Glacier Finch Builds Nests in Ice and Hatches Eggs in the Cold

When we think of glaciers, polar bears and penguins often come to mind. Finches are more associated with backyards than icy ledges, but one species found a way to survive one of Earth’s most extreme environments. The White-Winged Diuca Finch resides high up in glacial crevices, laying eggs that hatch inside these warm nests. This YouTube video shows rare footage of the birds at roughly 19,000 feet. Their fight for survival is never-ending, and this is how they overcome threats to their nesting ground.

An Unexpected Nest Discovery

The Diuca speculifera, also known as the glacier finch, nests in the glaciers of South America. It’s native to Argentina, Peru, Bolivia, and Chile. The bird’s origins make its nesting habits even more miraculous.In stark contrast to the high-altitude grasslands, this bird prefers to lay eggs in a completely different location. In 2008, nests were discovered by geoscientist Douglas Hardy. The nests were found roughly 19,000 feet above ground, tucked away in small ice caves within the glacier. It was an accidental discovery, as Hardy had been studying the effects of climate change on Peru’s Quelccaya Ice Cap. Hardy’s son, Spencer, helped identify the birds that created the nests. Their findings were published in the Wilson Journal of Ornithology, where the glacier finch became the world’s only bird species known to nest in such conditions.

The biggest question experts had was “why?” For a species that does well in a tropical biome, traveling to a harsh region to lay eggs seems more risky than rewarding. At this altitude, the oxygen present in the air decreases by 50%. It’s viciously cold, with temperatures dropping to -10 degrees Fahrenheit. The breeding season for glacier finches is from April to May, when Peru’s glaciers are still experiencing bitterly cold winds. Despite all of this, glacier finches continue to fly as high as they can, raising the next generation of birds.

Why Glaciers Make Such Good Nurseries

For those who don’t live in Arctic environments, nesting in such a cold place seems extreme. In reality, glacier finches are merely seeking the safest location to raise their young. The exact science behind building igloos applies to the small caves in which these finches build their nests. The glacier itself is cold, unrelenting, and unforgiving. However, a crevice filled with branches, leaves, and underbrush serves as a toasty home. The same ice that chills the environment also serves as a foundation for building a warm shelter—a unique adaptation discovered by glacier finches.

In short, laying eggs at 19,000 feet on a glacier ensures the species’ survival. At this height, predators are rare. The nests of glacier finches are sheltered from the elements, offering protection from harsh weather and natural disasters. Unlike tree nests, the ice provides structural support, natural camouflage, and protection from predators and environmental threats to newly laid eggs. Experts have also drawn connections between the dampness of the glacier and the humidity in their native tropical climate. Inside these ice caverns, the damp air helps prevent the eggs from overheating.

The Survival of Glacier Finches

One key to the glacier finch’s survival is its ability to generate body heat. Hatchlings stay close to their parents until they’re ready to flee the nest. In BBC’s rare footage of a glacier finch nest, two hatchlings prepare to leave for the first time. The climate in the Andes is harsh, even by the standards of native species, which adds to the dramatic nesting choice of the glacier finch. For a short time, adult finches feed their young until they mature enough to take flight. This window is brief, and the melting glacial ice shortens it even further. As the glacier begins to melt, the nest becomes unstable and may collapse, forcing the hatchlings to leave.

Today, climate change is causing glaciers to melt at an unprecedented rate. This has drastic effects on many species, including the glacier finch. As their nesting grounds disappear, these birds also face threats to their feeding grounds. Without a home to lay eggs or food to feed their hatchlings, the species will likely be threatened. It’s estimated that the Quelccaya Ice Cap will continue losing roughly one meter per year. The Quelccaya Ice Cap is a significant nesting ground for glacier finches, but its melting also has another adverse effect. As the glacier melts, water runoff impacts the wetlands at its base. This is also where glacier finches find building materials for their nests. While these birds currently call the glacier home, their future existence is uncertain.

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