ANS 42 Lecture Notes - Lecture 10: Wing Loading, Trumpeter Swan, Air Sacs
13 Jan 2017
School
Department
Course
Professor
Avian – Form and Function
1. Archaeopteryx
a. Link between reptiles and birds
b. could have possibly had teeth, a long tail and a hand
i. Also had feathers and furcular: fused clavicles (wishbone)
c. Opposable digits for grasping its perches
d. Nearest living reptile is a crocodile
2. Flight
a. Influenced by:
i. Drag: opposition to air flowing around
ii. Lift: force to keep the body in the air
iii. Thrust: power needed to counteract drag and maintain lift
iv. Wing Loading: body weight divided by the surface area of the wing
1. As body weight increases, wing loading increases
2. In order to flap, need more surface area
3. More surface area need more muscle
a. Heaviest flapping bird is the trumpeter swan
b. 36 pounds, body weight, surface area, and wing loading max out
4. Traits that are from the flying birds are still retained in the birds that
cannot fly
b. Flapping flight
i. Sparrows flap to get a lift
c. Need 55-70% more energy for flight
i. A lot more air that goes through the bird
ii. Moves its ribcage with its flapping flight
1. Allows the air to go into their lungs
2. Some reptiles drop their mouth to allow more oxygen in their lungs
3. Homogenous in structure
a. 9000 living species of birds
4. Adaptations for flight
a. General strategies to decrease body weight
i. Makes them more aerodynamic
ii. Very thin skin with little fat insulation
1. Do’t need because they have feathers
iii. Skeleton
1. Decreased number of bones
2. Thinner bones
3. Hollow but strutted (look at feb. 6 handout)
4. Pneumatic bones: air bones
a. Bones filled with air sacs
b. Air sacs part of the respiratory system
iv. Lack bladder
1. Do’t eed to store urine
2. Excrete waste at will – difficult to house train
find more resources at oneclass.com
find more resources at oneclass.com
