Social Ecology of the huemul at Torres Del Paine National Park, Chile

Abstract

In a ten-year study of the huemul (Hippocamelus bisulcus) population at Torres del Paine National Park in southern Patagonia, we covered a wide range of information regarding the ecology of this endanger deer. We determined the huemul social structure, social behavior, reproductive season, and associated movements throughout the year. Huemuls were observed in the park central area of Sector Grey. When animals were located, natural marks or scars, coloring of body and face, and antler characteristics were used to identify them. We also ear tagged sixteen fawns from 2002 to 2008. Behavioral information was collected from all members with focal observations. We found established and transient social groups. Among the established we found family groups, solo female, and solo male, and among the transient we found solo female, solo male, solo yearling, pair of yearlings, and mixed groups. Family groups were observed throughout the year since they remained in the same area. We observed the first mating of marked females at about 16 months of age. We were not able to determine male age of their first mating, since they left the study site as yearlings. Females gave birth from late October to mid-November. The home range varied from 269 to 336 ha for the established family group. Huemul movements were associated with seasons and reproduction cycles, which also implies group changes. During the rut, some transient solo males tried to move into home ranges of established family groups. During the birthing season, pregnant females remained alone for short periods of time, while yearlings were temporarily expelled from their natal group but remained within the home range, thus sometimes the three members of the group were seen alone. These critical periods increased antagonism among huemuls, generating changes in their group structure. Movements associated with huemul in the park consisted of movements within the home range, seasonal movements, dispersion of the yearlings, and movements during the reproductive period.

Modeling of potential habitat suitability of Hippocamelus bisulcus: effectiveness of a protected areas network in Southern Patagonia

“…3e) without recent field data observations. Once again, archeological evidence (Fernández et al 2015;L'Heureux 2016) and close sights in Chilean territory (Smith-Flueck et al 2011;Garay et al 2016), as well as oral tradition of some ranchers (e.g., Stag River ranch), support the idea that the species occurred there in the past. In this sense, the decline of huemul can be due to different human related factors (López-Alfaro et al 2012;Corti et al 2013;Briceño et al 2013) which greatly impacted the marginal huemul populations (north and southern distribution areas in the province) in those ecosystems with greater ranching activities (e.g., steppe and N. antarctica forests under silvopastoral uses).…”

Loss of Migratory Traditions Makes the Endangered Patagonian Huemul Deer a Year-Round Refugee in Its Summer Habitat

“…Yearround mean home range sizes in Tamango (Chile) were 318 ha, and similar between nonmigratory females and males [87]. For huemul reintroduced to Torres del Paine National Park, year-round home range sizes as determined during a 10-year study varied between 269-336 ha [89]. In comparison, although similar-sized mule deer (Odocoileus hemionus) are typically migratory in the Rocky Mountains, resident deer on winter ranges utilized a continuous year-long home range, displacing only some 1300 m between seasons, and shifting to just slightly higher elevations in summer [60,90].…”

“…Huemul studied in Chile over several years in three different areas showed that winter and summer range usage largely overlapped, with an insignificant mean elevational displacement of about 200 m, and thus were considered non-migratory [87]. After reintroducing huemul around 1980 to Torres del Paine National Park, some family groups remained in low-elevation areas year-round, while other individuals eventually adopted a pattern of using areas somewhat elevated (up to 150 m higher) in summer, and descending to those lower areas mainly during winter, which was also considered as non-migratory [88,89,91]. Lastly, huemul in periglacial refuge areas by the Pacific coast also had limited elevational displacement as the treeline there is only at about 400 m asl.…”

Hunting Techniques Along the Rain Shadow Gradient in North-Central Patagonia, Argentina

“…The social structure of this cervid comprises solitary male, female with or without fawn/yearlings, and family groups-up to four individuals (male, female, fawn, and yearling). Additionally, there are transient social forms, such as mixed groups (more than four individuals from both sexes and different ages during the fall/winter), yearling, and pair of yearlings, corresponding to individuals that were expelled from their birth group (Garay et al 2016;Povilitis 1978;Serret 2001). The family group usually remains in the same area, and its home range is about 3-4 km 2 (Garay et al 2016;Gill et al 2008).…”