ECCB 302 Verts Lec exam 3

Major groups of Craniata

Characteristics of Amniotes (and which taxa are amniotes)

• amniotic eggs

• impermeable skin

• costal ventilation of lungs

• temporal fenestration

• Turtles, lepidosaurs, archosaurs, mammals

be aware of geologic time scale (periods of mesozoic, timing of this era, and the periods, major events)

aw hell nah bruh

characteristics of Archosaurs

• Antorbital fenestra

• shape of the orbit

• teeth

• bipedalism

• fourth trochanter (nub on the bone)

characteristics of Crocodilians

Arose in triassic

• Nostrils on tip of snout

• Secondary palate separates mouth from nasal passage

• Flap of tissue at base of tongue can seal mouth and throat from water

• Depressor mandibulae is a short and weak muscle that opens a crocodilian’s mouth

• Ventricular septum in the heart

how does Crocodilian heart differ from turtles and lepidosaurs?

they have a 4 chambered heart

be aware of groups of dinosaurs (major groups and groups within each)

bruhhhh

Saurischia

“Lizard-Hipped”

• bipedal

Sauropodomorpha, Theropodomorpha, Coelurosaurs

Ornithischia

“Bird-Hipped“

• bipedal

• probably had cheeks and horny beaks rather than teeth at front of mouth

3 groups: Thyreophora, Ornithopoda, Marginocephalia

Cretaceous-Paleogene (KT) Boundary

66mya

Major Events:

• Extensive mountain building (Rockies pushed up for the 2 nd time)

• Inland seas drying up

• Flowering plant radiation and 2nd insect radiation

• General blossoming of life (mammals just taking off), but then an asteriod impact

• Massive extinctions from dust cloud darkening of Earth

Permo-Triassic Crisis

99% of life was wiped

Cretaceous

145-65 mya

Jurassic

205-145 mya

Triassic

250-205 mya

Mesozoic ERA

250-65 mya (age of reptiles)

Archosauria - origin and when did they take off?

Originated in Permian period but took off in Mesozoic

Diapsida- evolved in ______ period

Carboniferous period of Paleozoic Era— 300mya+

Tetrapoda

largest subdivision of Sarcopterygii

• pectoral girdle separated from skull

• has zygapophysis on vertebrae

• limbs with phalanges

• pelvic girdle attached to vertebral column

Sarcopterygii

27,000 extant species

• 1st appeared in early Devonian period and still persist

• good fossils bc presence of dermal bone and endochondral bone

Characteristics of Coelurosaurs (When did they live? What did they look like? What characteristics did they share with birds?)

Cretaceous

• Were small and used hands or feet

• Furcula, fused bony sternum, egg brooding posture, sleeping posture, T. rex proteins

Characteristics of Dromeosaurs (When did they live? What did they look like?)

Cretaceous

• Small

• Large toe and claw, 2nd digit

• Feet similar to birds

• Remarkable tail structure

• Used fore feet to seize prey

Characteristics of Pterosaurs (When did they live? What did they look like? How did they differ from modern birds?)

Triassic

• Box 16-3 —whatever that means????

• Flight mechanically demanding

• Wing different than birds

also are quadrupedal

Shared characteristics between theropods and birds

• hollow, pneumatic bones

• s-shaped neck

• tridactyl foot

• posture

Hypotheses for the origin of flight

2 hypotheses

• Arboreal or “from the trees down”

• Terrestrial or “from the ground up”

  • arm and wrist movements seem to be consistent with prey seizing

  • feathered forelimbs seem poorly suited for climbing

  • arms used to aid in balance while running, then evolved to short flights

Examples of extinct “birds”

Teratornis- closely related to new world vultures

What class do birds belong to?

Aves

Time periods that major radiations were/are present

you tell me

Feathers – how did they evolve? Know the differences (and the importance of these differences) between filamentous feathers, symmetrical vane, and asymmetrical vane

evil

Archaeopteryx

• asymmetrical vaned wing and tail feathers

• longer arms

• reduced tail

Microraptor characteristics

gliders not flyers

• thats all the info.

