Carlos Botelho

Carlos Botelho State Park is a protected area covering approximately 37,644 hectares in the southern Vale do Ribeira region of São Paulo state, Brazil. ^[1] Located in the municipalities of São Miguel Arcanjo, Capão Bonito, and Pilar do Sul, the park preserves one of the most extensive tracts of lowland and submontane Atlantic Forest remaining in São Paulo state. It forms part of the Atlantic Forest South-East Reserves, a UNESCO World Heritage Site inscribed in 1999, and shares boundaries with the larger Intervales State Park, together creating an important Atlantic Forest wildlife corridor. ^[2] The park was named after Carlos Botelho, a former São Paulo Secretary of Agriculture (1904–1908) who was instrumental in early forest conservation in the state. ^[1]

Carlos Botelho is renowned for harboring one of the largest and healthiest populations of woolly spider monkeys (southern muriquis, Brachyteles arachnoides) in the world, with studies documenting the park holding more than half of the entire Brazilian population of this species. ^[1] Long-term population monitoring has been conducted by Brazilian and international primatologists since the 1980s. Brown howler monkeys, tufted capuchins, and black lion tamarins (Leontopithecus chrysopygus) have also been documented in the park. ^[2] Tapirs, pumas, ocelots, and giant anteaters are present. The avifauna exceeds 300 species, including numerous Atlantic Forest endemics. The park is a recognized Important Bird Area.

The forest of Carlos Botelho represents lowland and submontane dense ombrophilous Atlantic Forest in exceptional condition, with a closed canopy reaching 25–35 metres and a complex stratified structure including emergent trees, subcanopy, shrub layer, and dense herbaceous layer. The flora is extraordinarily diverse, with hundreds of tree species per hectare, and exceptionally rich communities of epiphytic orchids, bromeliads, ferns, and mosses. Palms including Euterpe edulis (juçara palm) are abundant and support frugivorous wildlife. The park also contains patches of restinga forest at lower elevations near the Ribeira valley. The floristic composition is characteristic of the interior Atlantic Forest with significant regional endemism.

Carlos Botelho occupies part of the southern extension of the Serra de Paranapiacaba, a mountain range forming the drainage divide between the coastal Ribeira River system and the Paranapanema River draining to the Paraná basin. The underlying geology is composed of Precambrian metamorphic and igneous rocks — primarily gneisses, schists, and granitoids — of the Ribeira Belt, formed during the Brasiliano orogeny approximately 600–700 million years ago. The terrain is dissected by numerous streams and rivers draining into the Ribeira de Iguape River, which flows to the sea through one of the largest estuaries in the South Atlantic. The deeply weathered tropical soils support the extraordinarily productive rainforest vegetation.

The park experiences a humid subtropical climate with warm, wet summers and cooler, less rainy winters, though rainfall occurs in all months. Annual precipitation ranges from 1,400 to 1,800 mm, with the peak rainfall from November to March associated with the South Atlantic Convergence Zone. Mean temperatures range from 17°C in the coolest months to 25°C in summer at lower elevations, with highland areas remaining cooler. The high moisture content of the atmosphere supports the dense epiphyte communities that are characteristic of the Atlantic Forest in this region. Occasional cold fronts from the south bring brief temperature drops but frost is rare at the elevations occupied by the park.

The Vale do Ribeira region was inhabited by Tupinambá coastal groups and interior Jê-speaking peoples at the time of Portuguese contact. The Ribeira de Iguape River corridor became one of the first colonial agricultural zones in São Paulo state, producing gold, rice, and later bananas. The rugged interior of the Serra de Paranapiacaba remained largely inaccessible to colonists and provided refuge for indigenous peoples displaced from the coast. The region was settled by a mix of Portuguese colonists, freed enslaved Africans who established quilombola communities, and indigenous remnant groups — making the Vale do Ribeira one of the most culturally diverse regions in São Paulo state, with recognized quilombola territories adjacent to the park.

Carlos Botelho State Park was established on 10 September 1982, through the merger of several forest reserves maintained by the São Paulo state government since the early 20th century, including the São Miguel Arcanjo Forest Reserve established in 1941. ^[1] The creation of the park formalized protection of forests that had been managed as state reserves for decades, providing stronger legal protection and a management framework. Scientific interest in the park intensified following studies of its exceptional muriqui population, which catalyzed long-term research programs. The park was incorporated into the UNESCO Atlantic Forest South-East Reserves World Heritage Site in 1999. ^[2]

Carlos Botelho offers several trail circuits through undisturbed Atlantic Forest, making it an outstanding destination for birdwatching and wildlife observation. The Trilha do Corisco (Lightning Trail) is a moderately challenging circuit through tall lowland forest with excellent opportunities to encounter muriquis, brown howler monkeys, and forest birds. The Trilha das Bromélias (Bromeliad Trail) passes through forest sections with exceptional epiphyte diversity. The park's streams offer refreshing natural swimming pools during the warm season. The primary draw for serious wildlife enthusiasts is the chance to observe muriquis — which are habituated to researchers and guides in some areas — feeding and moving through the high forest canopy.

The park's main entrance is located near São Miguel Arcanjo, accessible via the SP-139 highway connecting Capão Bonito to the Anchieta highway (SP-150). The park operates a visitor center with interpretation materials, restroom facilities, and picnic areas near the main entrance. Camping is available in designated areas within the park. The city of Registro, approximately 60 kilometres to the south, serves as a regional hub for the Vale do Ribeira with accommodation options. São Paulo city is approximately 200 kilometres northeast via the Anchieta highway. Guided trail access is required during peak periods, and prior registration with the Fundação Florestal (managing agency) is recommended.

Carlos Botelho's most significant conservation achievement is the long-term maintenance of viable muriqui populations in highly threatened Atlantic Forest, demonstrating the value of state park protection in stemming biodiversity loss. The park forms a core component of the UNESCO Atlantic Forest South-East Reserves World Heritage Site, recognized for its outstanding universal value as one of the world's most species-rich terrestrial ecosystems. ^[1] Ongoing threats include illegal logging in adjacent private lands that reduces habitat connectivity, poaching of palm hearts (juçara palm extraction), and fire from agricultural burning in surrounding areas that occasionally enters the park during drought years. The park participates in the São Paulo Atlantic Forest Connectivity Program, which supports restoration of forest corridors between protected areas.