It's seeming like there are plenty of tool-using animals.
Russell Balda has documented an apparent case of weapon use by not just one, but two species of birds -- a Steller’s jay and an American crow. [...]
So Balda, on an April morning three years ago, is in his office outside which is a meter-square feeding platform. A crow is on the platform eating sunflower seeds. Two jays—maybe a pair; it’s hard to tell with jays—land in a nearby mountain mahogany bush. The jays seem annoyed by the crow’s presence. One flies to the platform and scolds the larger bird, which fails to react. The jay feints toward the crow with its bill; the crow feints back. The jay flies up to the roof of the building, then divebombs the crow. The crow keeps eating. End of Round One.
Then the jay does something remarkable. It goes back to the mountain mahogany and breaks off a twig from a dead branch. Holding the twig in its beak, pointed end forward, it returns to the feeding platform and lunges at the crow. It’s a near miss. The crow lunges in its turn, startling the jay, which flies up and drops the twig onto the platform.
And the crow picks it up, again pointed end forward, and thrusts it at the jay. Whereupon the jay on the platform and its partner in the bush both fly off, pursued by the twig-carrying crow.
Previously: This bird-brain is pretty smart.