Fire is a natural evolutionary force that shapes ecosystems and population dynamics. However, recent increases in the frequency and severity of anthropogenic fires have had catastrophic impacts on biodiversity, even in fire-prone environments. In Brazil’s Pantanal Wetland biome, 3.9 million hectares were affected by fires in 2020, leading to the mortality of an estimated 17 million vertebrates. In the Serra do Amolar region, 61.2% of the extent of eight protected areas was burned. Here, we use multi-year camera-trapping sampling between 2019 and 2022 at 50 sites and hierarchical Bayesian models to investigate terrestrial vertebrate responses to wildfires across 35 species within the Pantanal’s Serra do Amolar region. No significant direct effects of wildfires were detected. Nonetheless, five mammal (capybara, ocelot, red brocket deer, jaguar, and lowland tapir), two bird (bare-faced curassow and rufescent tiger-heron), and two reptile species (common green iguana and tegu lizard) showed a positive association between their occurrence probability and forest cover, indicating their vulnerability under future scenarios of recurrent wildfires. Additionally, the vertebrate species composition differed over the study period. In 2022, four species (undulated tinamou, jaguarundi, crab-eating raccoon, and Brazilian squirrel) were no longer detected. Among all species considered, 64% exhibited declines in relative abundance over time, with giant otters experiencing the most significant decline, while 36% showed increases. These findings raise significant concerns for wildlife conservation in the region, underscoring the need for long-term monitoring and proactive management strategies to mitigate the impacts of recurring wildfires on species abundance. We also highlight the importance of Serra do Amolar as a potential wildlife refuge, considering species resilience to a novel fire regime.

The buffy-tufted-ear marmoset (Callithrix aurita) is a small primate endemic to the Brazilian Atlantic Forest biome, and one of the 25 most endangered primates in the world, due to fragmentation, loss of habitat, and invasion by allochthonous Callithrix species. Using occurrence data for C. aurita from published data papers, we employed model selection and cumulative AICc weight (w+) to evaluate whether fragment size, distance to fragments with allochthonous species, altitude, connectivity, and surrounding matrices influence the occurrence of C. aurita within its distributional range. Distance to fragments with C. jacchus (w+ = 0.94) and non-vegetated areas (w+ = 0.59) correlated negatively with C. aurita occurrence. Conversely, the percentage of agriculture and pasture mosaic (w+ = 0.61) and the percentage of savanna formation (w+ = 0.59) in the surrounding matrix correlated positively with C. aurita occurrence. The findings indicate that C. aurita is isolated in forest fragments surrounded by potentially inhospitable matrices, along with the proximity of a more generalist and invasive species, thereby increasing the possibility of introgressive hybridization. The findings also highlighted the importance of landscape factors and allochthonous congeneric species for C. aurita conservation, besides indicating urgency for allochthonous species management. Finally, the approach used here can be applied to improve conservation studies of other endangered species, such as C. flaviceps, which is also endemic to the Brazilian Atlantic Forest and faces the same challenges.