Chapter 15 Part 2

Question 1

What is the range of optimal incubation temperatures?

Answer 1

-Safe temperature range = 35-41 C (95 – 105.8F)
Below 35 and development in greatly slowed
below 26 and the embryo rarely recover

Question 2

How does nest temperature and ambient temperature influence parent behavior?

Answer 2

Example: great tit

• Incubation rhythms of the Great Tit are directly related to the air temperature in the nest box
• Time on the eggs (sessions) decreases and time off the eggs (recesses) increases when the air is warmer

Question 3

Keeping eggs cool

Answer 3

• example: Gray Gull
• birds nesting in hot spaces must keep eggs cool into order to avoid lethality
• Nest in the extreme deserts of northern Chile incubate their eggs at night, when it is cold
• Shade them during the day, when air temperatures reach from 38°C to 39°C

Question 4

How do incubation periods vary?

Answer 4

l ength: ranges from 11-80 (10-100) days

Corresponds to body size:
- Small songbirds have the shortest incubation periods
- Hummingbirds, petrels, albatrosses take much longer than predicted
by BS
- Woodpeckers have very short incubation periods for their body size.
Their young are especially altricial
- Species with precocial young typically have longer incubation
periods

Question 5

Asynchronous incubation

Answer 5

• begin incubation before the clutch is complete – the young hatch at intervals
  Advantages:
• Minimizes time required for the first eggs laid to hatch and fledge (important if predation pressure is high)
• Staggers peak feeding demands of chicks
  (important in environments where food supply is low?

Question 6

Synchronous incubation

Answer 6

• Delay the onset of incubation until the clutch is complete
  Advantages: Important if the parent moves the brood after hatching to some other area for safety or feeding, as in many precocial species
• Ensures that the embryos begin to develop and later hatch at roughly the same time, even though some eggs are laid earlier than others

Question 7

Air cell

Answer 7

• what nestling breaks through to hatch, breaks through the internal shell membrane (starts breathing by using the internal air cell in egg)

Question 8

Egg tooth

Answer 8

• used to break external shell in egg hatching

Question 9

the hatching muscle?

Answer 9

• At the back of neck, provides support needed to break open egg, move neck around to assist

Question 10

What happens to the yolk sac at hatching?

Answer 10

The yolk sac, which will no longer be necessary once the chick escapes the egg, starts to
retract and is absorbed by the newly emerged hatchling

Question 11

In what way are megapodes unique when it comes to incubation and parental care?

Answer 11

• Use heat from decomposing vegetation, geothermal springs, or
  the sun to incubate their eggs
• IMAGE SHOWING VARIOUS ONES LOOKS AT