Two unusual black wolves that are believed to be siblings, were caught on camera crossing a stream in a forest in Poland, according to a conservation organization.

The rare sighting, which was captured on video last year, has prompted the SAVE Wildlife Conservation Fund Poland to retrieve scat droppings in the forest that the wolves were observed in, so scientists can learn more about the genetics of the black wolves.

The Associated Press reported that the video camera was set up by Joanna Toczydlowska, a project coordinator with the wildlife organization, to study beavers.

But she was surprised when she reviewed the recorded footage and saw wolves instead. She decided to leave the camera in place to learn more about the rare animals.

One of the black wolves was spotted with a gray wolf. (SAVE Wildlife Conservation Fund Poland via AP)

Toczydlowska said the two black wolves were likely siblings and about a year old, which she hypothesized on the basis that wolves travel in families and the two were about 66 pounds. She also said at least one of the black wolves spotted was a male.

Wolves were nearly extinct in Poland by the 1950s, though the population has rebounded in recent years, particularly in the central part of the country.

Toczydlowska and her colleagues help educate the public on how to safely live in areas inhabited by packs of wolves.

“For people, it’s a new phenomenon,” Roman Gula, head of the organization’s wolf monitoring project, told the AP. “Education is one of our major, major goals.”

The Associated Press contributed to this report.