Scientists report that a humpback whale has undertaken one of the longest and most extraordinary migrations ever documented, a journey that may be influenced by climate change.
In 2017, a notable sighting occurred in the Pacific Ocean off the coast of Colombia. Years later, the same entity reemerged near Zanzibar in the Indian Ocean, covering a remarkable distance of at least 13,000 kilometres.
This remarkable journey could be attributed to climate change affecting food supplies or a quest for mating opportunities.
According to Ekaterina Kalashnikova from the Tanzania Cetaceans Program, the achievement is “awe-inspiring and unusual even for this highly migratory species.”
The image below captures the same whale photographed in 2022 near the coast of Zanzibar.
Dr Kalashnikova stated that it is highly probable this marks the longest distance ever documented for a humpback whale’s journey.
Humpback whales inhabit every ocean across the globe. These mammals embark on extensive journeys yearly, showcasing one of the longest migrations in the animal kingdom as they navigate their tropical breeding habitats to nutrient-rich feeding areas in calmer waters.
This male’s journey was remarkable, encompassing two far-flung breeding grounds.
One theory suggests climate change impacts the availability of the tiny, shrimp-like krill that humpback whales rely on for sustenance, compelling these majestic creatures to journey greater distances in search of nourishment.
Whales could be venturing into new breeding grounds, a possibility linked to the resurgence of their populations due to worldwide conservation initiatives.
“The precise reasons remain unclear, but potential factors include global climate changes, an increase in extreme environmental events, and the evolutionary mechanisms of various species,” stated Dr. Kalashnikova.
A male humpback whale was spotted among a group captured in 2013 photographs taken from a research vessel off the Pacific coast of Colombia.
In 2017, he was located in a comparable region, followed by another sighting off the coast of Zanzibar in 2022.
According to scientists, the sightings are divided by a great-circle distance of 13,046 kilometres, representing the minimum distance for the route the whale may have traversed. However, the actual distance is expected to be significantly greater.
The earth’s spherical shape means that the most direct route between any two locations is represented by the great circle distance, an arc that connects the two points on the sphere’s surface.
The research is grounded in an extensive collection of hundreds of thousands of whale photographs from researchers, whale enthusiasts, and the general public through the citizen science platform happywhale.com.
An innovative database employs artificial intelligence to identify the unique shapes and patterns of humpback whale tails, or flukes, facilitating the mapping of their movements across the globe.
The findings have been released in the journal Royal Society Open Science.
