Aspects of the behavior, ecology and conservation of the Pampas deer

I studied the Pampas deer in its natural habitat in Uruguay, and in captivity in the southern and northern hemispheres. Different techniques were used, and were compared, to estimate deer density on the grassland; density on sheep-free rangelands varied from 19–53 deer/km2. Management areas containing both cattle and sheep had deer densities 1/5–1/10 as high. All estimates except “landowner interviews” suggested a population decline 1988–1994. Traditional domestic ungulate stocking rates in the area may not be sustainable.; Mean home range size of adult males was 24.9 Ha in breeding season and 39.2 Ha in birthing season. Mean home range size of adult females was 18.1 Ha in breeding season and 51.9 Ha in birthing season (significantly different). Mean dispersal distance from natal site for ear-tagged males and females was about 900 meters, approximately the equivalent of one home range unit.; Pampas deer have a mild spring birth peak; the interquartile range (middle 50%) for pampas deer births was 90 days, which is compared to blacktailed deer birth peaks (IQR = 18 days) and pronghorn birth peaks (IQR = 11 days). 67% of captive Pampas deer give birth in their second year, while fewer than 20% of eartagged, wild Pampas deer gave birth in their second year. Wild Pampas deer can develop species-typical 3-point antler sets as 1-year-olds. Large-antlered males shed velvet before medium- and small-antlered males in wild Pampas deer (IQR for all male velvet-shedding = 28 days, compared to blacktail deer velvet shedding IQR = 14 days). Livestock management and conservation law enforcement activities should take into account the relatively longer cycle of reproduction in Pampas deer.; Group size was analyzed by sex and age class in relation to deer density and habitat. Yearling males occurred in the largest Typical Group Size (TGS = 8.3) during birthing season on high-density sites, adult females in the smallest groups (TGS = 5.2). Differences between TGS of different age/sex classes were significant during the birthing season on high density sites, but not during other seasons, nor on lower-density sites.