Culpeau

Due to conflicts with humans (i.e., preying upon poultry and livestock, Crespo and De Carlo 1963, Bellati and von Thüngen 1990, Lucherini and Merino 2008) and because of its value as a furbearer, the Culpeo has been persecuted throughout its range for many decades (Jiménez 1993, Novaro 1995). Thus, current population numbers may be the result of past and present hunting pressure and food availability. The introduction of exotic prey species such as European Hares (Lepus europaeus) and rabbits (Oryctolagus cuniculus), as well as small-sized livestock into Chile and Argentina ca. 100 years ago, probably led to increases in the distribution and abundance of Culpeos, and facilitated their expansion towards the lowlands in eastern Argentina (Crespo and De Carlo 1963, Crespo 1975, Jiménez 1993, Jaksic 1998, Novaro et al. 2000a). The recent observation that the comeback of Pumas in Patagonia may be affecting negatively its abundance suggests that a reduction of intraguild competition/predation had also favoured this expansion in range. Currently, Culpeos range over a much wider area in Patagonia than previously. Likewise, in several areas of the desert of northern Chile, recent mining activities provide the Culpeo with resources such as food, water and shelter that were in much shorter supply in the past, and hence have changed their local distribution and abundance (Jiménez and Novaro 2004).

Culpeos appear to withstand intense hunting levels as shown by fur harvest data from Argentina and still maintain viable regional populations (Novaro 1995). However, this may only be possible through immigration from neighbouring unexploited areas that act as refugia (Novaro 1995). The Culpeo population in Neuquén Province in north-west Patagonia for example, appears to function as a source-sink system in areas where cattle and sheep ranches are intermixed (Novaro 1997b, Novaro et al. 2005). Cattle ranches where no hunting occurs supply disperser foxes that repopulate sheep ranches with intense hunting. Changes in sex ratio may be another mechanism that allows Culpeo populations to withstand intense hunting (Novaro 1995). Furthermore, large litter size and early maturity (Crespo and De Carlo 1963) could explain the Culpeo's high resilience to hunting.

When hunting pressure is reduced, Culpeo populations usually can recover quickly (Crespo and De Carlo 1963). This increase was observed at the Chinchilla National Reserve (Jiménez 1993) and at Fray Jorge National Park (Meserve et al. 1987, Salvatori et al. 1999), both in north-central Chile. Culpeo densities also have increased in many areas of Argentine Patagonia following the reduction of fur prices and hunting pressure in the late 1980s and early 1990s (Novaro 1997b, Novaro and Walker 2005). An exception to this response is the Culpeo population in Tierra del Fuego, where its populations are still declining in spite of several years of reduced hunting pressure (N. Loekemeyer and A. Iriarte, in Jiménez and Novaro 2004).

Estimates from intensive trapping by Crespo and De Carlo (1963) provided a density of 0.7 individuals/km² for north-west Patagonia, Argentina. Thirty years later, Novaro et al. (2000b), using line transects, reported densities of 0.2–1.3 individuals/km² for the same area. In north-central Chile, the ecological density of culpeos in ravines was 2.6 individuals/km², whereas the crude density (throughout the study site) was 0.3 individuals/km² (Jiménez 1993). In Torres del Paine, a crude density of 1.3 individuals/km² was reported based on sightings (J. Rau, in Jiménez and Novaro 2004). Interestingly, a later estimate for the same area, based on telemetry, rendered an ecological density of 1.2 individuals/km² (Johnson 1992, in Jiménez 1993).

Based on radio telemetry, sightings and abundance of faeces, Salvatori et al. (1999) concluded that Culpeos respond numerically to a decline in the availability of their prey in north-central Chile. Earlier, based on abundance of faeces, Jaksic et al. (1993) reached the same conclusion for the same Culpeo population. In contrast, Culpeos (not distinguished from sympatric Chillas) did not show a numerical or a functional response during a decline of their main prey at another site in north-central Chile (Jaksic et al. 1992).