A drone offered thousands of compelling aerial images of endangered killer whales — including seemingly pregnant ones — to federal biologists this week.

The drone flown near San Juan Islands in Washington captured photos of the the 81-member orca population spending some time in Canadian waters. The photos are used by National Oceanic and Atmospheric Administration (NOAA) researchers, as well as those with the Vancouver Aquarium in British Columbia, for measuring and monitoring the whales’ growth and wellness.

According to Southwest Fisheries Science Center's marine mammal biologist John Durban, they were simply looking at whether the killer whales were getting enough to eat.

He said feeding appeared to be good, partly due to the five new calves born and welcomed in the population in the past year or so, and that several animals appeared to be on the way.

The researchers also sought details on the size and length of the whales from one year to another, their reproduction rate, any changes in body conditions, and how such factors connect with the number of salmon they need to consume.

Wildlife is now being tracked using drones, such as in the case of seals and penguins in Antarctica and humpback whales situated off New England. The technology, also known as a hexacopter, is targeted to reach whales, birds, and wildlife in areas that are difficult to reach and where small devices can create minimal disturbance.

Helicopters previously used on such expeditions, for example, were expensive and flew at much higher altitude, unlike the drone hovering around 100 feet over the whales and offering sharper images without destroying peace.

The rich images including that of mother orca nursing its baby and a whale with a newborn orca all offer a look at the marine creatures’ social bonding.

"You see that they’re spending most of their time swimming so close together they can touch,” observed Lance Barrett-Lennard, Vancouver Aquarium's cetacean research program head, adding that although the whales are capable of long-distance communication, “[t]his is something they want to do. It's part of how they maintain social bonds.”

Killer whales, which mostly consume Chinook salmon, have seen a decline in numbers due to decreasing food, marine contaminants, and vessel traffic disturbance.

The mix of El Nino this winter and warming ocean temperatures is expected to lead to poor returns for prospective Chinook salmon runs and adverse effects on the species' food supply.

Photo: Rennett Stowe | Flickr

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