NEW YORK (AP) – Marine biologists have documented two individual humpback whales that accomplished singular, unprecedented transoceanic voyages between Australia and Brazil.
These cetaceans were distinguished by their unique caudal fluke patterns, observed at the two geographically distant locales, separated by approximately 9,000 miles (14,500 kilometers).
The whales embarked on journeys in opposing directions, traversing distances further than any previously recorded humpback migration.
“This represents an exceedingly uncommon occurrence, yet it serves as a compelling illustration of the extensive migratory capabilities of these magnificent creatures,” stated Phillip Clapham, a former director of a NOAA whale research initiative, who was not involved in this particular research.
Humpback whales are renowned for their extensive oceanic travels, often adhering to predictable migratory pathways.
These marine mammals typically adhere to migratory routes that are learned from their maternal lineage.
Their feeding behavior involves consumption of krill and small fish during warmer periods, followed by relocation to warmer, tropical waters for breeding throughout the winter months.
The extensive underwater existence of these animals presents considerable challenges in meticulously tracking their movements.
In a recent scientific undertaking, researchers undertook an analysis of an extensive dataset comprising over 19,000 whale photographic records amassed over the past four decades by both professional research entities and the broader public.
Sophisticated recognition algorithms were employed to facilitate the identification of individual whales by scrutinizing the distinct pigmentation and serrated edges of their flukes.
Through this analysis, scientists were able to identify two distinct whales at various breeding grounds situated in eastern Australia and Brazil across different years, inferring that they had completed the extensive journey between these two continents.
One of the humpbacks covered a distance exceeding 9,300 miles (15,000 kilometers).
This substantial migratory span surpasses recorded distances set by previous record-holders, including a humpback that navigated from Colombia to Zanzibar.
Given that the photographic evidence only captures the whales at the commencement and conclusion of their respective journeys, the precise routes undertaken remain elusive to researchers.
The unusual nature of these intercontinental migrations, as humpbacks typically do not traverse between distinct breeding sites, leaves the motivations behind these two individual journeys undetermined at this juncture.
It is posited that they might have encountered conspecifics at shared feeding grounds and subsequently diverged from their typical migratory patterns, rather than returning to their point of origin, as suggested by study co-author Stephanie Stack of the Pacific Whale Foundation via email.
“The discovery of not one, but two individuals that have migrated between Australia and Brazil prompts a re-evaluation of our existing understanding regarding the separation between these distinct humpback populations,” Stack remarked.
Such extended oceanic odysseys are notably more arduous for whales inhabiting the Northern Hemisphere, where the presence of extensive continental landmasses complicates inter-oceanic travel.
Scientific consensus suggests that these record-breaking migratory feats underscore the remarkable peripatetic capabilities of humpback whales.
Furthermore, these tracking methodologies offer a valuable means of monitoring whale populations amidst the escalating challenges posed by climate change, which is leading to warmer ocean temperatures that could potentially alter the distribution of krill and, consequently, influence humpback feeding and breeding grounds.
The comprehensive findings of this research were officially disseminated on Tuesday within the pages of the esteemed journal Royal Society Open Science.
