Puffins are seabirds whose diet is crucial to their survival and life cycle. Understanding what they eat and how they hunt provides insight into their adaptations and the challenges they face in a changing marine environment.
Main Food Sources
Puffins primarily consume small fish, which form the staple of their diet. Common fish species include sand eels (also known as sandlance), herring, capelin, and sprats. These fish typically range from 2 to 6 inches (5-15 cm) in length, though puffins can manage fish up to 7 inches (18 cm) long. An adult puffin may need to eat around 40 small fish per day to sustain itself.
When small fish are scarce, puffins supplement their diet with marine invertebrates. These include crustaceans like euphausiids (krill), shrimp, and crabs, as well as mollusks and polychaete worms. These alternative food sources become more important during periods of low fish availability.
How Puffins Hunt for Food
Puffins are skilled underwater hunters, using their wings to propel themselves through the water. Their webbed feet function as rudders, helping them steer efficiently while submerged. They can dive to impressive depths, sometimes reaching 200 feet (60 meters), though they typically forage in shallower waters.
Once a fish is caught, puffins demonstrate a remarkable ability to hold multiple prey items crosswise in their beaks. Specialized backward-pointed spines on the roof of their mouth and a muscular, grooved tongue help secure the fish in place, allowing the puffin to continue hunting for more without losing its existing catch. This adaptation allows them to carry an average of 10 fish at a time, and sometimes even up to 60, back to their nests.
Diet Changes and Specialized Feeding
The puffin’s diet can shift depending on the season and prey availability. Adults may consume a wider variety of prey, including more invertebrates, especially during the non-breeding season. However, during the breeding season, their focus intensely shifts to providing high-energy fish for their rapidly growing chicks, known as pufflings.
Pufflings require a diet rich in protein and fat for proper development, making small, oily fish like sand eels particularly important. The puffin’s ability to carry multiple small fish simultaneously to the nest is crucial for chick nutrition. Parents do not tear up fish for their young, requiring pufflings to swallow them whole.
Food Supply and Puffin Survival
The availability of their primary food sources directly impacts puffin populations. Changes in ocean temperatures, often linked to climate change, can affect the distribution and abundance of key fish species like sand eels. When sand eels or other preferred fish decline, puffins may have to travel further to find food, or switch to less nutritious prey.
Overfishing of forage fish, such as sand eels, also poses a significant threat to puffin survival. A lack of adequate food can lead to reduced breeding success and lower chick survival rates, as young puffins may struggle to swallow larger or less suitable fish, sometimes leading to starvation. These pressures highlight the delicate balance between the puffin’s dietary needs and the health of the marine environment it inhabits.