Middleton Island is the first thing the wind hits between Hawaii and Alaska. Out here in the Gulf of Alaska, tens of thousands of seabirds gather each summer, turning a remote outpost into one of the most important windows we have into the health of the North Pacific. Seabirds don’t just live on Middleton—they report back. The Black-legged Kittiwakes nesting on the island have shown us, in real time, how rapidly ocean conditions can change. During the 2014 to 2016 marine heatwave, GPS-tracked birds shifted from feeding on capelin just a few kilometers from the island to making long, energy-intensive trips to coastal waters up to 576 kilometers away. From behind one-way mirrored windows in our research tower, we watched their chick production plummet even as their foraging effort soared. When ocean temperatures cooled, the system didn’t simply reset—the birds revealed what may be a new ecological regime.…