• feathers on legs and arms

Jeholornis

Early Cretaceous

• Bird-like wings, thorax, skull

• dinosaur tail

• teeth

• short, rounded wings

Confuciusornis

Early Cretaceous

• crow sized

• elongated tail feathers

• several species

• fish-eating

• toothless beak

• pygostyle

Enanthiornithines

• Metatarsals fused differently + different articulation between scapula and coracoid as compared to modern birds

• Teeth

• Small to medium sized (nothing super-sized)

• Ecologically diverse (how could we know this? fossil record)

why is morphology generally constrained in birds?

Remarkable uniformity in the morphology of birds, mostly as the result of the specializations for flight

composition of feathers

-Composed of a specific type of beta keratin

-Calamus anchors feather to the skin

-Rachis

-Barbs

-Barbules

Contour feathers

• Remiges – wing feathers

• Rectrices – tail feathers

Semiplumes

long rachis with plumulaceous vanes

Down

entirely plumulaceous and rachis is shorter than the longest barb or absent

Bristles

stiff rachis and barbs only at the base or absent

Filoplumes

fine hairlike feather with few short barbs at the tip, used for sensory

bone fusions

Know some of the “modern” birds that have gone extinct, how some of those extinctions were caused, and the effect some of those extinctions on other organisms

• Passenger Pigeon –was thought to be the most abundant bird in the world, went extinct in 1914

• Dodo

• Moas hunted to extinction

• Hawaiian birds due to malaria

Know the 2 major suborders of birds and examples of their constituents

Palaeognathae - Tinamous and Ratites

Neognathae- Galliformes and Anseriformes

Importance of phylogenetic placement of tinamous and ratites

Traditional views: Thought that Ratites monophyletic

• Tinamous are nested inside Ratites

• Ratites are not monophyletic

• Evolution of “flightlessness”

• Biogeographic implications

Know any Orders (and the common names of these Orders) shown in slides

oh my god

Know if any of these Orders belong to “land birds”, “super fliers”, “water bird”, “shore bird”

Know phylogenetic placement of:

Palaeognathae, Neognathae, Galliformes, Anseriformes, Neoaves, and landbirds

wing stuff?????

Avian bones are…

Pneumatic, air filled

Function of feathers

Insulation, flight, ornamental/sexual signaling

Muscle fiber/metabolic differences (depending on biology of the bird, where would you expect to find muscles with a lot of myoglobin?)

• Muscle fiber types and metabolic pathways

• Dark Meat: high capacity for aerobic metabolism; myoglobin

• White Meat: less sustained capacity for aerobic metabolism

• Strong fliers: breast muscles with high aerobic metabolic capacities, but this varies by flight “strategy”

Which wing feathers (specifically) are responsible for flight?

Wing function as an airfoil and propeller

• Primaries propel, secondaries lift

In general, how do birds fly?

What is the function of the alula?

providing lift and preventing stall during slow flight and high angle maneuvers like landing

What is wing loading?

ratio of birds’s body mass to its total wing surface area

Know which muscles are important for flight, and function of each muscle

-Downward stroke of the wings produces thrust (generated with primaries)

-Major muscles involved with flight

1) Pectoralis major – pulls wing down

2) Supracoracoideus – lifts wing

Understand differences in wing proportions relative to type of flight

-Flight muscles account for 25-35% of the total body mass of strong fliers

-Predatory birds, limb muscles 10% (flight muscles ~20%)

-Swimming birds, even distribution of limb and flight muscles

What are the 4 major wing shapes and how do they differ from one another? Know an example of a bird with each major wing shape.

What are the 4 main types of flight?

1. Gliding - simple, wings locked with no wing beat. distance traveled a function of 3 items

2. Flapping - most common form of flight

3. Soaring - dynamic and static

4. Hovering

• not mutually exclusive and more than one type can be used per species

Understand respiratory and circulatory system of birds

respiration:

• 7 air sacs

• no residual volume (air) in lungs

• air sacs poorly vascularized, modifications in lungs to help pick up O2

bird circulation

circulation:

• separate systemic and pulmonary of the heart

• division via a permanent septum between ventricles

• permanent ventricle allows higher rates of flows associated with higher overall metabolism in birds

Understand how and why endothermy evolved in birds

• Air exchange and sustained locomotion/activity produces heat and a substantial amount of energy lost as heat

