Ornithology final

  1. Are feet homologous between birds and theropods?
    No, three main tows in theropods are 1, 2, 3, while birds are 2, 3, 4
  2. Evidence against Archaeopteryx flight
    • Skeleton overall like small theropod 
    • No supracoracoideus 
    • lacked openings in bones for air sacs
  3. Evidence for Archaeopteryx flight
    • Presence of large furcula (other theropods, dromaisaurs, also have fused clavicles but much smaller)
    • Asymmetrical feather vane
    • Remiges arched as in flying birds
    • Placement of longest feathers (wings and tail)
    • enlarged cerebellum
    • enlarged optic and auditory lobes (compared to theropods)
  4. Evidence supporting cursorial origin of flight
    general skeleton like small terrestrial theropods
  5. Evidence against cursorial origin of flight
    • No supracoracoideus
    • gravity
    • pelvic girdle not really cursorial
  6. Evidence in favor of arboreal origin of flight
    • Claw shape on forelimbs
    • claw shape on toes
    • reversed hind toe
  7. Paleozoic Era
    230 to 600 mya (oldest we have to know)
  8. Mesozoic Era
    • 65 to 230 mya
    • Includes Triassic, Jurassic, and Cretaceous
  9. Triassic period
    180 mya
  10. Jurassic Period
    135 mya
  11. Cretaceous Period
    80 mya
  12. Archaeopteryx dating
    160 mya
  13. First mammals
    Triassic
  14. Enantiornithines
    • Reptilian characteristics: skull, teeth, pelvic girdle
    • Avian characteristics: Ribcage/sternum, forelimb, prominent pygostyle
    • No uncinated process
  15. Differences between enantiornithines and modern birds
    • Direction of fusion of metatarsal bones
    • Scapula contains socket
    • supracoracoideus along scapula
    • ectothermic growth rings
  16. Ornithurnes
    waterbirds, eventually went extinct
  17. Skeletal adaptation for flight in birds
    • Bone structure
    • no teeth
    • no bony external tail (in modern birds)
    • fortified body cavity
    • fusion of bones for strength
    • keel on sturnum
  18. Nervous system adaptations for flight in birds
    • Large cerebellum 
    • enlarged optic lobes
  19. Sensory adaptations for flight in birds
    • large size
    • forward orientation
    • receptor cell density (retine 1.5-2x thicker than in other vertebrates)
    • no external ears
    • reduced olfactory apparatus
  20. Muscle adaptations for flight in birds
    • no heavy jaw or face muscles
    • no heavy back muscles
    • huge pectoralis (10-40% of weight)
    • Supracoracoideus
    • High concentration of red muscle fibers
  21. Respiratory system adaptations for flight in birds
    • air-sac system (typically 9 air sacs, 6-12)
    • 1 way flow in lungs
  22. Digestive system
    • Rapid digestion
    • Crop, proventriculus, gizzard
  23. Reproductive adaptations for flight in birds
    • seasonal regression 
    • no live births
    • single ovary (except hawks)
  24. Problems with biological species concept
    • classifying allopatric populations
    • non-monophyletic species
  25. phylogenetic species concept
    • modern version of morphological species concept
    • minimum diagnosable units (super subjective)
    • avoids non-monophyletic species
    • solves problem on classifying allopatric population
  26. Disadvantages of phylogenetic species concept
    • species limit at mercy of N
    • arbitrary definition of diagnosable
    • depends on resolution of data
    • unequal rates of character evolution
    • human perception of "species"
  27. Pre-mating reproductive isolating mechanisms
    • behavioral
    • temporal
    • mechanical (not known in birds)
  28. Oceanic vs continental islands
    an oceanic island arises independently, continental islands were at one point attached to a larger land mass (ex. Britain, Trinidad, etc)
  29. Limiting factors to colonization
    • psychological barriers (crossing water)
    • physical barriers
    • depauperate flora
    • depauperate fauna
    • physiology of long distance migrants (zugunruhe)
    • successful reproduction
    • small population
  30. Empirical trends in oceanic island birds
    • density compensation (high densities, but only a couple of species) due to ecological release
    • greater sexual dimorphism (ER)
    • Longer bills (ER, big bills better because can take larger prey)
    • more generalized habitat 
    • flightlessness
    • loss of anti-predator behaviors
    • differentiation (new selective pressures, genetic drift, founder effect)
    • (adaptive radiation)
  31. Breakdown of mating systems (%)
    • Monogamy- 90%
    • Polygamy- 3% (including polygyandry)
    • Promiscuity- 6% (leks)
  32. Polygyny Threshold
    • territory on x axis, benefit on y
    • point at which it is advantageous for females to mate with an already mated male rather than an unmated male with a very poor territory
    • steeper curves for polygynous (increased differences between territories)
  33. Secondary cavity nesting
    • cannot make own cavity
    • cavities have lower predation rates
  34. Classical polyandry
    • Simultaneous- lay eggs into multiple nests more or less at the same time
    • Sequential- most effort is focused on one male; temporal difference between nests
  35. Cooperative polyandry
    • within the female's territory, there are multiple, often related males.
