Reassessing distribution and population estimates of the golden-headed lion tamarin Leontopithecus chrysomelas (Primates, Callitrichidae)

Résumé fourni par la source

The golden-headed lion tamarin (GHLT) Leontopithecus chrysomelas is an endangered primate endemic to the Brazilian Atlantic Forest that faces intense pressure from habitat loss and degradation. Between 2018 and 2022, we surveyed GHLT populations across their distribution to determine the current extent of occurrence (limits of where they can be found) and population size. Using field results and geospatial modeling, we determined an extent of occurrence of 13215 km2 with a population size of 13743 to 24401 individuals. Our results reveal a worsening status for GHLT when compared to 30 yr ago, with the extent of occurrence falling by 42% and population numbers by 59%. While previously restricted by major landscape features such as rivers and changes in high-altitude vegetation, their distribution is now constrained by the scarcity of forested areas. In addition to calculating the extent of occurrence, we determined the current area of occupancy (amount of land cover used) at 395450 ha, with only 4% occurring in the western half of the extent of occurrence and just 8% protected. Conversion, degradation, and selective felling of shade trees in cacao plantations (‘cabrucas’) continue to explain the loss of GHLT in the east, but it is the steady advance of cattle ranching and agriculture in the west that is leading to many of the local extinctions. Strategies to improve the species’ conservation include the adoption of ecologically viable management practices in cabrucas by maintaining and planting new shade trees that provide food and shelter, the establishment of additional protected areas, and the development of ecological corridors via passive and active habitat restoration.

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