Baleen Whale Migration

Abstract

Baleen whale migration emerges as a foundational theme of cetacean behavioral ecology and the relationships that bind humans and whales together. From facilitating the culmination of the great human migration many centuries ago, to their roles as ecosystem service providers, baleen whales have influenced the path of human history. With a focus on modern technologically enabled insights, we provide an overview of what scientists currently know about the spatial and temporal distribution of baleen whales and their migratory behaviors. Although a coarse model of seasonally paced north–south migration generally applies, a deeper analysis reveals the remarkable diversity of baleen whale migrations. Some species, including gray whales (Eschrichtius robustus), migrate relatively close to shore; others, including humpback whales (Megaptera novaeangliae), tend to migrate across ocean basins. Some species, including Bryde’s whales (Balaenoptera edeni), appear to largely reside in middle to low-latitude ecosystems, relatively removed from cold, high-latitude water. In contrast, bowhead whales (Balaena mysticetus) remain within Arctic ecosystems all year, and others, including Omura’s whales (Balaenoptera omurai), may not migrate at all. The scientific focus to date has largely been on population-specific studies of where whales go, what their behaviors are, and when they undertake their migrations. Thus, there remains much to be learned, particularly regarding why baleen whales migrate and how they navigate during their long-distance migrations. Technological innovations such as satellite tags and passive acoustics have revolutionized our understanding of baleen whale behavioral ecology and ethology, and technology will continue to play a critical role in advancing the science of baleen whale migration.

Paikea is an ancestor of many [Māori] iwi (tribal groups) of the eastern seaboard of Aotearoa New Zealand. The Paikea story is known in other parts of the Pacific and provides an explanation for how this particular ancestor reached Aotearoa from the ancestral and spiritual home-land of Hawaiki. There are several versions of the story, but it is commonly accepted that he was the sole survivor of a marine disaster and through his endeavors reached shore at a place called Ahuahu. This was achieved through the mobilization of his marine ancestors, his family of whales, who helped him reach Aotearoa. Paikea is described as riding on the back of a whale, or transforming into a whale, and is referred to accordingly as he tahito, he tipua, he taniwha, he tohorā, he tangata, he tekoteko—an ancient being, an extraordinary being, a denizen of the deep, a whale, a man, a sentinel for his people. Paikea is also the Māori name for southern humpback whales [i.e. Oceania population of Megaptera novaeangliae].

The Paikea narrative underpins a certain type of relationship with whales, one of kaitiakitanga—care or stewardship. This is conceptualized in whakapapa [i.e. genealogy] terms, whereby whales are identified as ancestors and kin. The kaitiaki [i.e. guardian] relationship underpins voyaging knowledge contained in oral histories. Whales guide waka (canoes/vessels) to land, through dangerous seas and channels, and are called upon to smooth rough waters for safe passage. Ocean-going waka hourua are double-hulled to replicate the physical qualities of a pair of whales cresting waves in tandem.

Tere tohorā, tere tangata—where whales journey, people follow—is a whakataukī (proverb) that encapsulates the essence of this synergy.

Billie Lythberg and Wayne Ngata (Te Aitanga a Hauiti), New Histories of Pacific Whaling, Rachel Carson Center Perspectives, No. 5, pp. 105–106, 2019