The Antarctic minke whale, a socially flexible species
A recent study shows that Antarctic minke whales are capable of socializing in certain situations. This discovery was made thanks to detection beacons and video and audio recorders installed on some twenty subjects.
Within the Antarctic ecosystem, they are the major predators of krill, and also a species about which little is known. Thanks to a study carried out by a team of American-Australian researchers, we finally know more about the social and feeding behaviors of Antarctic minke whales.
Scientists from Griffith University in Australia and the University of Santa Cruz in California have conducted one of the first quantitative studies of the social structure and feeding habits of these iconic Antarctic cetaceans. “Key predators of krill, such as the Antarctic minke whale […], play an essential role in the fragile Antarctic sea ice ecosystem,” reads the study, published on May 25 in the journal Behavioral Ecology and Sociobiology. “They are an abundant krill specialist, but their ecological role in the Antarctic remains poorly understood due to their cryptic behavior and remote habitat. It is therefore crucial to develop a baseline understanding of their basic social and foraging ecology.”
One of the first discoveries made by the researchers was that Antarctic minke whales have a social structure with fission-fusion dynamics. This type of structure is typical of animal species, which come together in certain circumstances (to feed or sleep) before separating, often into sub-groups, leading to a constantly evolving social composition. It is often found in terrestrial and marine mammals and, thanks to this study, we can now establish that Antarctic minke whales exhibit this kind of social dynamic in the same way as other baleen whale species.
In fact, in 60% of cases, scientists observed that this species of whale formed short-term associations, both in the search for food and in other activities.
The researchers also observed that larger individuals were more inclined to socialize than smaller (and often younger) subjects, reducing their foraging efforts and associating, in at least twelve cases, in groups of two or three individuals. But that’s not all. Observations also showed that diving behaviors were synchronized, suggesting that these animals use group foraging strategies. A behavior previously underestimated in this species.
To reach these conclusions, the research team equipped 28 Antarctic minke whales with animal-borne camera tags. This process has made it possible to measure the diving, foraging and social behavior of the cetaceans. The study took place in 2018 and 2019 in Andvord and Paradise bays, in the western part of the Antarctic Peninsula.
“These findings provide essential baseline information on the sociality and group foraging behaviors of Antarctic minke whales,” mentions Dr. Jenny A. Allen, researcher and lead author of the study in a press release issued on May 27 by Griffith University. “Understanding these patterns is crucial, especially as climate change continues to impact the Antarctic ecosystem.” In a rapidly warming environment, understanding the relationship between Antarctic species is indeed a crucial subject.
Mirjana Binggeli, Polar Journal AG
More on the subject
