Winifred Hallwachs (born October 11, 1954) is an American tropical ecologist who helped to establish and expand northwestern Costa Rica's Área de Conservación Guanacaste (ACG).

[4] Beginning in 1985, Hallwachs and Janzen revised their work to include the restoration, expansion, and conservation of tropical dry forest through biodiversity development.

They helped found the Instituto Nacional de Biodiversidad (INBio) in 1989,[5] of which Hallwachs was a technical advisor,[6] and promoted the creation of public-private partnerships such as the Merck-INBio Agreement.

The class addressed the natural history of tropical animal-plant interactions often drawing from Janzen's research in Guanacaste, a province in northwestern Costa Rica.

Agoutis are house-cat-sized forest rodents and the guapinol is a hardwood tree whose large and hard seeds were originally dispersed by now extinct tropical megafauna.

[15] In 1985, realizing that widespread development in northwestern Costa Rica was rapidly decimating the forest in which they conducted their research, Hallwachs and Janzen expanded the focus of their work.

Their goal was to achieve tropical forest restoration, expansion (through land purchases) and conservation, while continuing their scientific research at a reduced level.

Their work at ACG is considered an exemplar of inclusive conservation,[3] which emphasizes the connections between humans and nature in one ecosystem, and the involvement of local individuals in objectives for sustainability.

[3][24][25][8] The resulting national park connects habitats from the tops of volcanoes to the sea, including mid-elevation Caribbean rainforest as well as neotropical dry forest.

There Janzen and Hallwachs met Paul Hebert, a geneticist from the University of Guelph who proposed the identification of species using mitochondrial DNA.

[2][26][22] Hebert focused on a section of 650 base pairs in the DNA sequence of the mitochondrial cytochrome c oxidase subunit I (COI) gene.

[8] Hallwachs and Janzen are also engaged in the education of local children, using the area as a "living classroom" to promote both understanding and a sense of pride and guardianship.