Avian adaptations

Question 1

Label the image

Answer 1

2-3 metacarpal bones fused
Digits have limited motion
Shoulder is ellipsoid joint so limited motion

Question 2

Describe muscles of bird wing

Answer 2

Large pectorals to adduct shoulder joint to create powerful downstroke

Supracoracoideus (lies deep to pectorals) abducts shoulder joint to create upstroke

Question 3

Describe bird wing shapes

Answer 3

Question 4

Describe penguin adaptations

Answer 4

Flap wings without folding them

Both up & down strokes produce thrust

Short feathers create hydrodynamic surface to reduce friction

Question 5

Describe Gannets, guillemots & murres adaptations

Answer 5

Diving birds that fly underwater

Fold wings at carpus & use inner (humeral) part of wing to generate thrust

Question 6

Describe Cormorants, grebes & loons adaptations

Answer 6

Dive using their webbed feet

Keep wings folded

Question 7

What are some factors that prevent flight

Answer 7

Large body size
Short broad wings
Lack of strong pectoral muscles
Environmental adaptations – availability of food or avoiding predators

Question 8

Describe some avian leg conditions

Answer 8

Tibial dyschondroplasia
Zone of hypertrophied cartilage cells in proximal end of tibiotarsal bone fails to become calcified as blood supply is absent

Rickets
Osteodystrophy due to lack of vitamin D3 or Ca/P imbalance resulting in lack of mineralisation
Long bones soft & pliable

Chondrodystrophy
Insufficient bones produced at cartilaginous growth zone resulting in short bowed bones

Twisted leg
Genetic lateral rotation of distal leg

Hock walking
Heavy birds with collapsed metatarsus

Osteoporosis
Calcium deficient so prone to pathological fractures

Femoral head necrosis
Fast growing birds with staphylococci hip infection