Kiwi researchers have used drones to capture stunning footage of Bryde's whales foraging off Auckland's coast.
Auckland University of Technology post-graduate students Ticiana Fetterman and Lorenzo Fiori were out on the water when they were able to use an unmanned aerial vehicle (UAV) to film a whale feeding, briefly joined by a young calf.
The pair were stunned to glimpse the whales, and to share the rarely seen moment with their research supervisor Dr Barbara Bollard Breen.
"Bryde's whales are critically threatened in New Zealand, so it's thrilling to see them in the wild and to be able to record them feeding from above is very special," said Dr Bollard Breen, a senior lecturer in geospatial science.
"Using a UAV allowed Ticiana and Lorenzo to film without disturbing the surrounding wildlife -- revealing footage of the whales feeding that we wouldn't have been able to see from a boat-based survey."
The team was using a custom-built multi-rotor UAV, one of a number of drones used by AUT's Institute for Applied Ecology in their conservation and ecology research.
It flew at a distance of at least 40 metres from the whales, while recording clear, detailed footage.
The adult whale was estimated to be around 12 metres long, 12 tonnes in weight and 10 years old.
Around 50 Bryde's whales are estimated to live year-round within the Hauraki Gulf, mixing with another 150 seasonal visitors; one of the few resident populations of this species in the world.
Dr Rochelle Constantine, a senior lecturer at the University of Auckland's School of Biological Sciences, said long-term research projects had been tracking the species around the gulf since the mid-1990s.
"What we know now is they use different foraging strategies when they are feeding on different prey items, and this is unusual for baleen whales," she said.
"So there is a study going on looking at the energetics and mechanics of that, and the advent of drones has been a really useful addition for scientists throughout the world studying their foraging behaviour.
"AUT using drones to capture this footage of Bryde's whales in the Hauraki Gulf adds to our knowledge of the species throughout the world."