WILD 3580 1st Edition Lecture 28 Outline of Last Lecture I Bird Evolution II Characteristics III Weight reducing adaptations Outline of Current Lecture I Power Promoting Adaptations Current Lecture I Power Promoting Adaptations 1 Endothermy allow high metabolic rates to sustain a power flight Q10 Effect Birds have the highest body temperature of all vertebrates 104 degrees F 40 degrees C Feathers evolved into fur a form of insulation 2 Specialized Flight Muscles Pectoralis down stroke Supracoracoideus up stroke Together these muscles make up to 35 of body weight Keeled sternum provided extra surface area for muscle attachment Flightless birds do not have a keeled sternums Carinate sternum flying birds Ratite sternum lightless birds 3 Circulatory System white meat breast less myoglobin dark meat leg more myoglobin Color depends on amount of myoglobin oxygen binding protein in muscles 4 chambered heart double circulated Birds have the largest heart to body mass ratio Hear rate decreases as body size increases negative relationship Steeper range These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute 4 Respiratory System 20 of body volume 2 lungs 18 air sacs Air Sacs compliment the respiratory system Usually 9 varies from 6 12 No gas exchange in the air sacs just lungs 2 functions 1 Increase oxygen utilization by allowing a one way movement of air takes 2 respiratory cycles one way movement of air more efficient 2 Cooling system moisture surfaces provide evaporative cooling as air is moving in and out of body prevents overheating 5 Aerodynamics and Balance Center of balance is just under the wings Organ placement on both sides for balance 6 Feathers Development Follicle indentation in the skin that the feather grows from o Papilla cells being produced Rachis shaft middle part of the feather Vane portion that has feathers on it o Attached by barbs which contain microstructures Calamus below the vane down to the base of the feather hollow Superior umbilicus hole on top of calamus Inferior umbilicus hole at the end tip of the feather o Umbilicuses were sources of nutrients during development Barbs Central part of the barb is a ramus Barbules o Proximal barbule microstructures on the barb that point towards the body o Distal barbule point away from body Barbicells attached to barbules Hamuli hooklets on distal barbules only
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