Marine scientists tagging pygmy blue whales off the Ningaloo coast in Western Australia (WA) have spotted a tiny calf, thought to be the smallest of the species ever sighted in Australian waters.
The little calf photographed swimming alongside its feeding mother off the coast of WA was captured by spotter pilot Tiffany Klein from Ningaloo Aviation during a research project to satellite tag pygmy blue whales undertaken by the Australian Institute of Marine Science (AIMS) and the Centre for Whale Research (CWR).
Photographs and video footage of pygmy blue whales are helping scientists draw back the veil on the mysterious reproductive lives of these endangered animals.
The Ningaloo calf was about a third of the size of its mother – approximately 6-7m – and the researchers think the calf is just weeks old.
“Looking at the size of the calf compared to its mother, it’s possible it may have been born in waters near key feeding grounds in the Perth canyon further south,” says AIMS lead research scientist on the project, Michele Thums.
“Some experts think they may give birth, or calve, soon after leaving their foraging grounds, which for this population is the Perth canyon.
“No one really knows where pygmy blue whales calve, but here in the Indian Ocean, they are thought to breed and calve at the end of their northward migration off WA’s coast and in Indonesian waters.
“Having consulted with other experts in that region, a calf of this size is not something that’s been observed before by any of them.”
Meantime to the north west of Australia at the whale nursery near Timor-Leste a decade-long citizen science program has captured also some of the first-ever recorded evidence of reproduction in pygmy blue whales, including underwater footage of a mother nursing its calf.
Underwater video footage of a pygmy blue whale mother and nursing calf, captured for the first time. Credit: Angel Lai / ‘Insider Divers’ 2022 Expedition
Leader of the citizen science program, marine ecologist Karen Edyvane of Charles Darwin University, says the blue whale’s reproductive and calving behaviour has remained largely unknown in the scientific community.
“Our program has documented some of the lesser-known, intimate reproductive behaviours of blue whales, some for the very first time. It’s very, very exciting,” she says.
“From newborn calves and nursing mothers to amorous adults in courtship, the waters of Timor-Leste really are providing blue whale scientists with some of our first glimpses into the private lives of one of the world’s largest but most elusive animals.”
Dr Capri Jolliffe of Curtin University says the long-term monitoring in Timor Leste is providing critical insights into the ecology of the Austral-Indonesian population of pygmy blue whales.
“This research clearly highlights that the life history characteristics and patterns of habitat use of pygmy blue whales differ significantly from their Antarctic blue whale counterparts. They really are tropical animals,” says Jolliffe.
Pygmy blue whales (Balaenoptera musculus brevicauda) are a smaller subspecies of blue whale, growing to lengths of about 24 meters compared to the larger 30m.
AIMS and CWR scientists use satellite tags and dive loggers to better understand their migratory routes and key feeding areas in Australia.
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