Questions from Quizzes

Question 1

During winter, Black-capped chickadees exhibit “nocturnal hypothermia.” Describe what this phenomenon is and explain how this capacity works to help these birds survive the winter in Alaska.

Answer 1

• VERY WELL INSULATED! Feather structure is different on northern BCCH than others. (preliminary data suggests more barbules). This creates more loft (more insulative value).
• Birds also have more control of feathers then mammals do with fur.
• Dropping the core temperature (10°C) reduces the temperature difference between the chickadee and the environment - which lowers the rate of heat loss according to the Fourier’s equation Q =kA (Tb –Ta)/d

Question 2

What does the latent heat of evaporation refer to?

Answer 2

Amount of energy required to convert 1 g of liquid to gas (at its boiling point)

Question 3

Describe and explain the energetic consequences for a wolf eating a caribou “on the hoof” versus gorging on a frozen winter-killed caribou

Answer 3

• Frozen caribou requires energy from specific and latent heat of water

Question 4

What does the Coriolis Effect refer to?

Answer 4

• Refers to the deflection of sun/light on the air masses.
• The primary factor governing the movement of the world’s ocean currents and air movements

Question 5

What is the concept explaining the relative abundance of (terrestrial) herbivores compared to carnivores?

Answer 5

• The 2nd law of thermodynamics states that during any transfer of energy, some is dispersed and becomes unusable.
• Thus, available energy will decrease with each trophic level.
• Herbivores has food readily available for them

Question 6

Calculate the half-life of a decomposing batch of leaf litter that has a decomposition constant (k) of 0.35.

Answer 6

• M_t= M₀e^-kt
  
  • ln(0.5)=0.35t
  • t=0.69/0.35
  • ≈2