The ecology of whales in a changing climate

Abstract

The study of whale ecology did not begin until most populations had been depleted by commercial whaling. Some species still teeter on the edge of extinction, whereas others have shown encouraging signs of recovery. The Eastern Pacific population of gray whales (Eschrichtius robustus) was hunted to low levels in the 19th century but was protected from commercial harvest by the International Whaling Commission in 1947. The population then grew to almost 27,000 by 2016 (1), which is near the upper range of estimates of pre-whaling abundance (2). Most population models assume that after this recovery, gray whales would reach a relatively stable equilibrium. On page 207 of this issue, Stewart et al. (3) challenge this assumption by documenting boom-and-bust cycles in abundance, driven by surprisingly large and rapid changes in their food supply over the past three decades.