Evaluating a potentially strong trophic interaction: pumas and wild camelids in protected areas of Argentina

Abstract

Predatory interactions involving large carnivores and their ungulate prey are increasingly recognized as important in structuring terrestrial communities, but such interactions have seldom been studied in the temperate Neotropics. Here, the large carnivore guild is limited to a single species, the puma Puma concolor, native prey populations have been drastically reduced and lagomorphs and ungulates have been introduced. We examined puma dietary patterns under varying abundances of native camelid prey -guanacos and vicu˜nas -in protected areas of northwestern Argentina. We collected puma feces from seven protected areas, and sampled each area for the relative abundance of camelids using on-foot strip and vehicle transects. In one area, where longitudinal studies have been conducted, we examined the remains of vicu˜nas and guanacos for evidence of puma predation in [2004][2005][2006]. We compared our results with a study conducted in 1978-1983, and contrasted the frequency of carcasses showing signs of puma predation with estimates of camelid abundance. Across sites, we observed a positive and significant relationship between camelid consumption by pumas and camelid abundance, with pumas about nine times more likely to consume camelids where the latter were most abundant. The temporal variation in predation rates on camelids differed by species. Guanacos, which did not change in abundance between periods, showed a slight decrease (1.5 times) in the relative frequencies of individuals killed by pumas. Conversely, vicu˜nas increased in abundance by a factor of $7 between periods, coinciding with an c. 3.4 times increase in individuals showing evidence of puma predation. Some protected areas of northwestern Argentina are conserving the trophic interaction between pumas and native camelid prey. This interaction may be the basis of the far-reaching community effects described for analogous systems on other continents. It also has implications for the possible recovery of or reintroduction of camelids to areas with high puma densities, where predation losses can be expected to be high, and possibly prohibitive.

Trophic interactions between puma and endemic culpeo fox after livestock removal in the high mountains of central Argentina

“…Pumas consumed guanacos only occasionally due to the low availability of this prey, although high levels of predation (34 % ; Schneider and Aprile 2009 ) were recorded soon after reintroduction in 2007. This was also observed in other protected areas of central Argentina, where pumas prey more commonly on large prey and not on small rodents, even though the latter are more abundant (Donadio et al 2010 ) and in southern Patagonia, where guanacos are important prey for pumas (Pia and Novaro 2005 , Zan ó n Mart í nez et al 2012 ). By contrast, in southwestern Patagonia, pumas and culpeo foxes primarily consumed introduced prey species, such as the European hare, even within protected areas with a high abundance of camelids (e.g., Y á ñez et al 1986, Iriarte et al 1991, Johnson and Franklin 1994, Novaro et al 2000.…”

“…By contrast, in southwestern Patagonia, pumas and culpeo foxes primarily consumed introduced prey species, such as the European hare, even within protected areas with a high abundance of camelids (e.g., Y á ñez et al 1986, Iriarte et al 1991, Johnson and Franklin 1994, Novaro et al 2000. However, in many regions of South America, the interaction between the puma and its large prey was lost due to the drastic decline in populations of wild camelids ( > 90 % ; Donadio et al 2010 ). This was observed in southern Chile, where pumas increased hare consumption when densities of guanacos declined (Iriarte et al 1990 ) and in northwestern Patagonia, where guanacos are an ecologically extinct prey (Novaro et al 2000 ).…”

“…Several studies have concluded that both species are opportunistic and display trophic plasticity (Crespo and De Carlo 1963, Jaksic et al 1980, Iriarte et al 1990, Sunquist and Sunquist 2002. A number of studies in Argentina and Chile have focused on the ecology of each species separately (Jaksic et al 1980, Iriarte et al 1991, Johnson and Franklin 1994, Branch et al 1996, Jim é nez et al 1996, Pessino et al 2001, Donadio et al 2010 ). The only comparative studies analyzing the diet and trophic interactions of both carnivores were conducted in southern (Pia and Novaro 2005 ) and northwestern Patagonia (Novaro et al 2000 ).…”

“…Dietary responses to changes in prey abundance have been better documented in North America (Ackerman et al 1984, Iriarte et al 1990, Logan and Sweanor 2001 than in South America (Branch at al. 1996, Novaro et al 2000, Rau and Jiménez 2002, Donadio et al 2010, Zan ó n Mart í nez et al 2012. Pumas consume smaller prey and have broader diets in South America than in North America (Iriarte et al 1990 ).…”

“…This activity, coupled with intensive hunting, caused the decline and, in some cases, the local extinction of populations of medium and large native herbivores that were the main prey of native carnivores (Novaro et al 2000, Baldi et al 2001, Novaro and Walker 2005, Pia and Novaro 2005, Donadio et al 2010. The displacement of native herbivores (Guanaco Lama guanicoe , Müller 1776) by livestock (cattle, sheep, goats and horses) in central Argentina provided large and medium carnivores with food subsidies.…”