Puffins are distinctive seabirds, recognized for their colorful bills and somewhat clumsy waddle on land. These captivating birds spend most of their lives at sea, returning to coastal areas primarily for their breeding season. Their annual migration to establish colonies on rocky islands and cliff tops signals a period of intense activity focused on raising the next generation.
One Egg: A Puffin’s Reproductive Strategy
Atlantic Puffins (Fratercula arctica) lay only one egg per breeding season. This single-egg clutch is an evolutionary strategy, reflecting the significant energetic investment required to successfully raise offspring. Concentrating parental efforts on a single individual maximizes that chick’s survival chances.
Raising a puffin chick demands substantial resources from both parents. The incubation period for a puffin egg lasts approximately 36 to 45 days, with both parents taking turns. Following hatching, the chick, known as a puffling, requires extensive parental care, including a diet rich in small fish. This investment increases its likelihood of reaching fledging weight and surviving its first few months at sea.
The availability of food, particularly small, nutritious fish like sandlance, herring, and capelin, directly influences breeding success. When food sources are scarce, chick growth can be prolonged, and survival chances may decrease. Laying a single egg ensures parents can dedicate maximum effort to providing the best conditions for that one chick, even when environmental conditions are challenging.
Nesting and Chick Rearing
Puffins create their nests in burrows, which they dig into the soft soil of cliff tops or among rocks on islands. Both the male and female puffin collaborate in excavating these burrows, using their bills to loosen earth and their feet to clear debris. These burrows, often 70 to 110 cm long, provide a secure, sheltered environment for the egg and subsequent chick, protecting them from predators and harsh weather.
Once the single egg is laid, both parents share incubation duties. After hatching, the puffling remains in the burrow, relying entirely on its parents for food. Both adult puffins tirelessly forage, carrying multiple small fish back to the burrow in their specialized bills to feed their growing chick.
The chick typically stays in the burrow for about 38 to 44 days, developing rapidly on its fish diet until it reaches nearly adult size. Once ready, the young puffin usually leaves the burrow at night to avoid predators, making its way to the sea where it will spend its initial years before returning to breed.