Scientists have discovered bone fragments in Alaska that suggest birds have been breeding and nesting in the Arctic for over 70 million years. Study author Lauren Wilson of Princeton University made the finding while searching for ancient bird remains in rocks formed around 73 million years ago.
The Prince Creek Formation, a sequence of rocks in northern Alaska, was home to a coastal floodplain at that time. Wilson’s team extracted chunks of ancient soil from thin rock layers during the winter, when temperatures dropped as low as -30°C (-22°F). The extreme conditions made for challenging field work, with Wilson describing it as “the most intense field work I’ve ever done.”
The discovery sheds new light on how birds adapted to thrive in the Arctic environment. Today, around 250 species of birds have evolved to live at the Earth’s poles, with some migrating long distances and others enduring harsh winter conditions. The ancient bone fragments provide a unique glimpse into the region’s history and the origins of these incredible birds.
Source: https://www.newscientist.com/article/2482217-first-evidence-of-ancient-birds-nesting-above-the-arctic-circle