An “incredibly rare encounter” was caught on camera of a pod of dolphins killing an infant dolphin calf in Cardigan Bay last week.
Described as a deliberate act of interspecific infanticide, the footage shows the adult dolphins chasing the calf before repeatedly throwing the infant into the air.
Caught on camera by Sea Watch Foundation (SWF) intern Dylan Coundley-Hughes, he described it as a “remarkable and heartbreaking thing to witness”.
Dylan said: “While conducting a SWF boat survey, we observed intense splashing and dolphin activity.
“At first, we saw something flung into the air and suspected a porpoise, but to our disbelief, it was a common dolphin calf, making this encounter an interspecific infanticide.
“I was filming for a personal documentary at the time and couldn’t believe I had captured such a rare behaviour between different dolphin species.”
A guide for Dolphin Spotting Boat Trips, who hosted the trip, Sarah Michelle Wyer, said: “It was an incredibly rare encounter... I've never seen that behaviour before.
“It's very common for bottlenose dolphins to attack porpoises, but not a common dolphin calf.”
Sea Watch Foundation has monitored the dolphin population off Cardigan Bay for over 20 years.
A charity spokesperson said that male dolphins are known to kill bottlenose dolphin calves and porpoises as well as “show aggression to other cetacean species”, but that SWF had never witnessed this aggression towards common dolphins before.
The Foundation states that, though it is difficult to pinpoint the cause for the behaviour, possible competition for resources such as food may play a role.
A post-mortem of the calf may provide further insight into the event.