Introduction
Wild primate predation has been widely reported for various Neotropical cat species. Apparently, prey body size and predator body size are related, with large cats preying mainly on large primates. Remains from different species of primates have been observed in scats of different Neotropical cat species (Table 1). According to Cabrera and Yeppes (1940), primates are the favorite prey of Puma yaguaroundi in some regions of Central America. More recently, Miranda et al. (2005), found fingers and nails from Alouatta guariba clamitans in two fecal samples from Leopardus pardalis and suggests that the ocelot may be a potential predator of all Neotropical primates.
In this study, we focus on a hunting technique by the margay, Leopardus weidii. Morphologically, margays have arboreal adaptations, but there are no published reports of the predation strategy of wild margays. The few studies on the margay suggest that its diet is mainly composed of arboreal mammals. Mondolfi (1986) analyzed the stomach contents of margay from Venezuela and found remains of squirrel (Sciurus granatensis) and the wedge-capped capuchin monkey (Cebus olivaceus-cited as nigrivittatus, a junior synonym). Margay prey species in Guyana were also arboreal mammals (Beebe 1925). In captivity, margays were observed preying on Saguinus niger (Oliveira, 1998).
Table 1.
Review of primates predated by Neotropical cat species.

In the course of our field research on felids, we interviewed local Amazon jungle inhabitants (woodsmen and mestizo Indians) in different regions of central Amazonia to learn about the biodiversity of local habitats, and in particular, the natural history of Neotropical cat species, including their prey capture techniques. Interestingly, several of the interviewees described a common predation strategy by Neotropical cats as attracting their prey by mimicking the prey species' vocalizations. More than a dozen reports of Puma concolor, Panthera onca and Leopardus pardalis mimicking vocalizations of agoutis (Dasyprocta spp.), tinamous or nambus (Crypturellus sp.) and solitary tinamous or macucos (Tinamus sp.) were made in different river basins (Madeira, Juruá and Purus) (Table 2). Until now, no scientific observations of this type of behavior have been published for Neotropical felids. Here we report the first field observation of margay mimicking behavior, recorded during field research on the primate pied tamarin (Saguinus bicolor) at the Reserva Florestal Adolpho Ducke (59 56′ 15,71556″ W, 02 56′ 25,75037″ S) in Manaus, Brazil (for a description of the area, see Ribeiro et al., 1999). In this brief report we suggest that L. wiedii uses a mimicking strategy to capture its prey. Our record confirms the reliability of the information provided by the local Amazonian inhabitants.
On October 12, 2005, at 9:13 am, a group of eight pied tamarins monitored by telemetry was feeding in a Moraceae (Ficus sp.). A large vine at 15 meters height connected the surrounding trees to the fig tree. At 9:18 am, a margay attracted the attention of a tamarin sentinel (Gordo et al., 2005) by producing calls similar to those emitted by pied tamarin pups. The adult male sentinel climbed up and down the tree to investigate the calls coming from behind the liana tangles. It assumed a surveillance position and, using specific calls, warned the group about the foreign calls. At 9:22 am we observed movements in the vine and keep hearing the call imitations. At 9:29 am three pied tamarin individuals were feeding on Ficus sp. while the tamarin sentinel was keeping surveillance. At 9:40 am, four pied tamarins climbed up and down the Moraceae in response to the repeated aggressive calls from the tamarin sentinel. At that moment, was observed a cat with small body but big feet, huge eyes and a long tail walking down the trunk of a tree (like a squirrel); it quickly jumped to a liana that was connected to the fig tree and moved toward where the tamarins were feeding, about 15 meters away. At this moment, the sentinel emitted a high scream as the predator approached the group; and the group fled immediately.
In our observations, the strategy used by Leopardus wiedii to imitate its prey was not effective in catching Saguinus bicolor. However, we suggest that this strategy is very effective in attracting prey, facilitating the attack and reducing energy expenditure during a possible pursuit. Curiously, all the potential prey (agoutis, macucos, and nambus) cited by the Amazonian inhabitants produce extremely acute vocalizations, which possibly match the potential repertoire of felines. In addition, all the aforementioned potential prey species use vocalizations in intra-specific territorial demarcation. This increases the cats' chance of success in attracting prey by imitation.
Table 2.
Reports of mimicking vocalizations of Puma concolor, Panthera onca and Leopardus pardalis.

Acknowledgments
We thank INPA (Instituto Nacional de Pesquisas da Amazonia) for permission to carry out fieldwork at the Reserva Florestal Adolpho Ducke. The observations reported here were made during a study supported by grant from PROBIO - MMA but we also wish to thank CNPq to provided financial support to Fabiano Calleia and the Wildlife Conservation Society (WCS) and Conservation Leadership Program (CLP) for provided financial support to Fabio RÖhe. We are deeply indebted to several collaborators for their inestimable help in the fieldwork (Projeto Sauim-de-Coleira) supported by PROBIO/MMA, FNMA/ MMA, WCS, CI, Durrell Wildlife Conservation Trust Apenheul Primate Conservation Trust, Shaldon Wildlife Trust, La Palmyre Zoo, Newquay Zoo, and Philadelphia Zoo. We thank M. Benchimol for comments in the manuscript and B. G. Luize for the interview in Purus River.