At two different universities, the University of York and the University of St. Andrews, the psychology department has observed, over an eight month period, tool use from 10 captive greater vasa parrots (Coracopsis vasa). The parrots were seen using small pebbles or date pits to grind down seashells or to break apart the shells into smaller consumable sizes. This grinding, believed to be used to get calcium in their diets, is the first time grinding has been seen in non-humans. 5 out of the 10 birds were observed using this technique, with an increase of grinding occurring from March to April, coinciding with this species' breeding season.
Parrots are not the only species known to use tools, as another species known to use tools is the Egyptian vulture (Neophron percno pterus). A species of raptor, these birds are generally detritivores, but are also known to eat eggs. In order to do this, Egyptian vultures will search within 50 yards for a rock, which the bird will then use to smash open the eggs, with an average accuracy of 40-60 percent. The motion used to throw rocks is also the usual pecking motion of these vultures, so it is believed that this learned trait developed when Egyptian vultures started using eggs as a food source.
Another bird species known to use tools is the woodpecker finch (Camarhynchus pallidus). Lacking the long barbed tongue of its namesake woodpecker, this species of finch compensates by using a small twig or cactus needle to pry out grubs from wood. The woodpecker finch has also been observed to keep the tool it used for multiple uses.The finches generally try to acquire the grubs by using their long and pointed beaks to dig into the wood without the use of tools, however, as it is a long process.
The most famous reports of birds using tools is crows who drop down seeds onto the road, where they will be run over by cars so the crow can eat the nut insides. This is not the only tool crows can use. Take this species: the new Caledonian crow (Corvus moneduloides). These crows are known to use twigs for purposes that are meant for more than just eating. Like the woodpecker finch, twigs are sometimes used in order to acquire food, and the new Caledonian crows also use those twigs to poke at foreign and random objects, with a different attitude towards them than when they are searching for food. It is believed that this might be a way to help these birds understand whether things are inanimate or not, or to help them understand if an object is a threat.
