The Pampas deer (Ozotoceros bezoarticus) is a species of deer that live in the grasslands of South America at low elevations. They are known as in Portuguese and as or in Spanish. It is the only species in the genus Ozotoceros.
Their habitat includes water and hills, often with winter drought, and grass that is high enough to cover a standing deer. Many of them live on the Pantanal wetlands, where there are ongoing conservation efforts, and other areas of annual flooding cycles. Human activity has changed much of the original landscape.
They are known to live up to 12 years in the wild, longer if captive, but are threatened due to over-hunting and habitat loss. Many people are concerned over this loss, because a healthy deer population means a healthy grassland, and a healthy grassland is home to many species, some also threatened. Many North American birds migrate south to these areas, and if the Pampas deer habitat is lost, they are afraid these bird species will also decline. There are approximately 80,000 Pampas deer total, with the majority of them living in Brazil.
Taxonomy and evolution
Fossil records indicate that New World deer traveled to South America from North America as part of the Great American Interchange around 2.5 million years ago, following the formation of the Isthmus of Panama. They rapidly evolved into different species, with only a few surviving today. Due to the large continental glaciers and the high soil acidity in areas where there were no glaciers, a huge part of the fossil record has been destroyed, so there is no indication of what these early New World deer looked like. Fossil records begin with clear differentiation and are close to what they look like now. The Pampas deer evolved as plains dwellers; their direct ancestor first appeared during the Pleistocene epoch.
The deer may have evolved without culling predators because when alarmed, they stamp their feet, have a particular trot and whistle, and deposit odor. Pampas deer have a similar gene pattern to the related marsh deer of the genus Blastocerus, having two fused chromosomes.
There are five recognised subspecies: O. b. bezoarticus - eastern and central Brazil, south of the Amazon river into Uruguay O. b. arerunguaensis - northwestern Uruguay O. b. celer - southern Argentina O. b. leucogaster - southwestern Brazil, southeastern Bolivia, Paraguay, and northern Argentina O. b. uruguayensis - eastern Uruguay
Pampas deer are among the most genetically polymorphic mammals. Their current high nucleotide diversity shows that they had very large numbers in the recent past.
Physical characteristics
Pampas deer have tan fur, lighter on their undersides and insides of legs. Their coats do not change with the seasons. They have white spots above their lips and white patches on their throats. Their shoulder height is in females and in males. Their tails are short and bushy, 10 cm to 15 cm long, and when they run, they lift their tail to reveal a white patch, just like white-tailed deer.
Adult males typically weigh , but have been documented up to , and females typically weigh . They are a small species of deer, with relatively little sexual dimorphism. Males have small, lightweight antlers that are 3-pronged, which go through a yearly cycle of shedding in August or September, with a new grown set by December. The lower front main prong of the antlers is not divided, but the upper prong is. Females have hair whorls that look like tiny antlers stubs. Females and males have different stances during urination. Males have a strong smell secreted from glands in their back hooves that can be detected up to 1.5 km away. Compared to other small ruminants, the males have small testicles relative to their body size.
Biology and behavior
In Argentina, the mating season is December to February. In Uruguay, the mating season is February to April. Courtship behavior is submissive, such as low stretching, crouching, and turning away. The male initiates courtship with a low stretch. He makes a soft buzzing sound. He nuzzles the female and may flick his tongue at her, and averts his eyes. He stays near her, and may follow her for a long time, smelling her urine. Sometimes the female responds to courtship by lying on the ground.