South American dogs
Though C. familiaris, which co-evolved along with humans in Eurasia, is found early in the archeological record of North America, probably as a result of Bering Strait crossings, they arrive much later in South America. Dogs are reported from 4,5 kya in Ecuador and the coast of Peru (Stahl 1984; Salomon and Stahl 2008; Stahl 2012), and up to 10 kya in other parts of the Americas (Allison et al. 1982; van Asch et al. 2013, Perri et al. 2018).
It seems most probable that any dog present in Chile arrived along migratory or trade routes from the Andes, with the earliest evidence of dogs in the form of artistic representations from cultures such as the Moche (1900 ya – 1300 ya) or the Chimú (1100 kya – 500 ya) (Vásquez Sánchez et al. 2009). Prates et al. (2010) hypothesize that the presence of dogs in South America was mainly related to complex societies, such as the Andean societies of Peru and Ecuador previously mentioned, and that their arrival in the Southern Cone is related to an increase in long-distance communication and trade by egalitarian hunter-gatherer societies of the Pampas and Patagonia. The authors come to these conclusions based on archaeological deposits in northern Argentina dating from around 1000 ya (around 500 years before the arrival of the Spanish), which accords with other archaeological evidence of early dog presence in southern Brazil (1600 ya, Guedes Milheira et al. 2017) and in Uruguay (undated remains, but found in multiple-use structures starting around 1000 ya, López Mazz et al. 2018).
Many morphotypes of dogs may have been present in South America at different times. Gilmore (1950) lists nine possible breeds of South American dogs, remarking that parallel selection pressures or morphological constraints resulted in a terrier-like dog (the Fuegian dog), a setter-like dog (the Ona dog), a foxhound/greyhound type dog (the Tehuelche dog), and another terrier-like dog (the Techichi dog), as well as hairless dogs. The Pre-Columbian origins of these possible breeds is unknown. Van Asch et al. (2013) confirmed the pre-Columbian origins of several formally recognised American breeds, including the Peruvian perro sin pelo (“hairless dog”). Vásquez Sánchez et al. (2009) summarize many possible morphotypes of South American dogs, including a short-nosed dog from the Chicama valley, the medium-sized “helping dog”, the “pet” dog with a long body and short limbs, the miniature dog similar to a chihuahua, the hairless dog, a short-haired dog, a Peruvian bulldog, a Peruvian sausage dog, a long-haired Incan dog, and the Chiribaya shepherd used to herd llamas. Vásquez Sánchez et al. (2009) also discuss dogs depicted on Moche pots, including a morphotype consisting of a small or medium-sized spotted dog with a bulbous head, which appears in a deer-hunting scene among other contexts. They speculate that this kind of dog might have been used to corner deer during hunting. Like the Peruvian pitbull (Cossios E. 2018), many morphotypes may have been bred locally for certain periods of time, but later allowed to outcross with other morphotypes.
It is unclear whether prehispanic dogs of South America would have formed significant feral populations, although large packs of feral dogs are reported by the 18th century (Prevosti et al. 2015), and it is hypothesized that feral populations existed soon after the beginning of dog domestication in Eurasia (Boitiani & Ciucci 1995). Dogs, when feral or free ranging, are omnivorous opportunists (Campos et al. 2007). Dogs that are fed by humans tend to predate much less on wild prey (Vanak & Gompper 2009). This indicates that, if there were either feral or free-ranging dogs in South America before the arrival of the Europeans, the pressure against succeptible wildlife may have a reasonable historical depth, although maybe not enough to allow prey to evolve adequate anti-predator behaviours.