IN THE PROTECTED AREA PENÍNSULA VALDÉS: ARE GUANACOS WHERE THEY WANT OR WHERE THEY CAN?

MARCELA NABTE; ANDREA MARINO; VIRGINIA BURGI; SERGIO SABA

Mendoza

Congreso; 10th International Mammalogical Congress; 2009

CONICET, IADIZA, SAREM

The guanaco (Lama guanicoe) population has declined during the last century as a result of human activities. Competition with sheep for forage, poaching and habitat degradation are the main activities responsible for its decrease. In Península Valdés (PV) Protected Area there are more than 80 private ranches with sheep rearing as the only activity being developed, whereas few ranches also carry out an alternative activity to wool production (e. g. tourism). The objective of this study was to describe the relationship between guanaco and sheep abundances, and their responses to the paddock size, paddock primary productivity and management (sheep rearing or sheep rearing/tourism) in PV. Surveys consisted in counts of the number of guanacos detected from the roads. Interviews to ranch residents were conducted to obtain sheep abundance per paddock and its management. Paddock sizes were obtained from digitalized maps, and Enhanced Vegetation Index (EVI) derived from MODIS satellite images was used to estimate paddock primary productivity. Our results showed: 1) an inverse relationship between primary productivity and paddock size, 2) sheep densities were higher in more productive (smaller) paddocks, 3) guanacos were more abundant in larger (poorer) paddocks in ranches where the main activity was sheep rearing; with the exception of those ranches where livestock production was combined with other management practices. The positive relationship between guanaco abundance and paddock size in sheep-rearing ranches could be the result of lower exposure to poaching through reduced access from the roads and/or increased stocking rates imposed by profitability restrictions in smaller ranches. Alternative activities combined with traditional practices, which have been suggested to improve incomes in small ranches, seem to favor guanaco occurrence in PV Protected Area.