AVES

Question 1

Amniota

Answer 1

is the lineage with this reproductive pattern – nonavian reptiles, birds, mammals

Question 2

Aves

Answer 2

• Phylum: Chordata
• Subphylum: Vertebrata
• Class: Aves
• 10,500 species
• 40 orders

Question 3

Living birds (Neonithes) Are Divided Into Two Groups…

Answer 3

• Paleognathae (old jaw)
• Neognathae (new jaw)

Question 4

Paleognathae (old jaw)

Answer 4

• are large, flightless, ostrichlike birds and kiwis

Question 5

Neognathae (new jaw)

Answer 5

• are all other birds

Question 6

Structures All Birds Have

Answer 6

• Feathers
• Forelimbs modified as wings, although not all can fly
• All birds have hindlimbs adapted for walking, swimming or perching
• All birds have keratinized beaks.
• All birds lay eggs

Question 7

Mosaic Evolution

Answer 7

• Evolutionary Change in one or more body parts without simultaneous changes in other parts eg. evolution of birds from dinosaurs.

Question 8

Contour Feathers

Answer 8

• Consist of hollow quill (calamus) emerging from skin follicle and a shaft (rachis) bearing numerous barbs
• Up to several hundred barbs are arranged to form a flat, webbed surface, the vane
• Each barb resembles a miniature feather Numerous parallel filaments (barbules) spread laterally
• Barbules from two neighboring barbs overlap and zip together with tiny hooks
• When separated, they are zipped back together by preening

Question 9

Pneumatized bones:

Answer 9

pneumatized bones, light but strong
* Total weight of a bird’s feathers may outweigh skeleton
* Pigeon skull: 0.21% of body weight
* Rat skull: 1.25% of body weight
Pneumatized bones:
- Stiffened cross-struts and air spaces replace bone marrow
- Thin walls
- Remarkably light and strong.

Question 10

Central Pattern Generator

Answer 10

A neural circuit (or single neuron) that generates a behaviourally significant pattern of motor output in space and time without requiring temporally patterned sensory input

Question 11

How Is Flight Patterns Controlled?

Answer 11

i) Peripheral control
ii) Central Control

Question 12

The Musculoskeletal System of Birds - Legs

Answer 12

• Main leg muscle mass is in thigh with connections by long tendons to feet and toes
• This places main muscle mass near a bird’s center of gravity
• Feet are nearly devoid of muscles
• Toe-locking mechanism prevents a perching bird from
  falling off a branch while asleep

Question 13

Pectoralis Muscle

Answer 13

• Depress the wing in flight and are attached to the sternum keel

Question 14

Supracoracoideus Muscle

Answer 14

• Raises the wing, is also attached to the sternum keel * Lays under the pectoralis muscles
• Pulls the wing up from below by way of a “rope-and- pulley” type of arrangement

Question 15

Four Basic Forms of Bird Wings: 1) Elliptical Wings

Answer 15

Birds that must maneuver in forested habitats have elliptical wings

Question 16

Wing Slots (2 kinds)

Answer 16

Stalling (e.g. during sharp turns, low-speed flight, and frequent landing and takeoff) can be delayed or prevented by wing slots
- Alula
- Gaps between primary feathers

Question 17

Alula

Answer 17

• group of small feathers on the thumb which provides a midwing slot

Question 18

Gaps between primary feathers

Answer 18

• which create wing- tip slots

Question 19

Four Basic Forms Of Bird Wings: 2) High-Speed Wings

Answer 19

• Birds that feed during flight or make long migrations have high speed wings.
• wings sweep back and taper to a slender tip, reduces turbulence.

Question 20

Four Basic Forms of Bird Wings: 3) Active Soaring Wings

Answer 20

• Albatrosses, gannets and other oceanic soaring birds have wings with long, narrow wings
• The high-aspect ratio of long, narrow wings lack wing slots and allow high speed, high lift and dynamic soaring

Question 21

Four Basic Forms of Bird Wings: 4) Passive Soaring Wings

Answer 21

• Vultures, hawks, eagles, owls and other birds of prey that carry heavy loads have wings with slotting, alulas and pronounced degree of curvature