Eradication of invasive common mynas Acridotheres tristis from North Island, Seychelles, with recommendations for planning eradication attempts elsewhere

Introduced common mynas (Acridotheres tristis) can negatively impact native wildlife throughout the mynas’ non-indigenous range, and in Seychelles myna eradications have been attempted on some smaller islands to protect endemic and indigenous fauna. Initial attempts, relying on a quick knock-down of the population using toxicants, failed. Here we describe an eradication on North Island, Seychelles, that was accomplished by trapping, supported by shooting in the final stages. This eradication attempt was ultimately successful but took place in two stages spanning seven years and involved removing 1641 birds. During the second, successful, stage, morphometric data collected from caught mynas provided pointers to optimum times during the mynas’ annual cycle to target control activities. During both stages the trapping of non-target species interfered with the capture of mynas. The six main conclusions from this eradication are (i) eradication of mynas from small islands is feasible and achievable by trapping and shooting, without recourse to the use of toxicants; (ii) provision of adequate resources for the life of an eradication attempt, especially ensuring continuity of funding and staffing, is essential for the efficient removal of the whole population; (iii) knowledge of myna phenology can be used to target the optimal timing of an eradication attempt, (iv) post eradication, vigilance and capacity for immediate action must be maintained to remove any immigrant mynas, (v) further research on trap design is needed to minimise the capture of non-target species, and (vi) introduced endemic bird populations should be monitored to assess their responses to myna removal.