Analyzing the effects of urbanization on the instance of mimicry in gray catbird (Dumetella carolinensis) song

Christopher Will

Abstract

Increased urbanization is having a negative impact on species that communicate vocally, one largely impacted group being different species of songbirds. Habitat modification causes a loss of species richness along an urban gradient. The lower the species richness, the less species of songbirds there are in the habitat. The gray catbird, Dumetella carolinensis, is a vocal mimic belonging to the Mimidae family. This species derives aspects of their song by mimicking sounds from their environment. I sampled recordings of gray catbird song and identified instances of mimicry from a subset of 12 indicator species representing an urban gradient. Results show that males belonging to habitats in urban and suburban levels of urbanization significantly mimic more urban indicator species. Results also showed trends that support the intermediate urbanization hypothesis for suburban males. By providing one of the first studies to my knowledge that has connected species imitated by a vocal mimic to the species present along an urban gradient, I provide a context for future studies on avian vocal mimicry.