A crow in a Yokohama park adjusts the water fountain faucet for drinking and bathing. (Video footage provided by Hiroyoshi Higuchi)

Stone the crows! There's a bird of that species that is so observant it has learned how to activate a water fountain faucet to quench its thirst or take a shower.

Hiroyoshi Higuchi, professor emeritus of ornithology at the University of Tokyo, reported his findings in the academic journal British Birds issued on March 1.

"Crows living in urban areas carefully observe the actions of humans, which raises the prospect that they do so to utilize tools created by humans for their own purposes in the future," Higuchi said.

Having heard reports about crows drinking from taps after activating the faucet, Higuchi started observing the birds at a water fountain in Gumyoji Park in Yokohama's Minami Ward.

During his visits between March and April 2018, Higuchi watched a dozen or so crows that frequented the park. One, however, stood out: a female carrion crow that had taught itself to use the water fountain.

Higuchi observed that particular crow for a total of 79 hours and found it drank from the fountain 21 times and even took a shower on four occasions.

When the crow wanted a drink, it pecked at the faucet with its beak so that water emerged from the tap at a height of a few centimeters, making it easier to drink.

However, when the bird felt the need for a shower, it clamped down on the faucet with its beak to turn it. That led water to shoot up as high as 50 to 80 centimeters.

The crow was not sufficiently dextrous to return the faucet to a closed position. Human visitors to the park closed the faucet when they noticed water spouting out of the fountain.

The male companion of the carrion crow as well as other crows at the park never touched the faucet.

Higuchi kept visiting the park, but after a while this particular bird stopped showing up.

There have been other sightings of clever crows taking their cue from humans.

Crows in Miyagi and Akita prefectures have been spotted placing walnuts on public roads so that passing cars cracked the hard shells.

But Higuchi said it was much rarer to come across crows that had learned to operate tools created purely for the use of humans.