dataset-Host provisioning behaviour favours mimetic begging calls in a brood parasitic cowbird

Playback experiment to assess the effectiveness of the nestling call structures of two brood parasites, the specialist screaming cowbird (Molothrus rufoaxillaris) and the generalist shiny cowbird (M. bonariensis), in stimulating parental provisioning in 25 nests of a shared host, the baywing (Agelaioides badius). The effect of playback treatments on the number of feeding visits by baywing adults was analysed using generalised linear mixed models (GLMM) with log link function and Poisson error structure. Models were fitted using the glmer function included in lme4 package in R 3.1.2 (R Core Team 2014; Bates et al. 2015). Explanatory variables were playback treatment, treatment order and clutch composition (presence/absence of parasites), with nest identity included as a random effect.