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As the global imperative for sustainable energy builds and with hydroelectricity proposed as one aspect of a sustainable energy profile, public discourse reflects the complex and competing discourses and social-ecological trade-offs surrounding hydropower and dams. Is hydropower “green”? Is it “sustainable”? Is it “renewable”? Does hydropower provide a necessary alternative to fossil fuel dependence? Can the ecological consequences of hydropower be mitigated? Is this the end of the hydropower era, or is it simply the beginning of a new chapter? These pressing questions circulate through discussions about hydropower in a time of changing climate, globally declining fisheries, and aging infrastructure, lending a sense of urgency to the many decisions to be made about the future of dams. The United States and European Union (EU) saw an enduring trend of dam building from the Industrial Revolution through the mid-1970s. In these countries, contemporary media discussions about hydropower are largely focused on removing existing hydropower dams and retrofitting existing dams that offer hydropower potential. Outside of these contexts, increasing numbers of countries are debating the merits of building new large-scale hydropower dams that, in many developing countries, may have disproportionate impacts on indigenous communities that hold little political or economic power. As a result, news and social media attention to hydropower outside the United States/EU often focus on activist efforts to oppose hydropower and on its complex consequences for ecosystems and communities alike. Despite hydropower’s wide range of ecological, economic, and social trade-offs, and the increasing urgency of global conversations about hydropower, relatively little work in communication studies explores news media, social media, or public debate in the context of hydropower and dam removal. In an effort to expand the scope of communication studies, after reviewing existing work the attention here shifts to research focused more broadly on human dimensions of hydropower. These dual bodies of work focus on small and large dams from Europe to the Americas to Asia and have applied a range of methods for analyzing media coverage of the hydropower debate. Those studies are reviewed here, with an emphasis on the key themes that emerge across studies—including trust, communication, local engagement, and a call to action for interdisciplinary approaches, intertwined with conflict, conflict resolution, and social and ecological resistance. The conclusion offers an original case brief that elucidates emerging themes from our ongoing research about hydropower and dam removal in the United States, and suggests future directions for research.

Cognition and learning have been widely studied in vertebrates, but not across much phylogenetic breadth. Non-avian reptiles, for example, have been poorly studied. Anecdotal observations and a few previous studies suggest that lizards may have strong cognitive skills owing, in part, to behaviors such as optimal foraging and territoriality. We tested four lizard species, including three species of monitor lizard (Varanus spp.) and one species of beaded lizard (Heloderma), in a longitudinal, repeated-trials experimental design using a puzzle-feeder device to evaluate learning, in the form of latency trends over time. We used a Bayesian multilevel modeling statistical method and incorporated unsuccessful trials as censored data. Collectively, all lizards showed a pattern of decreasing latencies over time. We interpret this pattern as learning among our lizards. Notable individual and inter-specific differences were evident, however, suggesting that learning abilities differed among the lizards. In this case, the monitor lizards exhibited steeper declines in latencies and greatly reduced inter-individual variation in comparison to the beaded lizards. Finally, we found differential use of the claws versus the snout among the lizards, which is consistent with a previously posed hypothesis based on different species than we measured.