Arctic Tern Chick vs Polar Bear | Seasonal Wonderlands | BBC Earth

Summary

In late July, the Arctic welcomes the end of Svalbard's summer as the Arctic terns complete the longest animal migration from Antarctica, a 30,000 km journey. Their chicks, hatched just weeks prior, must prepare for the return flight in 21 days. The rich waters of Svalbard provide ample energy, but the chicks' vulnerability on land attracts the Arctic's largest predator, the polar bear, now forced ashore by retreating ice. The terns' fierce defense against the starving bear, despite their size, highlights the resilience of these smallest birds in the face of the Arctic's harshest season.

Takeaways

• 🌏 The Arctic tern undertakes the longest migration of any animal, traveling over 30,000 kilometers from Antarctica to the Arctic.
• 🕊️ The tern's chicks hatch just in time for the short summer season in the Arctic, with only 21 days to grow and prepare for their return journey.
• 🕒 The tern parents must feed their chicks continuously, as the chicks need to gain enough strength to complete the 30,000 km flight back to Antarctica within three weeks.
• 🐟 The abundance of rich waters in the Arctic provides the necessary energy for the terns, which they transport from the ocean to their chicks.
• 🏠 The terns nest on the ground, making their chicks vulnerable to predators, especially when the parents are away fishing.
• 🐻 The retreating sea ice forces polar bears onto land, increasing the risk for ground-nesting birds like the terns.
• 🦅 The Arctic terns are highly aggressive and fearless, capable of driving away larger predators like polar bears, even though they are much smaller.
• 🩸 The terns' repeated attacks on the polar bear can draw blood from its sensitive nose, demonstrating their tenacity.
• 🌊 The retreating sea ice is a significant factor affecting the lives of both the terns and the polar bears, impacting their habitats and food sources.
• 🥶 Polar bears lose weight rapidly when on land, as they are forced to scavenge and struggle to find enough food, highlighting the challenges they face due to environmental changes.
• 🌌 The Arctic summer is a critical time for both the terns and polar bears, as it is a period of intense activity and survival strategies for these species.

Q & A

What time of year is it in the script?

It is late July, the last of Sart's summer.

What is the longest migration of any animal, as mentioned in the script?

The longest migration is over 30,000 kilometers, undertaken by the Arctic terns from Antarctica to the Arctic.

How long do Arctic tern chicks have to prepare for their first migration?

Arctic tern chicks have only 21 days to prepare for their first 30,000 km migration.

What makes the waters of Spal Bir super rich?

The waters of Spal Bir are super rich in energy, which is required by the Arctic terns for their migration.

Why do the adult Arctic terns have to fish nonstop?

The adult Arctic terns have to fish nonstop to transport the energy from the ocean to their beaks for their chicks.

What makes the Arctic tern's nesting ground vulnerable?

The Arctic terns nest on the ground, which makes them vulnerable due to the presence of predators.

Which predator is forced onto the land due to retreating sea ice?

The polar bear, which is the Arctic's largest predator, is forced onto the land due to the retreating sea ice.

How much body weight does a polar bear lose for each day spent on land?

A polar bear loses a kilo of body weight for every day it spends on land.

What does the polar bear turn into when it is on land and starving?

The polar bear turns into a scavenger when it is on land and starving.

What happens when the Arctic tern chicks cry for help?

When the Arctic tern chicks cry for help, their cries are heard and they engage in repeated attacks, drawing blood from the polar bear's sensitive nose.

How are the Arctic terns described in terms of their behavior towards predators?

The Arctic terns are described as highly aggressive, fearless, and capable of driving away the Arctic's top predator.