Migration

Question 1

Describe migration

Answer 1

• strategy to avoid cold
• always involves weather and resources
• migrate to similar habitat types

Question 2

Migration Routes

Answer 2

Northern hemisphere - most birds migrate north in spring and south in the fall. At both day and night

Question 3

When to leave? How to get there?

Answer 3

• changing in day length (photoperiod)
• Environmental and innate cues
• visuals (landmarks)
• senses of time and direction

Question 4

Energy constraints with migration

Answer 4

• need to build up energy reserves prior to migration
• may have to put off breeding if resources are scarce
• Longer distance migrants may double body mass

Question 5

Types of feet

Answer 5

Anisodactyl - most common
Zygodactyl - 2nd most common in perching birds
Syndactyl - 2nd and 3rd digits partly fused
Lobate - edged with lobes of skin
Palmate - Anterior digits are webbed
Totipalmate - all 4 toes are webbed
Semipalmate - partly webbed
Raptorial - killer

Question 6

Amniotic egg

Answer 6

• shelled egg with amnion allows development away from water
• Yolk - source of energy
• Allantois - gas exchange, waste storage
• Charion - surrounds embryo

Question 7

Male reproductive system

Answer 7

• internal testes
• internal fertilization
• enlarge significantly during breeding
• Vas deferens stores sperm
• lacks a penis

Question 8

Female reproductive tract

Answer 8

• Only left ovary develop
• fertilization in upper oviduct
• shell added in uterus by shell gland
• egg pigmentation added (blood and bile)
• ovary volume increases 1000x

Question 9

Incubation

Answer 9

• commences when heat is applied to eggs
• may not start until last egg is layed
• precocial - mature
• altricial - helpless