The role of trust in public attitudes toward invasive species management on Guam: A case study.

Public attitudes toward invasive alien species management and trust in managers' ability to effectively manage non-native species can determine public support for conservation action. The island of Guam has experienced widespread species loss and ecosystem transformation due to invasive species, most notably, the brown treesnake (Boiga irregularis). Despite Guam's long history with invasives and extensive efforts to eradicate them, we know little about the sociological context of invasive species and drivers of public support or opposition on the island. Using focused group discussions, we explore public attitudes toward invasive species management measures. Respondents were familiar with the common invasive species on Guam and recognized that they were not native. They expressed support for management activities, interest in more effective and frequent management initiatives, and desire to participate directly in conservation actions. Participants also expressed frustration with government institutions and lack of confidence in managers' ability to control invasive species. Perceptions of managers' trustworthiness, communication with managers, and positive personal experiences with managers were related to positive attitudes about management and support for existing initiatives, indicating the important role of trust and engagement for invasive species management.

Contrasting ecological roles of non-native ungulates in a novel ecosystem.

Conservation has long focused on preserving or restoring pristine ecosystems. However, understanding and managing novel ecosystems has grown in importance as they outnumber pristine ecosystems worldwide. While non-native species may be neutral or detrimental in pristine ecosystems, it is possible that even notorious invaders could play beneficial or mixed roles in novel ecosystems. We examined the effects of two long-established non-native species-Philippine deer (Rusa marianna) and feral pigs (Sus scrofa)-in Guam, Micronesia, where native vertebrate frugivores are functionally absent leaving forests devoid of seed dispersers. We compared the roles of deer and pigs on seedling survival, seed dispersal and plant community structure in limestone karst forests. Deer, even at low abundances, had pronounced negative impacts on forest communities by decreasing seedling and vine abundance. By contrast, pigs showed no such relationship. Also, many viable seeds were found in pig scats, whereas few were found in deer scats, suggesting that pigs, but not deer, provide an ecosystem function-seed dispersal-that has been lost from Guam. Our study presents a discrepancy between the roles of two non-native species that are traditionally managed as a single entity, suggesting that ecological function, rather than identity as a non-native, may be more important to consider in managing novel systems.