Satellite mapping of emperor penguin habitat dispersal under climate extremes

Abstract

Emperor penguins serve as early-warning sentinels for the Antarctic ecosystem and climate change. Understanding how climate change influences their habitat use offers insights into the fragile polar ecosystem for supporting the climate actions under the United Nations Sustainable Development Goals (SDGs). However, it remains unclear how the gradual climate change and extreme climatic events affect the dispersal of emperor penguin breeding habitats due to the lack of a systematic and long-term dataset documenting their habitat use. Here, we first develop guano indices and present an automated approach to map emperor penguin breeding habitats at 30-m spatial resolution using Earth observation satellite imagery, achieving a user accuracy of 94.8 %. We further reveal that habitat dispersal is sensitive to four extreme events—heat, blizzard, storm, and low sea ice. Specifically, colonies exposed to intense climate extremes generally exhibit more fragmented distributions, with habitat reuse periods mostly under 3 years and interannual habitat dispersal exceeding 4 km. These four extreme events together explained 21 %–72 % of the variability in annual habitat dispersal. Under a high-emission scenario driven by fossil fuels, the warming-induced annual fragmentation of habitats is projected to be 255 m greater than that under a low-emission scenario using clean energy, leading to higher vulnerability in emperor penguins by disrupting their ability to survive and reproduce. The proposed method enables routine mapping and updating of emperor penguin breeding habitats, and the associated findings demonstrate that extreme climatic events significantly impact habitat use and dispersal patterns, highlighting the urgent need for global climate policies aligned with sustainable development to protect the Antarctic ecosystem.