The Ability of Parrots to Navigate Thin Branches Using Their Beaks

Parrots use their beaks for more than just eating or vocalizing.

In order to navigate thin branches, they can hang from them using their beak, swing their bodies sideways, and then grab onto a further point on the branch with their feet. This newly identified method of movement, named beakiation, demonstrates the multi-purpose nature of a parrot's beak and enhances our understanding of avian mobility, as published in the January 31 issue of Royal Society Open Science.

Parrots are naturally adept at climbing and traversing trees, highlights Michael Granatosky, a biomechanist at the New York Institute of Technology in Old Westbury. He initiated a study to see how these birds would adapt when presented with unique movement challenges.

Granatosky and his team conducted a test on four rosy-faced lovebirds (Agapornis roseicollis). The birds were placed on a suspended bar with a diameter of just 2.5 millimeters. The most effective way for the birds to traverse the bar was by employing a cyclical side-swinging technique using their beaks and feet. Their average travel rate was 10 centimeters per second for each stride, measured from beak landing to the next beak landing.

Edwin Dickinson, another biomechanist at NYIT, emphasized that the parrots were not trained for this activity. Instead, they innovatively solved a new challenge, proving their intelligence.

An instrument measuring force was used to hang the central section of the three-part bar where the birds stood. Through this and several other measurements from 129 strides, the researchers could judge the energy efficiency of beakiation. The birds were found to lose most of the energy they exerted with each swing, only recovering about 24 percent of the energy through the slow, pendulum-like movement.

This was contrasted with gibbons (Hylobatidae), who recover nearly 80 percent of their energy during a stride when swinging between branches using their arms, in a smooth and quick motion known as brachiation. Conversely, beakiation comprises cautious movements punctuated with starts and stops.

David Lee, a biomechanist from the University of Nevada in Las Vegas, who was not involved in the research, sees beakiation as just one of many beak-aided movements parrots employ. He notes that parrots typically inhabit dense forests where flight can be challenging; oftentimes, their only available paths are vines and delicate branches. He said, “They’re navigating complex 3-D environments all the time.”