• Body forms and posture changes to better deal with increased activity

• Temperature regulation via ectothermy or endothermy

• For endothermy to evolve, need insulation and high metabolic rate

• Feathers –insulation, but can be moved to enhance air flow across the body to facilitate cooling

Bird hind limbs

perching- anisodactyl

hopping, walking, running- hallux lost/almost completely lost (emus)

climbing- zygodactyl

surface swimming- palmate feet/lobate/totipalmate (ducks)

diving/underwater swimming- posterior leg position (grebes)

bird tongues

beak types

Bird feet

Be able to explain and define aspects of the bird digestive system

No teeth, gastric apparatus helps process food that would normally occur in the mouth

• ceca breaks stuff down in birds with lower quality diet

Know the major senses of birds and details of each sense: Vision

Most important sense for birds

• different eye shapes are a function of fitting large eye in small skull

• No eyelids - nictitating membrane provides blink

• pecten in back of eye- might help provide extra O2 to eye

Know the major senses of birds and details of each sense: Hearing

Most birds hear the same amount as humans

• Owl are exception bc facial disk that acts as a parabolic sound reflector

• owls also have asymmetry in the shape of the disk of the skull

Know the major senses of birds and details of each sense: Olfaction

Most birds have a poor developed sense of smell

• kiwi and vultures are a few exceptions

Myoglobin

a protein in dark meat- high capacity for aerobic metabolism; myoglobin

lift

-Lift: vertical force equal to or greater than weight of bird

Drag

Resistance- force that is opposed to forward motion and wing movement

aspect ratio

Length : Width of wings

Know the visual and auditory ways that birds communicate with each other

-Color often important in social interactions

-Postures

-Vocalizations

-Male vs female coloration and sexual selection

-Truth in advertising

What is “Truth in Advertising”?

visual signals that correlate with quality of male (health, parasite load, ability to evade predators)

What is a birdsong? Who sings and how are songs learned?

• Bird songs are specifically the breeding calls of many bird species

• Learned behavior

• Males only

• Regional dialects; individual variation

Know the definitions of the various mating systems birds can exhibit

Monogamy (Greek mono = one, gamy = marriage)

Polygamy (Greek poly = many)

• Males (polygyny)

• Females (polyandry)

• both sexes (Promiscuity)

Extra Pair copulations

What is the difference between social and genetic monogamy?

Social Monogamy - Share responsibility for clutch but have extra-pair copulations (contrast to genetic monogamy)

Genetic Monogamy- An exclusive reproductive strategy where a pair only reproduces with each other, meaning all offspring in a brood or litter share the exact same two genetic parents. (like life long mates?)

What are the advantages for extra-pair copulations and social monogamy?

increases fitness and genetic diversity, benefits to both sexes

Know the different types of polygamy

• Males (polygyny)

• Females (polyandry)

• both sexes (Promiscuity)

Why are birds oviparous? (know good and bad hypotheses)

1) Constraints due to flight

2) Ancestral condition

3) Endothermy and retention of eggs in the oviduct - best explanation

Know some details about bird eggs and nests

• nests- structure built to protect eggs and/or young from abiotic and biotic stress

• range from shallow holes to enormous structures in trees

• most species nest individually

do birds have environmental sex determination?

no, they’re like humans

Why are there variations in clutch size?

• nutrition, energy differences in species?

• not all eggs will make it so greater number will ensure some survive

• some lay 1 some lay hella

What are different ways birds can incubate their eggs?

body heat, sun, rotting vegetation, some wait for all eggs to be laid to incubate them- ensures they all hatch at the same time

What are the differences between altricial and precocial young?

Altricial - Naked and dependent on parents (ex:robins)

Precocial- self sufficient (ex: chickens)

What are the advantages of migration?

Advantages: food resources, avoid temperature stress, longer days—generally translates to larger broods being possible compared to tropical species that do not migrate = higher fitness

Disadvantages: Mortality rates high during migration, requires energy

What cues do birds use to orient and migrate?

Preparation: Zugdisposition, Zugstimmung

Timing: Day length and internal rhythms

Navigation and Orientation: sun, Earth’s magnetic field, light, odors, landmarks, sounds

Extra-pair copulations

when an individual that has a social pair-bond mates with an outside individual of that primary pair