First record of exchange between humpback whales in the Strait of Magellan and the Antarctic Peninsula
- Published in: Polar Biology, 2021
- Authors: Jorge Acevedo, Juan Capella, Ted Cheeseman, Cole Monnahan, Ken Southerland, Paola Acuña, Anelio Aguayo-Lobo
- Download the full study here
What was discovered in this study?
For the first time it was documented that some humpback whales (Megaptera novaeangliae) of the Strait of Magellan not only feed in this area, but They can travel as far as the Antarctic Peninsula to feed., breaking the idea that these areas were isolated from each other.
How was the discovery made?
The researchers used two methods:
Photo identification of caudal fins (flukes)
They were compared 187 whales in the Strait of Magellan with 2,553 Antarctic whales through the Happywhale platform.
They were detected 2 exact matches: a male and a female that had been seen in the Strait years before, and then in Antarctica in 2018.
Stable isotope analysis of carbon and nitrogen
They were analyzed 37 skin samples of whales of the Strait.
Two of them showed chemical signals indicating food in Antarctica, suggesting short trips or a change of area.
What does this exchange entail?
Although only 4 cases were recorded, this is a key change in our understanding of the population:
It challenges the idea that the Strait of Magellan hosts a completely independent population.
It could affect the abundance estimation models, which until now assumed zero migration between feeding areas.
Suggests that Some whales may make infrequent interzonal migrations, even within the same season.
How to interpret it?
The exchange rate is very low, which does not substantially change the classification of the Strait as independent subpopulation.
Reinforces the importance of conducting further studies mobility, population structure and eating behavior in southern Chile.
Fidelity to the Strait remains very high, but this finding suggests the existence of transitional groups or explorers.
Whalesound: Providing data to discover the unknown
This discovery was made possible thanks to the collaboration between scientific institutions, the Happywhale database and the field work carried out by Whalesound in the Strait of Magellan.
Our expeditions not only bring people closer to whales, but also contribute essential data for their conservation.
