The study, which was led by Francesca Pancaldi, used photographic and video evidence to show how a pod of killer whales (Orcinus orca) employed a collaborative approach to target the whale sharks' pelvic area, including the claspers and pelvic fins. This strategy caused significant blood loss and allowed the killer whales access to the sharks’ lipid-rich livers, which is a highly nutritious part of the prey.
Several times a year, squaretail groupers gather at spawning aggregation sites to mate, typically around the new and full moons between December and March. The males show up several days before to establish their territories, while the females arrive a day before the new moon. Then, both groups will attempt to pair and spawn in synchrony with the moon’s cycles.
For this species, these brief encounters are their only opportunities to reproduce.
The study found that dolphins displayed the open-mouthed gesture more frequently during interactions with others than when playing alone. Even more interestingly, they tended to use this gesture when their playmate could see them, suggesting that dolphins are aware of their friends’ attention and adjust their behaviour accordingly.
Conventionally, shark behaviour has been perceived as largely instinctive and uniform across individuals. However, a team of researchers, led by Thomas M. Vignaud, have upended this notion, uncovering a spectrum of individual personalities among bull sharks frequenting feeding sites.
Recent scientific efforts have begun to unravel the complexities of shark behaviour, challenging age-old perceptions, and revealing a world of intelligence and sophistication hidden beneath the waves. Ila France Porcher reports.
Researchers conducted trials using SMART drumlines in New South Wales, Australia, to catch and release sharks, particularly White Sharks. The study aimed to quantify the short-term post-release movements and the longer-term fate of these sharks.
Sharks were caught using SMART drumlines deployed about 500 meters from shore. Once captured, they were quickly secured to a research vessel, minimising potential injuries. The sharks were tagged with satellite-linked radio transmitting tags and acoustic transmitters to monitor their movements post-release.
Elasmobranchs have become lucrative targets with the depletion of traditional fish stocks and the surge in the shark fin trade. Although, in recent decades, much scientific evidence has challenged traditional misconceptions, stereotyped media portrayals persist, and they hinder conservation efforts. So, this special issue was created to highlight the complex behaviour and cognition of sharks and rays.
A comprehensive study published in the journal Marine Mammal Science analysed over 60 years of recorded interactions between Southern Resident killer whales (SRKW) and porpoises in the Salish Sea. This endangered population of orcas, known for their fish-based diet, particularly Chinook salmon, has been involved in numerous incidents of porpoise harassment, leading to the deaths of many porpoises.
The study proposes three main reasons for this behaviour:
We’ve all seen those huge schools of fish that move as one and coordinate their movements so perfectly. New research has come up with a way to map the chain of direct interaction in such schools of fish, discovering that the fish pay attention to one or two of their neighbours at a time when the school moves as a group.
