Why was a humpback whale caught in a headstand?

A recently released video taken by a scientific research drone off the coast of Maui, Hawaii caught a humpback whale in an unusual position: swimming vertically with its tail above the water.

The whale “headstand” was captured in February by an unmanned aircraft system (UAS), or drone, operated by researchers with the National Oceanic and Atmospheric Administration (NOAA) Collaborative Center for Unmanned Technologies. The video was released by the Hawaiian Islands Humpback Whale National Marine Sanctuary in Maui on Wednesday.

The short clip shows the NOAA UAS approaching a female humpback whale swimming with her calf. As the young mammal darts around its mother, the older whale remains situated with her body facing downward in the water with her tail floating above the ocean's surface.

A sanctuary release regarding the video explained that while right whales are known to tail-sail, the practice has “rarely been observed or documented” in humpback whale populations.

“We're not entirely sure why the whales do this,” said Ed Lyman, a whale specialist with the sanctuary. “But we think this could be another way for them to rest, nurse, or just try to stay cool. More observations will be needed to confirm this theory.”

The tail-sail caught by NOAA appears to be relatively uncommon, but the practice may be related to humpback whales’ tendency to breach. Breaching, or cresting, involves the mammals propelling themselves out of the water and is most commonly seen from humpback, right, and sperm whales. The reasoning behind breaching is also not confirmed. It has been suggested that the whales may be attempting to scratch an itch, communicating with each other, or simply having fun.

The humpback headstand video was captured during testing for the NOAA unmanned technology center’s potential future UAS programs. The center’s scientists were working to see if drones such as the quadcopter used to film the whales could be effective in studying whales at the important Hawaiian sanctuary. The unique habitat, which was established by Congress in 1992, is the only National Marine Sanctuary to focus on a single species – humpback whales.

According to the sanctuary, each February sees around half of all North Pacific humpbacks arrive at the Valley Isle’s coastal refuge, where they breed, give birth, and nurse calves.

NOAA and Sanctuary scientists hope that in addition to whale research, using UASs around the humpback preserve could aid them with disentanglement efforts by allowing them to find whales in distress. Boating around the animals could cause further anxiety during an already upsetting experience for the creatures, while the small and quiet drones may prove less disruptive.

“The typical boat-based close approaches needed to assess an entangled whale can be very challenging and dangerous,” Mr. Lyman said “Animals may become more evasive or aggressive.”

Although the two-week long NOAA UAS testing was declared a success, there are still regulatory and safety considerations to address before drone use to study the whales could be standardized, including a firm evaluation of the potential for “incidental harassment” of the animals, according to a NOAA entanglement response coordinator.

“Everyone from state and federal managers and regulators to the end users will need to continue working together to evaluate the efficacy and pursue the appropriate use of UAS platforms as extremely valuable tools,” UAS advocate and Woods Hole Oceanographic Institution senior biology researcher Michael Moore said.