It was clear to the researchers that these tools seemed precious to the birds.
"In one scene," said Troscianko, "a crow drops its tool, and then recovers it from the ground shortly afterwards, suggesting they value their tools and don't simply discard them after a single use."
10 Surprising Facts About Animal Intelligence
The crows (Corvus moneduloides) observed in the study live in the South Pacific, on the island of New Caledonia, and it's thought that corvids such as these may even rival primates in the area of brain power.
They've honed the art of using their bills to whiddle twigs and even leaves into hooked bug-grabbers. One crow seen on the recordings only needed one minute to create its tool, before using it to probe leaves on the ground and tree hollows in search of bugs.
Vultures And Other Animals With Iron Stomachs: Photos
The team found the birds appreciated efficiency in their labors and had a disdain for carelessness.
"Crows really hate losing their tools, and will use all sorts of tricks to keep them safe," said Rutz. "We even observed them storing tools temporarily in tree holes, the same way a human would put a treasured pen into a pen holder."
The birds are highly attuned to disturbances in their midst, and their tropical habitat can also be a hindrance to anyone wishing to get a close look at how they earn their living. But the cameras the team employed afforded just such looks.
"By documenting their fascinating behavior with this new camera technology," said Troscianko, "we obtained valuable insights into the importance of tools in their daily search for food."