Diving energetics in king penguins (Aptenodytes patagonicus)

Area of Science:

• Marine Biology
• Animal Physiology
• Avian Ecology

Background:

• King penguins (Aptenodytes patagonicus) are pursuit-diving birds.
• Understanding their dive energetics is crucial for assessing foraging strategies and population dynamics.

Purpose of the Study:

• To determine dive durations and energetic costs of swimming in wild king penguins.
• To estimate the aerobic dive limits (ADL) and oxygen consumption patterns during foraging dives.

Main Methods:

• External data loggers (pressure sensors) recorded dive durations in wild king penguins.
• Respirometry in a swim channel measured energetic costs of swimming at various speeds.
• Calculations estimated oxygen consumption and ADL based on dive and surface intervals.

Main Results:

• King penguin dives were predominantly short (95% < 6 min, 66% < 4 min).
• Minimal transport costs occurred at swimming speeds of 1.8–2.2 m/s.
• Estimated submergence oxygen consumption was low (0.23 ml O2 kg−1 s−1), suggesting an ADL of at least 4.2 min, with surface oxygen uptake significantly higher.

Conclusions:

• King penguins likely conduct most dives within their aerobic capacity.
• Physiological mechanisms for partitioning oxygen consumption between diving and surface periods require further investigation.
• The study provides insights into the energetic constraints and foraging behavior of king penguins.