Researchers based at the University of Canterbury in New Zealand have found that migrating humpback whales achieve navigational precision usually associated with jetliners or arrows.
The findings, published in the Royal Society journal Biology Letters, confirm that humpback whales (Megaptera novaeangliae) can perform straight line movements over thousands of kilometers of open-ocean during the longest documented mammalian migrations.
The research team, led by Dr Travis Horton and Dr Richard Holdaway of the University of Canterbury, showed that humpbacks perform these straight line movements without deviating more than a degree, despite the presence of strong sea-surface currents.
One whale, moving southeast from Brazil towards the South Sandwich Islands, swam over 2200 km during a 28-day period along a heading that varied by less than half a degree, said Dr Horton.
The data come from sixteen whales that were fitted with 30cm-long, satellite-monitored tags during their seasonal migrations away from low latitude calving grounds off Brazil, New Caledonia, and Rarotonga. The tags are attached to the blubber and fall off over time.
Although the research provides unprecedented insights into the spatial precision of whale migrations, it remains a mystery how such movements are achieved.
This research findings are a significant result from an extraordinary team effort intended firstly, to describe the navigational capacities of humpback whales, and secondly, to interpret how these navigational behaviors are performed.
The study advances our understanding of navigational behavior during migration, yet it also raises several questions regarding the external orientation cues used by humpback whales and perhaps other long-distance migrants.