Ecology of a carnivore community in a rubber/Atlantic forest landscape in the northeast of Brazil
Understanding the factors that affect the presence and distribution of carnivores in human-dominated landscapes is one of the principal goals of conservation ecology. Our research seeks to determine those factors in a carnivore community inhabiting a rubber plantation/forest landscape in northeastern Brazil. We studied the carnivores in a 4000 ha region of that landscape in Bahia, which included the 3096 ha Michelin Ecological Reserve and adjacent properties. The carnivore community included ten terrestrial species of the dog, cat, weasel and raccoon families. The jaguar was extirpated from the region in the 1950s. To study the carnivores we set up a 90 point grid with a spacing of 550 m between points in forest (F), rubber groves (R) and riparian vegetation within the rubber groves (RV). Each month we placed 30 camera traps (10 F x 10 R x 10 RV) in a trimestral random rotation, sampling each of the 90 points four times between February 2013 and January 2014. We collected data on landscape structure, fruit fall phenology, vegetation composition and structure, and prey frequency as covariates for analysis. We analyzed the frequency of carnivore species using correspondence analysis and generalized linear models (GLMs).
We registered a total of 481 carnivore events (a species detection/24 hrs) in 7954 camera days. Nine species of carnivores were registered. The only species known to be in the area but not registered by the cameras was the jaguarundi (Puma yagouaroundi). The species with highest number of events were the south American coati (Nasua nasua) (n= 207), the domestic dog (Canis lupus familiaris) (n =143) and the crab-eating fox (Cerdocyon thous) (n =79). The species with least number of events were the cougar (Puma concolor) (n = 2) and the crab-eating raccoon (Procyon cancrivorus) (n = 2). Residual deviances from GLMs indicate that in the case of the coatis, dogs and crab-eating foxes, the factor that contributes most to explain their frequencies is the type of habitat (X2=193.27, df=87, p<0.5; X2=106.78, df=87, p<0.5, and X2=68.88, df=87, p<0.5 respectively). Correspondence analysis shows that coatis are associated with forests, and foxes and dogs with rubber areas. The results of this study show that rubber agroforest landscapes can play a significant role in sustaining carnivore communities in the Atlantic forest, especially in mosaics with >20% forest cover and where native vegetation is left along the riparian corridors in the agroforestry lands.