Citizen scientists help unravel the nature of cattle impacts on native mammals and birds visiting fruiting trees in Brazil's southern Pantanal

We used 2 years of camera-trap surveys conducted by citizen scientists to compare native mammal and bird visits to dominant fruiting-tree species in low and high cattle-impact areas of rarely-flooded “cordilheira” forests in the Brazilian Pantanal. Monthly fruit censuses showed greater diversity of fruiting-tree species in low cattle-impact areas. Citizen scientists documented 29 native mammal and bird species among 5639 photo records obtained at fruiting trees. Analyses of 3 sets of camera-trap samples comprising: (1) only Attalea phalerata palms, (2) all ten dominant fruiting-tree species, and (3) all except a species with a highly-valued fruit and an unusual distribution, showed that faunal composition in low cattle-impact areas was significantly different and more diverse compared to that in high cattle-impact areas. Long-term cattle-related alterations of forest vegetation and short-term fruit depletion and interference by cattle explained faunal differences. While 5 frugivores and 1 carnivore were consistent indicators of low cattle-impact conditions, the value of 2 other frugivores (Tayassu pecari and Crax fasciolata) as indicators of cattle impact varied depending on fruit-species nutritive value, timing, and distribution. Improved cattle management is needed to prevent additional loss of forest biodiversity.