A drone has managed to capture rare footage of two Bryde's whales feeding. The video shows an adult whale joined later by a calf breaking through the water's surface before diving down again in search of food.

The custom-made drone belonging to Auckland's University of Technology captured what they believe might be the "world-first footage" of the two whales off the city's coast. The water-proof instrument was procured by the university in order to monitor species conservation and map New Zealand's environment.

Senior geospatial science lecturer Dr Barbara Bollard-Breen said the find was "completely unexpected".

"I was in awe of these creatures. Never before have I seen anything like this. There is no way we would see so much detail from a boat-based survey," she said.

The video shows the adult 12-tonne, 12m whale opening its mouth to feed on plankton and later being joined by the calf who continues to swim with it for a while.

"It was pure excitement when I was filming, and it's simply a joy to see every time I watch it," PhD candidate Lorenzo Fiori said.

Bryde's whales are considered critically threatened, with less than 200 recorded in New Zealand waters, the university said. Using the drone enabled the research team to record this normally unseen event without disturbing the whales.

Bryde's Whale
Bryde's whale off the coast of AucklandAuckland University of Technology