Humpback whale mothers may experience grief when their calves die, a rare research observation led by Griffith University and Sea World Foundation has found.
In 2025, a female humpback whale - along with an escort whale - was observed off the southern Gold Coast who had given birth to a presumed deceased calf and remained with it for several hours and possibly even days.
Dr Olaf Meynecke, from Griffith University's Whales and Climate Research Program, said post-mortem attentive behaviour in cetaceans had been documented predominantly amongst toothed whales and delphinids (known as odontocetes), but remained largely absent from research published on baleen whales, such as humpback whales.
"Unlike reports of toothed whales where mothers have been observed lifting their dead calves to the surface, this humpback whale mother showed prolonged post-mortem behaviour and attention towards her deceased calf under the surface," Dr Meynecke said.
"She remained close to the calf, maintaining eye contact and positioning herself next to her calf over several hours and maybe even days.
"These observed behaviours were consistent with care-giving or nurturing actions and post-mortem attentive responses documented in socially complex mammals, and indicated an inherent, strong maternal attachment to the calf."
Cetaceans were some of the most charismatic marine species receiving regular widespread public attention.
Rescue Boat Captain Andrew Mulville from Sea World Foundation, who witnessed the event, said: "When I actually worked out what was happening, I was totally surprised."
"At first sight, I thought it was just two whales resting on the surface, but their behaviour was unusual.
"It was definitely not what I was expecting to see out at sea that day."
Dr Meynecke said while this observation in 2025 and others with deceased calves were incredibly sad, they were rare and added to the limited current understanding of the cognitive and emotional dimensions of death-related responses in baleen (filter-feeding) cetaceans.
"This case study highlights the need for continued systematic documentation of rare neonatal mortality events to better understand the cognitive, emotional, and evolutionary significance of post-mortem behaviour in large whales," he said.
"Understanding how non-human animals responded to death provides insight into their emotional lives, social bonds, and cognitive capacities."
The study 'First documentation of humpback whale (Megaptera novaeangliae) post-mortem attendance of a still born' has been published in Discover Animals.
