Exam 1 Flashcards
“Pod”
Means foot
True or False: Birds are Amniotes
True
What’s the amnion and what’s its significance
The amnion is a newly derived (evolutionarily) extraembryonic membrane. The amnion is flexible, allows gas exchange, water-proof.
are vertebrates with feathers, modified for flight, and for active metabolism
Birds
what sub category are birds under
Reptiles
what birds have keels
Carinate birds
what birds are non-flying, flat chested
Ratite Birds
What are the extant descendants of the reptilian Archosaurian lineage
- Crocodylians
- Aves
What class are birds in?
Class Aves
How many extant birds are there?
Approximately 10,000
What’s the smallest bird in the world?
Bee hummingbird
What’s the largest bird in the world?
Ostrich
How many species of birds are there in the U.S.?
950
How many species of birds are there in North America
1950
What are the 5 basic characteristics of birds
- Feathers a unique character among living animals, but also found in dinosaurs.
- Endothermic
- Skeleton modified for flight. Bones hollow, forelimbs support the wing, ribs, with uncinate processes, beak but no teeth, reduced tail.
- Breathing by lungs and associated air sacs
- Internal Fertilization and hard-shelled amniotic egg
What are the 2 categories that make birds flying machines
- Weight Reduction
- Power enhancement and adaptations that pertains biomechanics or flight.
What are some ways that birds bodies help them fly faster in terms of weight reduction?
- Reduce weight by the absence of some organs.
- females only have one ovary.
- most birds don’t have a urinary bladder.
- reproductive organs shrink during the non-breeding season.
- carry only as much fat as necessary. they’re typically very lean. - Modern birds are toothless and grind their food in a muscular gizzard near the stomach.
- Birds have a torpedo (fusiform) shape.
- Birds have their center of gravity positioned so as to be aerodynamically stable when flying.
- The skeletons of birds have several adaptations that make them light, flexible, but strong.
- the bones are honeycombed to reduce weight without sacrificing much strength.
What are some ways birds fly faster in terms of power enhancement?
- Flying requires a great expenditure of energy from an active metabolism.
- Birds are endothermic, using their own metabolic heat to maintain a constant body temperature.
- Efficient respiratory and circulatory systems with a four chambered heart keep tissues well supplied with oxygen and nutrients. - Birds have excellent vision and excellent coordination, supported by well-developed areas of the brain.
- The large brains of birds (proportionally larger than those of reptiles or amphibians) support very complex behavior.
What are the most obvious adaptations for flight?
Feathers and wings
What does “ABA Area” mean
American Birding Association
What’s the difference between Modern and non-modern birds?
Modern birds are everything but ratite and tinamous.
What’s the difference between 1. Paleognathae vs. 2. Neognathae
- Paleognathae are modern birds, except they have ancestral archosaurian palate. 5 orders which include Ratites (ostriches, rheas, cassowaries, emus, and kiwis, all with unkeeled sternum); and tinamous (with keeled sternum).
- Neognathae are modern birds with flexible palate- the other 22 orders
- “non passerines”- 26 orders that are not passerines.
- Passerines- the most derived order, the “songbirds”. About half of all species
What’s a ratite?
Background: most birds are carinates because they have a carina, or sternal keel, which anchors the large pectoal muscles.
- carinate birds exhibit a great variety of feather colors, beak and foot shapes, behaviors, and flying styles.
Ratites: These include a few flightless birds, the ratites, which lack a breastbone and large pectoral muscles. Ratites include ostrich, kiwi, and emu.
What’s a Tinamou?
A Tinamous are one of the most ancient groups of bird, members of a South American bird family of about 47 species in 9 genera. Although they look similar to other ground-dwelling birds like quail and grouse, they have no close relatives and are classified as a single family Tinamidae within their own order, the Tinamiformes.
What’s a passeriforme?
- Nearly 60% of living bird species are in the order Passeriformes, or perching birds.
- 2 defining characteristics are:
- perching feet.
- syrinx with special intricate muscles to control singing.
- other major orders that are hawks, eagles, owls, woodpeckers, ducks, geese, herons, and egrets
What are the 10 characteristics of Birds
- Feathers- unique (mostly) and defining
- unique to birds and some extinct dinosaurs
- thermoregulatory function and flight. - Bills
- toothless
- lightweight, composed of Beta keratin
- tremendous - Skeletal specializations
- pneumatic bones (hollow, air-filled bones w/ struts)
- fusion and reduction of bones
- forearms, neck, furcula, thoracic cavity, keel. - Bipedalism
- walk on toes - centralized body mass for flight and balanced walk on land.
- Fusiform body for aerodynamic efficiency
- High metabolism
- endothermic (40-44°C) - Specialized circulatory and respiratory systems
- meet oxygen and fuel demands - Highly developed CNS and vision and hearing; cerebellum highly developed
- Large nutrient-rich eggs.
Why is there such diversity in birds?
- change over time
- millions of years of evolutionary change and adaptation
- change in environmental conditions
- populations adapting to different conditions/tapping into available niches.
What are examples of diversity in form and function of feet?
- Webbing and lobbed- aquatic
- long toes- spread out weight (e.g. heron)
- bracing foot- provides support (e.g. woodpecker)
- covered in feathers - cold environment
- perching foot- primarily arboreal
What’s the first example of adaptive radiation in birds
The classic case study of: Darwin’s Finches that evolved from the basic form to different bills and diets
What’s the second example of bird adaptive radiation?
Hawaiian honeycreepers
What’s the third example of adaptive radiation?
Charadriiformes
What’s the evolution of shared characteristics due to similar ecological pressures not a common ancestor (analogous not homologous).
Convergent evolution
what faunal region is the us
Nearctic
What faunal region do more species live than Nearctic because it’s larger?
Palearctic
Where faunal region do most species live because because there’s more vicariant events?
Neotropical
What faunal region includes New Guinea and lots of species for a small area
Australasian
When did the earth just prior to Archaeopteryx Pangea is breaking apart
150 MYA
when did the Archaeopteryx appear
135 MYA
When did some major orders established: time of shorebirds , few other modern birds. Roughly 10 my before first radiation of modern birds
65 MYA
what does convergence mean?
Unrelated forms fill same ecological niche in 2 regions
what are 3 sets of examples of ORDERS of birds
- Jacamars & Bee-eaters
- Toucans & Hornbills
- Hummingbirds & Sunbirds
What are the 3 time periods relevant to bird evolution
Mesozoic
1. Triassic (245-208 MYA)
2. Jurassic (208-146 MYA)
3. Cretaceous (146-65 MYA)
Who are the major players in the Mesozoic Timeline
- Dinosaurs- Triassic
- Mammals- Triassic
- Birds- Jurassic
- Ammonites become dominant- Jurassic
- Ammonites, Dinosaurs rule all- Cretaceous
- Flowering plants-Cretaceous
What’s the most accepted hypothesis for the end of the Mesozoic
- impact: a big object from space smashed into the Earth, causing mass destruction
-Chixulub: big crater in the Yucutan peninsula of Mexico- appears to be approximately the right age
What are Pterosaurs?
They’re not “true” dinosaurs, and definitely not birds, nor in any way ancestors to birds. They’re own group.
Were dinosaurs “warm-blooded?”
Most were not. But new finds of feathered dinosaurs.
Creates heat from inside
Endothermic
Absorbs heat from outside
Ectothermic
maintains a constant internal temperature
Homeothermic
temperature fluctuates depending on outside conditions
Poikilothermic
