Current distribution and threats for an endangered population of Pampas deer (Ozotoceros bezoarticus) in Santa Fe province, Argentina.

PAUTASSO ANDRÉS; RAIMONDI VANINA; LI PUMA CECILIA; MASTROPAOLO JUAN M; CHERSICH DANIEL; SENN ADRIANA

Huilio-Huilio Chile

Congreso; 7 th. International Deer Biology Congress; 2010

Huilo Huilo Foundation - Chile; Natl. Council for Scient. Research - CONICET, Argentina

<!-- /* Font Definitions */ @font-face {font-family:Times; panose-1:2 2 6 3 5 4 5 2 3 4; mso-font-charset:0; mso-generic-font-family:roman; mso-font-format:other; mso-font-pitch:variable; mso-font-signature:3 0 0 0 1 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} span.shorttext {mso-style-name:short_text;} span.mediumtext {mso-style-name:medium_text;} span.longtext {mso-style-name:long_text;} @page Section1 {size:595.3pt 841.9pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:35.4pt; mso-footer-margin:35.4pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Pampas deer, one of eight species of Argentina’s native cervids, is considered endangered according to the Argentine red book of threatened mammals.. Nowadays, only four populations remain, which are located in Corrientes, Buenos Aires, San Luis and Santa Fe. These populations, highly isolated from each other, occur in different ecological regions. In addition, it is remarkable that Santa Fe has the smallest and most threatened Pampas deer population of Argentina. According to data collected from 1997 to 2009 in 36 field trips, we analyzed the current distribution of Pampas deer and assessed the importance of potential mortality sources using two analysis tools: 1) inspection of the areas to find indirect records, dead animal carcasses or skeletal remains and predator traces; and 2) information obtained by interviews conducted with qualified local people. In accordance with the current distribution data, a map was constructed. The distribution is limited to 500 km2 for the extent of occurrence and to a 225 km2 occupancy area. Eight areas were identified with a higher occurrence of individuals whose environmental characteristics were similar (all of them were situated close to Palo Azul - Cyclolepis genistoides - groves). We detected 30 cases of mortality, on the average 16 + 1.8 individual per year (range from 0 to 6) attributed to: poaching (63.3 %), floods (20 %) and drought (16,6%). The results for mortality distinguished by sex were: female (53.3 %), male (40 %) and two unidentified specimens (6.6 %). According to ages the results were: 90% adults, 6.6 % under one year old and 3.3% fawns under three months. Furthermore, 19 individuals were hunted, of which 57.8% were adult females and 36.8% adult males, whereas 5.2% were males under one year of age. The area where Pampas deer live in Santa Fe is one of the few natural areas in this province and the extensive cattle ranching is an economical activity that helps to preserve the Pampas deer’s environment. However, the advance of the agricultural frontier could be considered  a potential threat for this species of cervid due to the habitat change. Moreover, dwellers with more than 30 years living in the studied area mentioned diseases transmitted by cattle as another possible cause of mortality. To conclude, field data suggests that hunting could be the main threat to Pampas deer in this region, whereas flooding and drought cycles affect this population in a smaller proportion. Poaching was the main cause of death, althought it tends to decline over the period analyzed. Nevertheless, this practice has not been completely eradicated. The distribution of mortality records shows more deaths due to flooding in poorly drained areas, especially in the north. Moreover, it is important to emphasize that 84.2% of hunting episodes are concentrated in the southern part of Santa Fe. This identification of critical areas could help direct efforts to fight against each one of the main threats that endanger Pampas deer populations in Santa Fe province.