Universal Approbation

14 populations of humpback whales: 9 (blue) not at risk
4 (pink) endangered, 1 (yellow) threatened. (NOAA)

The worldwide humpback whale population has recovered almost completely. However, four of the fourteen populations are still classified as "endangered."

Meanwhile, scientists at the Hawaiian Islands Humpback Whale National Marine Sanctuary continue to perform basic research into the species.

Among their findings: [bold added]

Humpback whales, the winter stars of Hawaii’s marine environment, have been arriving and leaving island waters earlier than normal in recent years, according to a trend documented by scientists.

Other recent research suggests there actually may be two subpopulations of humpbacks coming to the island chain, and it appears that the marine mammals take what some might described as an afternoon siesta each day.

Mother and calf at the sanctuary.

Drone and acoustic devices have tracked the whales' movements:

Surprising was strong chorusing in the northern part of the chain, with a region of relatively little whale sound wedged between the area of strong chorusing in the southern part of the chain, including the main islands.

“The structure of the whale population is more complex than previously thought,” Lammers said, adding that it might point to two subpopulations, one tied to the southeastern part of the archipelago and main Hawaiian Islands and one clustering toward the northwestern end.

But to really confirm that, he said, scientists will have to go up there and investigate.

“These data are certainly interesting and motivating us to go out and try to get more data from that area,” he said.

In another area of research, scientists have been studying behavior using suction cup tag monitors that they attach to individual whales. The tags record sound, video, depth levels and movements.

A recent study examined 86 hours of video from 25 different tagged whales and scored activity levels during different times of the day. A distinctive pattern emerged in the afternoon: decreases in activity and surfacing, and more resting.

“It looks like whales have a real tendency to rest between 1 and 4 p.m. This is something that anecdotally people have noticed, but there’s never been any quantitative evidence,” Lammers said.

“This is really new and exciting stuff for us — that we’re able to show these pretty clear patterns of resting behavior in the afternoon hours,” he said. “It’s kind of reminiscent of another species that we have here, the spinner dolphin, which is very active during nighttime hours but then spends its daytime hours more in a resting state.”

Surveillance technologies are controversial when applied to humans, but in animal studies, especially with species that are endangered, they are regarded with universal approbation.