Subsistence livelihoods depend on the ability to read and predict the environment. Perceptions of environmental change mediate potentially adaptive behaviors and are related to culture (and knowledge), society, economy and the environment, and the opportunities they provide. Indigenous people of Puerto Nario (Colombian Amazon) are ethno-climatologists who notice changes in their environment, and their adaptive capacity is linked to both deep and general knowledge of their contexts. Livelihoods are highly dependent on natural resources and are being threatened by contemporary changes. In Colombia, most of the work on climate change is done at the planning level, and does not consider local realities in a meaningful way. This dissertation seeks to translate into local realities, abstract scenarios of climate change. Using ethnographic tools (life histories, resource walks, semistructured interviews), and statistical tools (time series analysis), my goal is to understand how perceptions are influencing land use practices, creating new behavioral responses with consequences on the landscape. My objectives are to: 1) explore changes in river behavior since it is the key factor determining subsistence activities; 2) characterize local perceptions of environmental change and compare them with hydroclimatological data; 3) characterize livelihood implications of perceived changes in the environment and study the impacts of coping decisions. Results indicate that 1) environmental variables have been changing significantly in the region; 2) indigenous perceptions reflect the deep grounded knowledge that people have of their environment; and 3) livelihoods dependent on natural resources are profoundly affected by an unpredictable environment. I argue that adopted coping strategies paired with cultural transformations can reduce resilience over time. The absence of local data makes it difficult to determine trends in relevant hydroclimatic variables at local scales, and whether they are consistent with peoples perceptions. This can result in poorly grounded adaptation plans that will increase communities vulnerability. The government needs to address perceptions and design culturally sound management practices together with local communities to understand the effects of regional climate change on societies and their ability to adapt.