Demography, health and reproductive status of introduced red deer in Patagonia, Argentina

SMITH-FLUECK, JM; FLUCK, WT

Buffalo, New York, USA

Conferencia; The Wildlife Society 5th Annual Conference; 1998

The Wildlife Society

Densities of introduced red deer (Cervus elaphus) are believed to be increasing rapidly throughout many areas of Patagonia while quality of trophies has decreased in recent years. We suspect that some populations will soon reach the high point of the eruptive phase following their liberation. On an 80,000 hectares study area in northwestern Patagonia, data was collected in 1996-97 to determine if the apparent high population density is affecting the health and reproductive success of females. From females collected and aged in spring and autumn, we determined the rate of reproduction to be 100% for females 2.5 yrs or older whereas only 11% for yearlings (n=43). In autumn, data from collected females and road surveys (n=1284) revealed 52 and 49 calves/100 females≥1.5 years-old, respectively. Conception was centered on March 22 (STD±10 days). The sex ratio for 17 fetuses was 1:1. Kidney fat deposits were 7.4% in November indicating that food may be limited. Yet pathological symptoms were low. Only low levels of Fasciola hepatica and no ectoparasites were found (the digestive system was not analyzed). Two individuals showed morphological aberrations and another animal with systemic lesions appeared to have tuberculosis although histopathological analyses were negative. In March there were 46 males/100 females≥one years-old. These preliminary results suggest that the population density could continue to increase substantially before any major die-off occurs. Taking this into consideration plus the unbalanced sex ratio, the low kidney fat level, the disturbed landscape, and the interest in trophy hunting, we recommend immediate action to monitor trends in population density and to develop an adherent harvest strategy to greatly reduce the current population size, initially emphasizing removal of females.