rachis, barbs, and hooklets

Plumulaceous barbs

Unstructured, soft, and fluffy. Lack hooklets and traps warm air next to birds body.

Pennaceous barbs

Flight feathers, vane with smooth, flat 2D surface. Have hooklets

Follicles

Epidermis-lined pits in skin. Double walled columns of epidermis with a dermal core

Progression of feather growth

Helical growth proceeds from epidermal collar and leads to formation of central rachis. Later sheath deteriorates and barbs unfurl

Functions of feathers

Social advertising, thermo regulation, camouflage, protection

Pterylae

Feather tracts (regions of follicles)

Apteria

Bare skin between feather tracts

Down feathers

Fluffy, lack a rachis. Used for insulation (loose barbs trap warm air)

Types of down feathers

Natal - nestlings

Body - adult

Powder - waterproofing

Contour feathers

Major outer feathers that cover a birds body helping to create its smooth shape. Rachis is longer than the barbs

Contour feather (streamlining)

Give the bird an aerodynamic shape to reduce drag

Contour feathers (thermoregulation)

Helps maintain a good body temperature by heating and cooling down

Contour feathers (waterproofing)

Spacing of barbs/barbules and natural waxy oils. Causes water drops to form

Flight feathers - Remiges

Wing feathers

Primaries: attached to manis (hand)

Secondaries: attached to ulna (arm bone)

Flight feathers - Rectrices

Tail feathers attached to pygostyle (tail bone)

Flight feathers - Semiplumes

Intermediate between contour and down feathers, help with insulation

Flight feathers - Filoplumes

Smallest types of feathers, bare rachis. Serve sensory functions to monitor movement of feather code.

Flight feathers - Bristles

Specialized sensory function and protection. Ex) Rictal (face) bristles of flycatchers protect their eyes