What are some characteristics of birds? | • Feathers
• Wings
• Bill
• Specialized skeleton
• Hand, head, pelvis, feet
• Centralized body mass
• Endotherms (40-44oC)
• Efficient circulatory and respiratory systems
• Rapid and efficient digestive system
• Advanced nervous system and acute vision
• Reduction in the number of some organs
• Oviparity |
What are the purpose of feathers? | – Support for flight
– Insulation / water-proofing
– Signalling, camouflage |
What is a passerine bird? | Perching bird |
What are 6 keys to identifying birds? | 1. Size & Shape
2. Colour Pattern
3. Field Marks
4. Behaviour
5. Habitat
6. Songs & Calls – not as helpful for all birds |
What are 3 factors that account for difference in plumage within the same species? | Age, sex, and season |
How do most birds moult? What kind of birds are the exception and how do they moult? | One pair of feathers at a time to maintain balance
Waterfowl; they shed feathers all at once |
How do birds navigate when migrating? | • Magnetic compass
• Celestial navigation – Solar + Moon and stars
• Navigation by sight – Topographical landmarks |
Why do birds migrate North? | • Benefits must offset costs
– Day length – longer days to feed / raise young
– Space – 8X more = Less competition + don’t need to wait to breed
– Food – quantity, quality, less exploited
– Fewer predators and parasites |
What are the 4 main flyways birds use to migrate? | • Atlantic
• Mississippi
• Central
• Pacific |
Why do some ducks migrate to moulting areas? | – Abundant food
– Protection from predators |
What are the 2 types of newly hatched birds? | – Precocial
• Covered with down
• Can run, swim or walk when they hatch
• E.g., waterfowl, gamebirds
– Altricial
• Naked and vulnerable
• Remain in the nest
• E.g., raptors, songbirds |
Why is monogamy prevalent in birds? | 1. Both parents required to raise young – Especially altricial young
2. Males can’t monopolize resources required to support extra mates |
In polygynous birds is it more common to have precocial or altricial young? | Precocial |
What are the 3 purposes of courtship displays? | 1. Ensure same species breed together
2. Synchronize reproductive cycles
3. Help partners assess each other |
What is a lek? | An area where males congregate to engage in courtship rituals |
What are the benefits of leks? | Females can compare males
Safer from predators |