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Castilleja, Ph.D.

Chief Program Officer, Environmental Conservation

Guillermo oversees the foundation's Environmental Conservation Program, which includes the Andes-Amazon, Marine Conservation and Wild Salmon Ecosystems areas. He also directs the development of a new strategy for the program.

Before joining the foundation in 2010, Guillermo was the executive director for conservation for World Wildlife Fund-International. He oversaw and coordinated its global conservation efforts, leading the development of global priorities for the network, overseeing implementation of its activities and monitoring progress. Prior to that, Guillermo was the organization’s vice president for Latin America and the Caribbean. For six years he was the representative for World Wildlife Fund in Mexico, where he led the development of one of the largest field programs in the organization’s network. He also worked for the World Bank and the National Wildlife Federation. 

Guillermo graduated from the National University of Mexico and received a master’s degree in forestry, a master’s degree in philosophy and a doctorate in forest ecology from Yale University.

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