A humpback whale has undertaken one of the longest and most extraordinary migrations ever recorded, with scientists suggesting climate change may be a key factor behind this behavior.
First sighted in the Pacific Ocean near Colombia in 2017, the same whale was later observed off Zanzibar in the Indian Ocean in 2022, covering an estimated 13,000 km journey.
Researchers believe this remarkable trek could be due to climate change reducing food availability or a long journey in search of a mate. Ekaterina Kalashnikova from the Tanzania Cetaceans Program described the migration as "truly impressive and unusual, even for a species known for long migrations."
Kalashnikova further suggested that this is likely the longest distance ever recorded for a humpback whale's journey. Known for their extensive annual migrations, humpback whales typically travel between tropical breeding areas and colder feeding regions. However, this male's journey stands out because it involved two distinctly separated breeding grounds.
Possible Causes of the Migration
One hypothesis is that climate change is diminishing the availability of krill, the primary food source for humpback whales, compelling them to traverse greater distances to find sustenance. Another theory posits that as humpback populations recover due to conservation efforts, whales may be exploring new breeding territories.
While the exact reasons remain uncertain, Dr. Kalashnikova notes that global climate changes, extreme environmental events, and evolutionary factors may all play roles in driving such exceptional migrations.
The Whale’s Journey
The whale was initially photographed in 2013 during a research mission off Colombia’s Pacific coast and observed again in the same area in 2017. Five years later, it was identified off Zanzibar’s coast in the Indian Ocean. These sightings represent a minimum great-circle distance of 13,046 km, though the actual distance traveled is likely even greater.
Scientists use the concept of great-circle distance, which represents the shortest arc between two points on a spherical surface, to estimate such journeys.
Tracking Whales Through Citizen Science
This groundbreaking discovery was made possible by a vast database of photos contributed by researchers, whale watchers, and the public through the citizen science platform Happywhale.com. The platform employs artificial intelligence to identify individual humpback whales based on the unique shapes and patterns on their tails, known as flukes, to track their global movements.
The findings, published in the journal Royal Society Open Science, highlight the utility of technology and public participation in advancing marine research.
To learn more about these majestic creatures, check out The Secrets of Antarctica’s Giants on BBC iPlayer.
