Case Study: King Penguins

Adapted from Lewden et al. 2020

Why is using thermal imagery is useful in understanding penguin behavior?

An infrared camera can calculate the surface temperature of everything in the frame. The camera does this by using the radiation emitted by objects. It's important to note that it can only observe surface temperatures, and not the core temperatures of large mammals. You can learn more about how thermal cameras work on our Science page.

The Results

Thermal images of a fully hypothermic king penguin flipper and chest (representing its core) as it rewarms after its return from the sea. At the upper left, you can see the time since it left the sea, the average flipper temperature, and the average chest temperature.

Q7: How do the temperatures of the flipper and chest differ at the beginning?

Q8: What is the last part of the penguin's body to warm? Why do you think this is?


Mean (with standard error bars) temperature of king penguin flippers, as a function of time on land. Fully hypothermic birds are represented by filled squares and solid lines; partially hypothermic birds are represented by light squares and dashed lines.
(Note: Edited from original by removal of wild-colony and year-one lines.)

Q9: What differences do you notice between the fully and partially hypothermic populations?

The researchers found a 5-minute delay to flipper warming in fully hypothermic penguins. There is no delay to flipper warming in partially hypothermic penguins. Why might that be? One possibility is that core temperature warming took precedence over flipper warming. Researchers think that the hypothermic penguins continued to vasoconstrict their flippers to focus on raising their core (chest) temperature during the first 5 minutes represented in the graph. Then, once their core temperature was back to normal, they ended vasoconstriction to allow their flippers to begin warming.

Q10: Consider why king penguins would have adapted to warm up this way. What are the benefits of regaining a normal core temperature before regaining flipper temperature?

Penguins are also facing the cold, strong polar winds.

Q2: Imagine you're on a windy beach with a group of friends. What might you do to stay warmer?

Along with their thick feathers, emperor penguins use huddling to warm themselves up!

Q3: How would huddling help penguins stay warm?

By pressing together, they reduce how exposed they are to cold air, which reduces the amount of heat carried away via thermal convection. They also block themselves from wind, which can accelerate heat being carried away during convection. Some penguins are on the outside of the huddle, which means they take the brunt of the wind.