Abstract/Summary

Earth is experiencing an anthropogenic biodiversity crisis driven by habitat loss, climate change, invasive predators, and over-exploitation. Islands have high levels of unique biodiversity but are simultaneously more susceptible to these threats, and consequently species declines and extinctions are more common on islands. Practical conservation interventions are therefore vital, but fully assessing their outcomes requires detailed datasets which can only be created by long-term monitoring, and which remain rare for tropical species of conservation concern. This thesis uses one such dataset to explore impacts of conservation management on demography of the endangered island endemic Mauritius fody Foudia rubra. Results demonstrate that individual productivity is primarily driven by breeding phenology, as birds who initiate breeding early have higher nest productivity and higher re-nesting rates; these components of fitness contribute to higher seasonal reproductive success. Within this population, birds on territories nearer to feeding stations initiate breeding earlier than their peers further away, and this demonstrates that management has a positive but indirect impact, mediated by the influence of territory quality on breeding phenology. Various stochastic and climatic processes influence productivity both negatively and positively, and there is an interesting interaction between pre-seasonal rainfall and the within-season relative start of breeding. Finally, demographic modelling determines that access to supplemental feeding improves population growth and persistence, and reduces risk, across a range of potential management scenarios, demonstrating that management can reconcile the dual roles of this population as both a refuge and as a source for new populations. These results allow management recommendations to be made for this species to improve efficiency; and a greater understanding of the scale of and mechanism by which supplemental feeding can improve outcomes will be relevant to other species facing similar threats. As such, this study can answer calls within conservation for a greater emphasis on fully evaluated practical interventions in addition to conservation science limited to assessment of threats.