Habitat and Ecology
Bush Dogs are reported to be a habitat generalist by indigenous peoples, within the context of occurring generally near water sources, particularly small streams, where prey densities may be higher (Zuercher et al. 2005; E.S. Lima, K.E. DeMatteo, R.S.P. Jorge, M.L.S.P. Jorge, J. Dalponte, H.S. Lima, and S. Klorfine pers. obs.; M. Swarner, pers. comm). Bush Dogs have been observed in lowland (below 1,500 m) forested habitats including primary and gallery forest (Defler 1986), semi-deciduous forest, and seasonally flooded forest (Aquino and Puertas 1997). Observations have also been recorded from cerrado habitat in Brazil (Silveira et al. 1998; Oliveira 2009, C. Brady pers. comm.) and Paraguay (Zuercher and Villalba 2002) and pampas (wet savanna) edge/riparian areas (Strahl et al. 1992, Emmons 1998). Recent reports mention Bush Dogs in three unique habitats: caatinga, chaco, and mangroves along the coast (DeMatteo and Loiselle 2008). In some cases, they have been observed several kilometers from forest habitat (Silveira et al. 1998). The species is also occasionally reported from secondary forest, ranchland (M. Swarner pers. comm.), fragmented cerrado ranchland (E.S. Lima, K.E. DeMatteo, R.S.P. Jorge, M.L.S.P. Jorge, J. Dalponte, H.S. Lima, and S. Klorfine pers. obs.; L. Silveira and A. Jácomo pers. comm.), disturbed areas (DeMatteo and Loiselle 2008, Oliveira 2009), and fragmented forest areas (Michalski and Peres 2005, Michalski 2010).
No habitat selection preference was found in either the Pantanal in Brazil (Lima, Jorge et al. 2009) or in the Upper Paraná Atlantic forest - cerrado mixture in Paraguay (Zuercher et al. 2005); however, some evidence has been found suggesting a preference for intact savanna and forest habitat versus altered (cropland and pastures) for a group of Bush Dogs in partially fragmented cerrado, indicating that habitat use and preference may differ by region and availability (E.S. Lima, K.E. DeMatteo, R.S.P. Jorge, M.L.S.P. Jorge, J. Dalponte, H.S. Lima, and S. Klorfine pers. obs.). While Michalski (2010) reported an absence of Bush Dogs in fragmented areas in southern Amazonia, others studies have demonstrated strong evidence that their occurrence is likely (DeMatteo and Loiselle 2008; Oliveira 2009; E.S. Lima, K.E. DeMatteo, R.S.P. Jorge, M.L.S.P. Jorge, J. Dalponte, H.S. Lima, and S. Klorfine pers. obs.); however, the intensity of use in these areas and impact on ecological requirements is unknown. Preliminary data from the field suggest that as the degree of habitat fragmentation increases so does the area required by Bush Dogs (E.S. Lima pers. comm.); while these data are only available for the cerrado ecosystem in Brazil, it is suspected to be true for all habitat types and a reflection of a negative relationship between prey density and habitat fragmentation. A reanalysis of the Bush Dog’s historical distribution (n > 250 locations) determined that approximately one-quarter (20%) were associated with fragmented/altered habitat and the percentage of modified habitat increased when the estimate was expanded from the area needed to support a single individual to the area to that of breeding group (DeMatteo and Loiselle 2008).
The reported variation in home range size estimates is likely associated with habitat integrity and prey density: 150 km² (Upper Paraná Atlantic Forest; Beisiegel 1999), ca. 16 km² (Beisiegel and Ades 2004), and 140 km² (Fixed Kernel 95%) for one group of Bush Dogs (n = 2–4 individuals) in cerrado (E.S. Lima, K.E. DeMatteo, R.S.P. Jorge, M.L.S.P. Jorge, J. Dalponte, H.S. Lima, and S. Klorfine, pers. obs.).
Preliminary field data supports captive studies that Bush Dogs exist in family groups with young from one or more litters (DeMatteo 2008, Michalski 2010, E.S. Lima, K.E. DeMatteo, R.S.P. Jorge, M.L.S.P. Jorge, J. Dalponte, H.S. Lima, and S. Klorfine, pers. obs.); however, solitary individuals are regularly observed in a variety of habitat types. Reproduction in the wild is aseasonal (DeMatteo 2008). The species appears to have a semi-nomadic movement pattern versus a true territory like many carnivores (DeMatteo 2008, E.S. Lima, K.E. DeMatteo, R.S.P. Jorge, M.L.S.P. Jorge, J. Dalponte, H.S. Lima, and S. Klorfine, pers. obs.) and has been recorded living in sympatry with Atelocynus microtis in Peru and Brazil (Leite Pitman, Beck et al. 2003, Michalski 2010). Estimated generation length is four years [(0.5 x reproductive length of six years) + sexual maturity at one year (in captivity; Porton et al. 1987).
Preliminary field data supports anecdotal reports of diet and the idea that Bush Dogs are highly carnivorous (Deutsch 1984, Peres 1991); however, there appears to be evidence of prey preference based on geographical region and habitat type, which is likely compounded by seasonal variability. For the Pantanal area in Brazil, the principal food item was Nine-banded Armadillo (Dasypus novemcinctus; 94%) with small mammals, Agoutis (Dasyprocta azarae), and birds occurring in smaller quantities; however, no fruit was recorded (n = 17, identified by scent and tracks; Lima, Jorge et al. 2009). For the interior Atlantic forest in Paraguay, the majority of the diet was composed of Agoutis and Paca (Cuniculus paca) with small mammals, rodents, reptiles, invertebrates, and Cecropia fruit occurring in lower amounts (n = 11, identified using mitochondrial DNA; Zuercher et al. 2005). In a successful reproduction center in southeast Brazil, where meat and fruit (banana and papaya) are available, animals eat fruit and meat in equal proportions (L. Saboia, pers. comm.). Predation of poultry has been reported to occur occasionally (DeMatteo 2008).