Controlling invasive species presents a public‐good dilemma. Although environmental, social, and economic benefits of control accrue to society, costs are borne by only a few individuals and organizations. For decades, policy makers have used incentives and sanctions to encourage or coerce individual actors to contribute to the public good, with limited success. Diverse, subnational efforts to collectively manage invasive plants, insects, and animals provide effective alternatives to traditional command‐and‐control approaches. Despite this work, there has been little systematic evaluation of collective efforts to determine whether there are consistent principles underpinning success. We reviewed 32 studies to identify the extent to which collective‐action theories from related agricultural and environmental fields explain collaborative invasive species management approaches; describe and differentiate emergent invasive species collective‐action efforts; and provide guidance on how to enable more collaborative approaches to invasive species management. We identified 4 types of collective action aimed at invasive species—externally led, community led, comanaged, and organizational coalitions—that provide blueprints for future invasive species management. Existing collective‐action theories could explain the importance attributed to developing shared knowledge of the social‐ecological system and the need for social capital. Yet, collection action on invasive species requires different types of monitoring, sanctions, and boundary definitions. We argue that future government policies can benefit from establishing flexible boundaries that encourage social learning and enable colocated individuals and organizations to identify common goals, pool resources, and coordinate efforts.

Invasive terrestrial plants globally threaten agricultural and natural systems. Prolific dispersal mechanisms enable "weeds" to colonize across ownership boundaries, constituting a collective action problem where effective control requires contributions from multiple actors. Researchers have long recognized the cross-boundary nature of weed control, yet most studies have focused on whether actor-specific characteristics, such as sociodemographics and cognition, influenced individual weed control behaviors. More recent work has begun to explore the drivers of communal control efforts, i.e., cooperatives, group actions. Few studies have empirically investigated how the collective aspects of weed invasions influence individual control behaviors. Here we provide quantitative evidence of a relationship between collective aspects of the weed control problem and landowners' willingness to engage in individual weed control efforts. In a mail-back survey of Montana landowners (n = 1327) we found collective factors, such as injunctive norms and the belief that weeds are a cross-boundary problem, were significantly correlated with willingness to engage in three different weed control behaviors. Each behavior was correlated with a unique suite of collective factors suggesting that successful interventions must be behavior-specific. These results add to a growing body of evidence that the collective nature of invasive species control is critical for understanding human behavioral responses.

Conserving large carnivores while keeping people safe depends on finding means for peaceful coexistence. Although large carnivore populations are generally declining globally, some populations are increasing, causing greater overlap with humans and increasing potential for conflict. One method of reducing conflict with large carnivores is to secure attractants like garbage and livestock. This method is effective when implemented; however, implementation requires a change in human behavior. Humanwildlife interaction is a public good collective action problem where solutions require contributions from many and individual actions have effects on others. We used the collective interest model to investigate how individual and collective factors work in concert to influence landowner attractant securing behavior in Montana, USA, in black (Ursus americanus) and grizzly bear (U. arctos) range. We used data from a mailback survey to develop logistic regression models testing the relative effects of collective and individual factors on landowners' attractant securing behaviors. The most important factor was whether individuals had spoken to a wildlife professional, a reflection of social coordination and pressure. Other collective factors (e.g., social norms [i.e., expectations and behaviors of peers] and the existence of discussion networks [i.e., how much social influence an individual has]) were equally important as individual factors (e.g., beliefs, age, gender) for influencing attractant securing behavior among Montana landowners. This research suggests pathways for wildlife managers and outreach coordinators to increase attractant securing behavior by emphasizing collective factors, such as social norms, rather than appealing exclusively to individual factors, such as risk perception of large carnivores. Furthermore, wildlife agencies would be justified in increasing their efforts to connect with landowners in person and to connect with members of the public who play an important role in discussion networks. This research demonstrates that, even on private lands, collective interests may be a missing and important piece of the puzzle for encouraging voluntary attractant securing behavior and improving wildlife-human coexistence.