Hawaiian Islands Humpback Whale National Marine Sanctuary just released video footage captured a month ago of an unusual behavior among humpback whales. The whale, a female with her calf, does a headstand with her tail out of the water, catching the wind sort of like a sail.

According to NOAA, "tail-sailing is fairly common among southern right whales but has rarely been observed or documented among humpbacks."

"We're not entirely sure why the whales do this," said Ed Lyman, resource protection specialist for 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 video footage was captured as whale researchers and managers were testing how small unmanned aircrafts could be used for whale research. (They managed to capture this unusual behavior on camera during testing, so we suspect the answer is yes.) The unmanned crafts may also prove to be useful for disentanglement efforts within the marine sanctuary. NOAA explains in more detail:

Equipped with tiny but powerful cameras, small, quiet, electric quadcopters can provide a safe, cost-effective, low-impact way to assess, document, and even collect biological samples such as whale blow.

During the two-week study, the research team observed more than 15 humpback whales, including mothers and calves and competitive groups of males chasing after individual females ...

Lyman said the use of small UAS [Unmanned Aircraft System] platforms likely provide a safe and productive means to obtain general health and risk assessment on the animals without a human physically approaching the animal.

Jaymi Heimbuch ( @jaymiheimbuch ) focuses on wildlife conservation and animal news from her home base in San Francisco.

Rare whale behavior called tail sailing caught on video
This behavior has been seen in Southern right whales, but is rarely witnessed among humpback whales.