Uncovering the vertebrate scavenger guild composition and functioning in the Cerrado biodiversity hotspot

Résumé

Scavenging is widespread among vertebrates, being very important for maintaining certain ecosystem functions. Despite this, the scavenger communities remain poorly known in some biomes, especially in the Neotropics. Our main objective was to describe for the first time the scavenger community and identify the factors affecting scavenging efficiency in the Brazilian Cerrado. We analyzed the effects of vegetation cover, time of carcass placement and carcass weight, on scavenger species richness, individual abundances, carcass detection and consumption times, and carcass consumption rate. We monitored 11 large and 45 small carcasses using automatic cameras. We documented a total of 19 vertebrate scavenging species, four species of vultures and 15 facultative scavengers. We found that carcass size was the most important factor affecting the scavenger assemblage and consumption patterns. Large carcasses were dominated by vultures, whereas small carcasses were consumed mainly by facultative scavengers. We also found differences between large and small carcasses in all carcass consumption variables except for detection time. However, we did not find an effect of vegetation cover or time of carcass placement on scavenging patterns. The negligible role of mammals and non-raptor birds in large carcasses is also noteworthy, probably due to the consumption and foraging efficiency of the vultures, and the more frugivorous habits of the mesocarnivores. Our results show a highly diverse and efficient scavenging vertebrate community in the Brazilian Cerrado, and the need to preserve them in the face of the significant habitat transformations suffered by this biodiversity hotspot.