Research has shown that a number of animals, including birds, are capable of using tools in specific contexts. Until recently, only three species of parrots (out of 400) were known to be tool users. A new study by UK researchers, however, has shown that a fourth species of parrot can use tools. Moreover, the ground-breaking new research has not only confirmed that parrots use tools, but also demonstrated that greater vasa parrots are the only other known animal (besides humans) to use grinding tools.
The new study on tool use among parrots was published on December 16th in the academic journal Biology Letters.
Research proves greater vasa parrots use tools
A team of animal psychologists at the University of York and University of St Andrews in the UK offer convincing proof of tool use by greater vasa parrots (Coracopsis vasa). In a study involving ten captive parrots, the researchers observed the birds using a novel tool-using technique to produce digestible calcium from seashells as well as sharing tools among themselves.
The team saw the birds using small pebbles or date pits to grind or break off small pieces of shell to ingest. This behavior has never been seen in this species, and is the first time a nonhuman has been observed using tools for grinding. The new study is also one of only a very few reports of nonhuman animals directly sharing tools.
The UK researchers observed and filmed the parrots over eight months to document their various interactions with the cockle shells on the floor of their aviary. Of note, sea shells are a well known source of calcium for birds.
In the recent study, five out of ten birds were filmed using tools, putting pebbles or date pits inside of cockle (mussel) shells to grind against the shell, or in some cases using the pebble to chip away at the seashell to break off pieces.
The researchers highlight that interest in the shells among the parrots was greatest from March to mid-April, a few weeks before the breeding season, so it is possible the behavior is related to calcium supplementation for egg-laying. That’s why the team was quite surprised to find that it was the males who showed the greatest interest in shells.
Further observation of the parrots’ breeding behavior, however, demonstrated that males often fed females regurgitated food before copulating, thus likely passing on the egg-laying benefits of the calcium.
Statement from lead author of parrot study
Megan Lambert, a doctoral student in York’s Department of Psychology and lead author of the study proving parrots use tools, commented: “The use of tools by nonhuman animals remains an exceedingly rare phenomenon. These observations provide new insights into the tool-using capabilities of parrots and give rise to further questions as to why this species uses tools. Tool use could reflect an innate predisposition in the parrots, or it could be the result of individual trial and error learning or some form of social learning. Whether these birds also use tools in the wild remains to be explored, but ultimately these observations highlight the greater vasa parrot as a species of interest for further studies of physical cognition.”