Morro do Diabo

Morro do Diabo State Park encompasses approximately 33,800 hectares of lowland Atlantic Forest in the Pontal do Paranapanema region of extreme western São Paulo state, representing the largest continuous remnant of interior Atlantic Forest in the state and one of the most critical blocks of this biome in all of Brazil. The park takes its name from a prominent basaltic mesa—'Devil's Hill'—that rises above the surrounding agricultural landscape. It serves as the primary stronghold of the critically endangered black lion tamarin (Leontopithecus chrysopygus), a small primate found nowhere else on Earth. Surrounded by sugarcane, soybean, and cattle pastures that replaced Atlantic Forest across 95 percent of the original Pontal do Paranapanema landscape, Morro do Diabo represents an irreplaceable conservation island.

Morro do Diabo's wildlife community is exceptional both for its diversity and for harboring species extinct or extirpated across most of their former ranges. The black lion tamarin—with a global wild population of approximately 1,000 individuals—depends critically on this park and adjacent private reserves managed by the Instituto de Pesquisas Ecológicas (IPÊ). Tapirs, peccaries, giant anteaters, giant armadillos, and pumas persist as intact components of the forest food web. The park supports one of the best remaining populations of the bush dog in São Paulo state. Over 300 bird species have been recorded, including the endangered São Paulo tyrannulet, harpy eagles on rare occasion, and robust populations of forest interior specialists. The park's large mammal community functions as an ecological indicator of the forest's relative intactness.

The park's vegetation is classified as semideciduous Atlantic Forest—a transitional forest type that loses a portion of its canopy during the pronounced dry season characteristic of western São Paulo's continental interior climate. Dominant canopy trees include peroba-rosa, cabreúva, jequitibá-branco, and various species of Aspidosperma, with emergents reaching 30 meters. The forest understory is rich in native palms, particularly jerivá and bocaiúva, which serve as critical food sources for tamarins and many bird species. Lianas and epiphytes are abundant throughout the forest interior. Along stream corridors, gallery forests with denser moisture-loving vegetation provide connectivity through the landscape and support distinct plant communities. The basalt-derived soils of the Pontal region support exceptionally productive forest communities.

The Pontal do Paranapanema region rests on the Paraná Sedimentary Basin, one of the world's largest intracontinental sedimentary accumulations, underlain by the Serra Geral basalt formation. During the Cretaceous period, massive volcanic eruptions produced the thick basalt flows that now form the region's characteristic flat-topped hills and mesas. The prominent Morro do Diabo itself is a remnant basaltic plateau that erosion has isolated from surrounding tablelands. Basalt weathers to produce dark, fertile terra roxa (purple earth) soils—among the most agriculturally productive in Brazil—which drove the intensive forest clearing that now surrounds the park. The Paranapanema River forms the park's western and southern boundary, its valley cut through the ancient basalt sequence by millennia of erosive downcutting.

Western São Paulo state experiences a tropical climate with a clearly defined dry season, classified as Aw under the Köppen system. Annual rainfall averages 1,200 to 1,500 millimeters, concentrated in the October through March wet season. The dry season from June through September can bring extended droughts that stress the semideciduous forest canopy, triggering partial leaf fall that distinguishes this forest type from the evergreen forests of the coast. Summer temperatures regularly exceed 35°C, while winter nights can occasionally fall near 5°C during cold fronts from Patagonia. The continental interior location, far from Atlantic Ocean moisture influences, produces this more extreme seasonal climate compared to coastal São Paulo. Periodic drought years intensify fire risk in the dry season.

The Pontal do Paranapanema was among the last frontier regions of São Paulo state to be colonized, with significant human settlement beginning only in the late nineteenth and early twentieth centuries as coffee fazendas expanded westward from the Paulista plateau. Indigenous Kaingang communities had inhabited the region for centuries before displacement. Massive land speculation and fraudulent land grants—known locally as as terras griladas—drove chaotic occupation and deforestation across the Pontal from the 1940s through the 1970s. The Landless Workers Movement (MST) has maintained a strong presence in the region since the 1980s, establishing agrarian reform settlements on disputed lands adjacent to the park. The ongoing land reform process and its interface with conservation remains a defining social dimension of the park's context.

Morro do Diabo was first protected as a biological reserve by the federal government in 1941, but enforcement was weak and deforestation continued in surrounding areas. The São Paulo state government redesignated and expanded the protected area as a state park in 1986, strengthening management capacity and establishing the formal boundary that encompasses the current 33,800 hectares. The Associação Mico-Leão-Preto—later renamed Instituto de Pesquisas Ecológicas (IPÊ)—began systematic black lion tamarin population surveys and conservation programs in the 1980s in partnership with park authorities. International partnerships with the Wildlife Conservation Society and other institutions supported reintroduction programs that established satellite tamarin populations on private farms adjacent to the park.

The park's principal attraction for naturalists and wildlife enthusiasts is the opportunity to observe black lion tamarins in their natural habitat—an experience available only within this small corner of western São Paulo. Guided wildlife walks on the park's trail network are offered by park staff and IPÊ researchers who can reliably locate tamarin family groups. The summit of the Morro do Diabo mesa provides panoramic views across the Paranapanema floodplain and surrounding agricultural landscape, offering striking visual evidence of the forest island condition in which the park exists. Birdwatching trails through interior forest are productive for Atlantic Forest endemics. Night walks reveal nocturnal mammals including giant armadillos, tapirs, and various owl species that inhabit the park.

Morro do Diabo State Park is located near the municipality of Teodoro Sampaio, approximately 600 kilometers west of São Paulo city, accessible via the SP-613 highway. The park headquarters offers visitor registration, interpretive materials, and guided tour booking. Visitor numbers are managed to minimize disturbance to sensitive wildlife, particularly tamarin family groups. Basic accommodation options exist in Teodoro Sampaio, with no overnight facilities within the park itself. Visitors planning wildlife-focused visits should contact the park administration or IPÊ in advance to arrange guided excursions with knowledgeable naturalists. The dry season months of June through September offer the best wildlife observation conditions, as reduced foliage improves visibility within the forest.

Morro do Diabo's conservation challenges center on the profound isolation of the forest block within a heavily modified agricultural landscape, the small and genetically vulnerable black lion tamarin population, and ongoing pressure from illegal hunting, logging, and fires set along park boundaries. IPÊ's Black Lion Tamarin Conservation Program has achieved remarkable success since the 1980s, growing the global wild population from under 100 to approximately 1,000 individuals through habitat protection, reintroduction, and private landowner engagement. The establishment of ecological corridors linking the park to private forest reserves is a priority conservation strategy. Community engagement with agrarian reform settlement residents adjacent to the park focuses on reducing fire incidence and building local stewardship of the forest. Genetic management of the tamarin metapopulation across multiple reserves is coordinated internationally.