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 after giving birth to a presumed deceased calf. She remained with it for several hours and possibly even days.

Dr. Olaf Meynecke, from Griffith University's Whales and Climate Research Program, said postmortem attentive behavior in cetaceans had been documented predominantly among toothed whales and delphinids (known as odontocetes), but remained largely absent from research published on baleen whales, like 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 postmortem behavior and attention toward her deceased calf under the surface," Meynecke said.

A rare view beneath the surface

"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 behaviors were consistent with caregiving or nurturing actions and postmortem attentive responses documented in socially complex mammals, and indicated an inherent, strong maternal attachment to the calf."

Cetaceans are among the most charismatic marine species receiving widespread public attention.

Rescue boat Capt. 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 behavior was unusual.

"It was definitely not what I was expecting to see out at sea that day."

A case that expands the record

Meynecke said this observation in 2025 and others involving deceased calves were incredibly sad, 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 postmortem behavior in large whales," he said.

"Understanding how nonhuman animals responded to death provides insight into their emotional lives, social bonds and cognitive capacities."

The study "First documentation of humpback whale (Megaptera novaeangliae) postmortem attendance of a stillborn" has been published in Discover Animals.