A new population of Darwin's fox (Lycalopex fulvipes) in the Valdivian Coastal Range

Abstract

FindingsDarwin's fox (Lycalopex fulvipes Martin, 1837) is an en-demic of the temperate forests of the Coastal Rangeof southern Chile, that was reported by Charles Darwinin 1834 in southern Chiloe Island (42° S, 74° W; Martin1837). Initially known exclusively from that island, itwas considered both an insular subspecies of the chillafox (Lycalopex griseus Gray, 1837) (Housse 1953; Clutton-Brock et al. 1976) and a valid species (Martin 1837; Gay1947; Osgood 1943). In 1990, a mainland population wasreported at Nahuelbuta National Park (ca. 450 km northof Chiloe Island, 37° 47′ S, 72° 59′ W; Figure 1a) in sym-patry with the chilla and culpeo foxes (Lycalopex culpaeusMolina, 1782) (Jaksic et al. 1990; Medel et al. 1990; Jimenezet al. 1991). This supported its status as a valid spe-cies, later confirmed through genetic studies (Yahnkeet al. 1996). Though this canid uses diverse habitat types,it is highly associated with native forest (Medel et al. 1990;Jimenez et al. 1991; Jimenez 2007). The current popula-tion size is not precisely known, but it has been estimatedto be fewer than 600 individuals, 90% of them on ChiloeIsland (Jimenez and McMahon 2004; Jimenez et al. 2008).In light of its small population size and the vulnerabilityof remaining populations, Darwin's fox was classifiedas Critically Endangered (CR: C2a (ii); cf. IUCN 2012).The discontinuous distribution of Darwin's fox, however,raised questions regarding the existence of other popula-tions in under-explored intermediate areas (e.g., Vila et al.2004; Jimenez et al. 2008). Recently, Vila et al. (2004)genetically identified a Darwin's fox skin from PuntaChanchan (39° 21′ S, 73° 14′ W) and reported possiblesightings by local people there and at Fundo Chaihuin(40° 01′ S, 73° 25′ W), but failed to find evidence of livingindividuals. An additional dead individual was reportedfrom the nearby locality of Lastarria (Gorbea district,39° 11′ S, 72° 6′ W; D'Elia et al. 2013). These localitiesare halfway between the previously known populations(Figure 1a), suggesting that indeed the range is less dis-continuous than was previously suspected.Here we report camera-trap (Bushnell Trophy Cam,Bushnell Corporation, Overland Park, KS, USA) recordsof Darwin's foxes in three different protected areas inLos Rios region, which indeed confirm the existenceof an intermediate population (Figure 1b,c). These re-cords were obtained as part of two independent studiesand a monitoring program. One of the studies and themonitoring program were conducted in the ValdivianCoastal Reserve (VCR; 40° 02′ S, 73° 35′ W; 50,250 ha;Figure 1b) during February to May 2012 and throughout2012, respectively. The third study surveyed two pro-tected areas (Figure 1b): Oncol Park (ONC; 39° 42′ S,73° 18′ W; 753 ha; March to May 2012) and AlerceCostero National Park (ACP; 39° 59′ S, 73° 28′ W;24,694 ha; December 2012 to March 2013).We recorded Darwin's fox in nine different cameratraps (i.e., one or more photos per camera trap), three ineach protected area (Figure 1c,d,e). Records from ONCcame from transects within the park or close to itsborder, whereas records from ACP came from the high-est elevation within the park. In all these cases, photoswere obtained in areas of either old-growth forest ordense understory, with cameras that were baited withraw chicken and commercial lures (Minnesota BrandBobcat Urine, Caven's Violator-7 and Terminator lures;Minnesota Trapline Products Inc., Pennock, MN, USA).All records from the VCR came from cameras set in anarea located close to ACP, including native forests andeucalyptus plantations with dense understory (Figure 1b).We did not use lures in the VCR.Our records add to the skin reported from PuntaChanchan (Vila et al. 2004) and the parallel report of adead individual at the nearby locality of Lastarria (D'Elia