Dietary separation of sympatric carnivores identified by molecular analysis of scats

Abstract

We studied the diets of four sympatric carnivores in the flooding savannas of western Venezuela by analysing predator DNA and prey remains in faeces. DNA was isolated and a portion of the cytochrome b gene of the mitochondrial genome amplified and sequenced from 20 of 34 scats. Species were diagnosed by comparing the resulting sequences to reference sequences generated from the blood of puma (Puma concolor), jaguar (Panthera onca), ocelot (Leopardus pardalus) and crab-eating fox (Cerdocyon thous). Scat size has previously been used to identify predators, but DNA data show that puma and jaguar scats overlap in size, as do those of puma, ocelot and fox. Prey-content analysis suggests minimal prey partitioning between pumas and jaguars. In field testing this technique for large carnivores, two potential limitations emerged: locating intact faecal samples and recovering DNA sequences from samples obtained in the wet season. Nonetheless, this study illustrates the tremendous potential of DNA faecal studies. The presence of domestic dog (Canis familiaris) in one puma scat and of wild pig (Sus scrofa), set as bait, in one jaguar sample exemplifies the forensic possibilities of this noninvasive analysis. In addition to defining the dietary habits of similar size sympatric mammals, DNA identifications from faeces allow wildlife managers to detect the presence of endangered taxa and manage prey for their conservation.

Monitoring jaguar populationsPanthera oncawith non-invasive genetics: a pilot study in Brazilian ecosystems

“…However, in this study we had similarly high success rates for DNA extraction and PCR amplification for species, sex and individual identification from jaguar faecal samples in two areas with contrasting environmental conditions. Furthermore, species identification rates based on our previously developed method (Roques et al, 2011) were higher (70% for Serra da Capivara National Park and 81% for Caiman Ecological Refuge) than those reported for sequencing methods for faeces of the same species collected in the field (59%, Farrell et al, 2000;55%, Haag et al, 2009). The use of a single pair of Amelogenin-based primers for sex determination also proved to be reliable and a more efficient technique (73-96% success rates) than those previously reported, which were usually based on amplification of the Y-chromosome-linked sexdetermining region gene, using a combination of two pairs of conserved primers (e.g.…”

Galictis cuja (Mammalia): an update of current knowledge and geographic distribution

“…Another difficulty in diet studies is that G. cuja builds latrines, often with contribution of scats by several individuals (delibes et al, 2003), impeding study of individual diets. These difficulties can be addressed by collection of fresh scats and use of camera traps and molecular analysis (faRRell et al, 2000), or via studies based on stomach contents of carcasses, considering the relatively frequent cases of road kills of the species (pfeifeR et al, 2008;CáCeRes et al, 2010).…”

Remote collection of animal DNA and its applications in conservation management and understanding the population biology of rare and cryptic species

“…For faeces this has involved the sample being dehydrated either by air drying (e.g. pumas and jaguars: Farrell et al 2000;sheep and reindeer: Flagstad et al 1999) or alcohol treatment (e.g. chimpanzees: Constable et al 2001;baboons: Bayes et al 2000;bonobos: Gerloff et al 1999;elephants: Fernando et al 2000), frozen at -20°C (e.g.…”

“…In another example, assignment of field-collected scats to each of four sympatric Venezuelan carnivore species using mtDNA analysis, indicated that scat size overlapped considerably among species. This produced a much-altered profile of their dietary niches, which had previously been interpreted on the basis of erroneous assumptions about scat size (Farrell et al 2000).…”