    • Only one nest
    • typically at least two males copulating, alpha and beta males
    • harris hawk, galapagos hawk
  36. Dispersion pattern
    • often due to food availability
    • the patchier food is, the more likely it is to be leking species
  37. Type A territory
    • "All purpose"
    • usually nearly the same size as home range
    • occupied by a single pair, a harem, or communal group (polygynandrous)
  38. Type B territory
    • "Bum sitting"
    • matings and nest area only
    • MODO
  39. Type C territory
    Colonial (rookeries)
  40. Determinants of territory type
    • Defensibility of food supply
    • availability of nest sites
    • If something is defended, a limited resource is involved.
  41. Type D territory
    • Display
    • mating only, females have type B territories
  42. Mixed-species flocks
    • component species solitary or pairs
    • nuclear species determine foraging route and emit rallying call
  43. proximate vs ultimate causes
    ultimate causes have to do with genetic advantage, proximate causes are usually "how" (physiology)
  44. Advantages to being gregarious
    • Predator avoidance (many-eyes hypothesis, confusion factor/dilution)
    • Food finding efficiency
    • Theoretically, predator component should be more important
  45. Burskirk model
    • Food searching behavior determines --> predator vulnerability, which in determines --> feeding sociality
    • highly vulnerable = gregarious
  46. Cost of flocking
    • Competition 
    • Predator attractionn
    • Foraging rhythm
  47. Ultimate controls of timing of breeding
    Food
  48. Proximate controls of timing of breeding
    • Endogenous rhythm
    • Annual zeitgeber
    • Modifying factors (direct food availability)
  49. Zeitgeber
    Photoperiod --> hypothalamus --> anterios pituitary --> LH, FSH, Prolactin
  50. Endogenous rhythm
    • biological processes which vary seasonally
    • drifts in absence of stimuli; WTSP did not reach reproductive status
  51. Early human impact on birds/ecosystems
    • hunting
    • introduction of mammals (and reptiles) on oceanic islands
    • deforestation 
    • agriculture
  52. Human impact on birds last 200 years
    • 72 species extinct (at least)
    • oceanic islands- 63
    • continents- 9
  53. Causes of extinction
    • Introduced mammals- 2
    • Introduced disease- 20 
    • Introduced snake- 2
    • Human exploitation- 10
    • Habitat destruction- 10
  54. North American extinctions
    • Labrador Duck (1875)
    • Great Auk (1884)
    • Passenger Pigeon (1899)
    • Carolina Parakeet (1938)
    • Ivory-billed Woodpecker (1941)
    • Eskimo Curlew (1963)Bachman's Warbler (1965)
    • California Condor
  55. Burkirk's findings- Solitary birds
    • Terrestrial foragers
    • Hummingbirds
    • Sentinel foragers
  56. Burkirk's findings- Single-species Flocks
    canopy frugivores
  57. Burkirk's findings- Mixed-species flocks
    • Omnivores in canopy
    • Canopy insectivores
  58. Type A territory food/nest
    both even
  59. Type B territory food/nest
    • Food far from nest
    • Nest scattered- not clumped
  60. Type C territory food/nest
    • Food far from nest
    • Nest limited and clumped
  61. Type D territory food/nest
    • Food far from territory, patchy
    • Nest [even]
Author
eeliz1
ID
330909
Card Set
Ornithology final
Description
Ornithology final
Updated