A great marvel of the animal kingdom, the Arctic Tern (Sterna paradisaea), makes the longest known migration of any animal on Earth. This small, delicate bird, known for its black-capped head, sharp red beak, and elegant flight, travels an astounding distance of approximately 25,000 miles or more each year. It completes this incredible journey as it migrates from its Arctic breeding grounds to the Antarctic and back again.
A Life on the Wing
Why does the Arctic Tern undertake such an ambitious journey? The answer lies in its unyielding pursuit of daylight and abundance of food. Being a creature of the Polar Regions, the Arctic Tern has evolved to maximize its exposure to the constant daylight of the summer months. It breeds in the Arctic during the Northern Hemisphere’s summer, then migrates to the Antarctic for the Southern Hemisphere’s summer, thereby living in near perpetual sunlight. This strategy not only provides the tern with a relatively stable and favorable climate but also an abundant supply of food.
The Incredible Journey
The Arctic Tern’s migration is a feat of endurance and navigation. Despite its small size, it travels from pole to pole, experiencing two summers and nearly continuous daylight. The journey involves crossing a range of climates, navigating both open sea and coastlines, and dealing with an array of predators and weather conditions.
One would assume the Arctic Tern takes the most direct route for such a long journey, but tracking studies have shown otherwise. Their migration is not a straight path. Instead, they follow a zigzagging route, taking advantage of prevailing wind systems, which saves them energy and makes their epic journey possible.
Survival and Future
Arctic Terns are long-lived birds, with many reaching 30 years of age. This means some Arctic Terns will fly the equivalent of three trips to the moon and back over their lifetime.
Like many creatures of the Polar Regions, Arctic Terns face uncertainties due to climate change. The diminishing polar ice and shifting wind patterns pose challenges to their long-established migration routes and breeding grounds. Understanding the Arctic Tern’s journey is not just a fascinating glimpse into an amazing natural phenomenon, but it’s also essential for its future conservation.
FAQs about the Arctic Tern:
- How does the Arctic Tern navigate? While the exact mechanisms are still not fully understood, it’s believed Arctic Terns use a combination of the sun’s position, the Earth’s magnetic field, and visual landmarks to navigate during their migration.
- What do Arctic Terns eat? They primarily feed on a diet of small fish and invertebrates. Their diet can change based on their location and the season.
- When do Arctic Terns start their migration? Arctic Terns begin their migration journey in late summer. Chicks born in the summer start their first migration only a few months after hatching.
- Where do Arctic Terns nest? Arctic Terns nest in open ground, often on islands and coastal areas in the high Arctic. They are known for their aggressive defense of their nesting area, often diving at intruders to scare them away.
- Are Arctic Terns endangered? Arctic Terns are not considered endangered but their populations are believed to be in decline. Threats include climate change, overfishing, and habitat loss.
Understanding the Arctic Tern’s extraordinary journey brings greater appreciation for this incredible bird and highlights the intricate balance of the global ecosystem, in which each creature, no matter how small, plays a vital part.