Population suppression of urban common mynas (Acridotheres tristis) by citizens: short-term effects on local avifauna and succession among the despots

Context Calls for expanding community-driven efforts to reduce introduced populations of common mynas (Acridotheres tristis) continue. Although the detrimental effects of common mynas on avian community composition and richness are well established, eradication has proven possible for island populations, and information on the efficacy of population suppression efforts of mainland urban populations is sparse. Aims We assess changes in avifauna associated with community-based control of urban common mynas. Methods We conducted replicate transect counts of birds in Melbourne, Australia, within an area where common mynas were suppressed and an adjacent area where no suppression occurred, before and during the suppression. Key results Population suppression reduced relative abundance of common mynas but did not alter overall species richness or diversity, including native and introduced taxa. However, on a species-specific level, suppression was associated with both increases and declines in large and small species, whether native or non-native. The largest positive response coincident with common myna suppression was an increase in the aggressive noisy miner (Manorina melanocephala) which, like common myna, detrimentally affects other native birds. Conclusions Community-based trapping reduced common myna relative abundance, but did not increase overall terrestrial bird richness or diversity; instead, responses were species-specific, including an increase in the native and aggressive noisy miner. Implications Complex interaction webs likely occur in urban birds, and possible functional redundancy of common mynas may influence outcomes of suppression, creating a new set of “winners” and “losers”.