Stranger danger: acoustic response of the Veery (Catharus fuscescens) via heterospecific eavesdropping on the Tufted Titmouse (Baeolophus bicolor)

Abstract

ABSTRACT In this study I examined heterospecific eavesdropping in passerines by investigating how information broadcast by the Tufted Titmouse (Baeolophus bicolor) at dusk modifies singing and calling vocalizations of a common avian dusk chorus species, the Veery (Catharus fuscescens). The Veery nests on or near the ground and is a highly vocal participant of the avian dusk chorus, which also renders it vulnerable to a wide array of diurnal and crepuscular predators. Thus, the Veery is expected to be sensitive to signals of predation risk. Here, I report findings of simulated exposure to indirect predation risk (recorded playbacks of Tufted Titmouse alarm calls) that alter acoustic output by the Veery. From 19 May to 6 July 2013, 14 plots in Veery territories were selected and exposed to playback calls of the gray tree frog (Hyla versicolor; control treatment) and playbacks of the Tufted Titmouse high seet call (experimental treatment). Each plot was subjected to two 65 min playback-recording trials (one ...