METHODS
The target species
Atelocynus microtis(Appendix-Figure 1, A and B) is the only endemic species in the Amazon Biome, but with a wide distribution in the region, extending from Ecuador to Brazil (Leite-Pitman and Willians, 2011). It is considered rare, based on a low number of records by most studies during the last 30 years (Peres, 1991; Koester et al., 2008; Michalski, 2010; Blake et al., 2012; Ayure and González-Maya, 2014). However, this species seems to have been more frequently recorded previously (Grimwood, 1968). Possible reasons for its apparent reduced population size are infection by diseases acquired through contact with domestic dogs and the loss of habitat (Leite-Pitman and Willians, 2011). Atelocynus microtis is a mesocarnivorous canid with a generalist carnivore diet but also including fruit (Leite-Pitman and Williams, 2004; Blake et al., 2012; Penrose, 2019). It is solitary (Peres, 1991), usually with a diurnal activity (Leite-Pitman and Williams, 2004; Blake et al., 2012). Individuals of this species does not seem to tolerate disturbed habitats and prefer continuous primary lowland and upland forests (Michalski, 2010; Leite-Pitman and Willians, 2011; Rocha et al., 2020). This species is classified as ”Near Threatened” in the IUCN Red List of Threatened Species (Leite-Pitman and Willians, 2011).
Cerdocyon thous (Appendix-Figure 1, C and D) has the smallest distribution area in the Amazon Biome of the three species. However, it has a wide distribution in the rest of South America. It is common in the Pantanal , Atlantic Forest, Cerrado , Amazon, andCaatinga biomes, and frequently recorded in forest edges (Brady, 1979; Courtenay and Maffei, 2004). Individuals of this species have a twilight and nocturnal habits, are solitary or lives in small groups (Macdonald and Courtenay, 1996). Their diet is considered omnivorous, generalist, and opportunistic, feeding on invertebrates, small vertebrates, and even carrion, but they also frequently feed on fruits (Bisbal and Ojasti, 1980; Macdonald and Courtenay, 1996). Of the three species, C. thous can be considered the one that least depends on the forest, and being quite adapted to open environments, including human-made areas (Faria-Corrêa et al., 2009; Ferraz et al., 2010). This species is classified as “Least Concern” in the IUCN Red List (Lucherini, 2015).
Speothos venaticus (Appendix-Figure 1, E and F) is the canid with the broadest distribution in the Amazon, although it is not common where it occurs (DeMatteo and Loiselle, 2008; Guimarães et al., 2015; De Oliveira et al., 2018). In Brazil, this animal occurs in the Amazon,Pantanal , Atlantic Forest, Cerrado and Caatingabiomes, especially in humid forests and preserved riparian forests. Individuals of this species have a strong relationship with forest environments (DeMatteo and Loiselle, 2008; Michalski, 2010). However, it has also been recorded in open areas of the Cerrado (Silveira et al., 1998; Lima et al., 2015), and altered and fragmented environments in the Amazon (DeMatteo and Loiselle, 2008). Recently, its suitability for native environments in the Cerrado was confirmed (Lima et al., 2015). Speothos venaticus can be considered a hypercarnivore, feeding on small vertebrates and larger mammals such as pacas, agoutis, and even capybaras (Beisiegel and Ades, 2002; Zuercher et al., 2005). They are social animals, which may have a cooperative hunting system, but lone individuals are also frequently observed (Beisiegel and Ades, 2002; DeMatteo et al., 2011). This species is classified as “Near Threatened” in the IUCN Red List (DeMatteo et al., 2011). Its greatest threat appears to be habitat degradation.