An analysis of a bird species' unique rasps shows how sound fluctuations in birds' songs might reveal details about birds' body sizes.
The white-tipped plantcutter is a reddish, small bird, that emits a distinct hoarse groaning sound. It is not a vocal learner, meaning it has little motor control over the sounds it makes. Instead, the bird relies mostly on biomechanics to sing its rasp. Now, researchers studying the biomechanics of the white-tipped plantcutter's rasp have determined how to gauge the bird's size through its vocalizations. Uribarri et al. analyzed recorded bird songs and employed computational models to assess song segments. They found a relationship between the frequency of resonating sounds from birds' oro-esophageal cavities and birds' sizes. The scientists also checked the correlation between song and size by testing museum specimens. The results suggest that the biomechanics of bird sounds could potentially be used to predict bird size.
Unusual avian vocal mechanism facilitates encoding of body size
Gonzalo Uribarri, María José Rodríguez-Cajarville, Pablo Luis Tubaro, Franz Goller, and Gabriel B. Mindlin