Pampas Deer Ozotoceros Bezoarticus Research Articles

New populations of pampas deer Ozotoceros bezoarticus discovered in threatened Amazonian savannah enclaves

AbstractThe savannah enclaves (i.e. patches) in the southern Brazilian Amazonia are among the most threatened and poorly surveyed sites in Amazonia. As part of an extensive mammal survey, we set camera traps in three of these savannah enclaves. We obtained 23 independent records of pampas deer Ozotoceros bezoarticus, a medium sized Neotropical cervid that is strongly associated with open habitats and categorized as Vulnerable on the Brazilian Red List of threatened species. These savannah enclaves with confirmed populations of pampas deer lie outside the species’ previously presumed historical range and are at least 350 km from any known extant population. Together, these savannah enclaves add c. 4,000 km2 to the pampas deer's currently known range. The small pampas deer populations in these enclaves are probably isolated by a matrix of Amazon forest, raising questions about spatial genetic structure and meta-population dynamics, and making them vulnerable to local extinction. We highlight the need for further studies, particularly genetic, to assess the conservation status of these populations, the results of which could potentially inform management decisions in other areas of the heavily fragmented range of this species.

Demographic characterization and social patterns of the Neotropical pampas deer

The most endangered subspecies of pampas deer Ozotoceros bezoarticus uruguayensis is an endemic cervidae of the Uruguayan temperate grasslands. The aim of our study was to assess the demographic trends, grouping structure and dynamic of this small and isolated population. We surveyed the population during seven years and detected an average of 117 (+ 72.7 SD) individuals (44 censuses). The average population structure observed was 55% adult females, 34% adult males, 10% juveniles, and 1% fawns, with a low recruitment rate of 0.11. The pampas deer is a gregarious cervidae with 62% of individuals being observed within groups of at least three animals. Nevertheless we observed substantial differences on group size and composition based on sex, reproductive status, season and trophic resources availability. The population dynamics showed significant changes around the year in the sexual aggregation-segregation pattern, corresponding with reproductive and physiological status. The mean density on this population (11 deer/ km2) is the highest reported for the species. Comparable data, from other populations, showed a significant correlation between density and sex ratio, with a reduction in the proportion of males with higher deer densities. An action plan for this endangered population should include initiatives involving private landowners, and guidelines to improve the deer habitat.

Molecular detection and identification of hemoparasites in pampas deer (Ozotoceros bezoarticus Linnaeus, 1758) from the Pantanal Brazil

Hemoparasites were surveyed in 60 free-living pampas deer Ozotoceros bezoarticus from the central area of the Pantanal, known as Nhecolândia, State of Mato Grosso do Sul, Brazil, through the analysis of nested PCR assays and nucleotide sequencing. Blood samples were tested for Babesia/Theileria, Anaplasma spp., and Trypanosoma spp. using nPCR assays and sequencing of the 18S rRNA, msp4, ITS, and cathepsin L genes. The identity of each sequence was confirmed by comparison with sequences from GenBank using BLAST software. Forty-six (77%) pampas deer were positive for at least one hemoparasite, according to PCR assays. Co-infection occurred in 13 (22%) animals. Based on the sequencing results, 29 (48%) tested positive for A. marginale. Babesia/Theileria were detected in 23 (38%) samples, and according to the sequencing results 52% (12/23) of the samples were similar to T. cervi, 13% (3/23) were similar to Babesia bovis, and 9% (2/23) were similar to B. bigemina. No samples were amplified with the primers for T. vivax, while 11 (18%) were amplified with the ITS primers for T. evansi. The results showed pampas deer to be co-infected with several hemoparasites, including species that may cause serious disease in cattle. Pampas deer is an endangered species in Brazil, and the consequences of these infections to their health are poorly understood.

First record of the invasive alien species Axis axis (Erxleben, 1777) (Artiodactyla: Cervidae) in Brazil

The exotic alien species Axis axis was introduced in the Americas at the beginning of last century and since then has established itself, expanding its distribution. This is the first record of this species in Brazil. In the extreme south of the country, an individual of A. axis was recorded with a camera trap in the Espinilho State Park. The area is close to the border of Uruguay and Argentina, countries where the species is established and from where this individual presumably originated. The Pampas biome is strongly disturbed by human activity in Brazil and since many native mammal species such as the Pampas deer Ozotoceros bezoarticus are threatened regionally. It is alarming that exotic populations can potentially rapidly expand their ranges in the region, as A. axis deer has done in Uruguay and Argentina. Possible consequences for this invasion are discussed.

Registro recente, redução de distribuição e atuais ameaças ao veado-campeiro Ozotoceros bezoarticus (Mammalia, Cervidae) no Estado de Santa Catarina, Brasil

Os campos naturais localizados na microrregião de Lages são o hábitat natural do veado-campeiro, e a localidade de Coxilha Rica, conhecida por seus campos limpos, o seu maior refúgio no Estado de Santa Catarina. Registros recentes e inéditos de veado-campeiro neste Estado são aqui publicados pela primeira vez, bem como evidências de redução de sua distribuição histórica nesta região. Em um ambiente campestre crescentemente invadido por plantios de espécies exóticas, parcelamento da terra, e queima dos campos, o manejo adequado dos locais onde o veado-campeiro ainda persiste pode ser decisivo para a continuidade de suas populações remanescentes.

Effect of cattle breeding on habitat use of Pampas deer Ozotoceros bezoarticus celer in semiarid grasslands of San Luis, Argentina

The largest population of the Argentinean Pampas deer Ozotoceros bezoarticus celer is found in the semiarid grasslands of the San Luis province. Despite relatively high deer numbers in the region, there has been concern that expansion of farming practices could displace the species. Since the 1990’s, cattle breeding has intensified especially as a result of the replacement of natural grassland with South African digit grass ( Digitaria eriantha) and African lovegrass ( Eragrostis curvula). In this study, we studied how deer in “El Centenario” ranch used available habitat types, especially to assess whether it preferentially used natural over exotic pastures. We employed 8 fixed line transects to record deer numbers and habitat use during the dry season, early rainy and late rainy seasons. We estimated a mean population size of 731 ± 121 individuals, a density of 1.95 ± 0.25 deer/km 2. Our results also showed that deer did not appear to select natural pastures over exotic ones, though D. eriantha grasslands with cattle were used less during the late rainy season. Grazed pastures with D. eriantha without cattle were used significantly more during all time periods. Our results therefore suggest that Pampas deer are not shifted by exotic pastures but we caution that it is important to manage these habitats sustainably (e.g. cattle load adjusted to grassland nutritional supply, rotational crops with parcel rest period), to ensure the conservation of the species within agricultural areas.

Reproduction in a semi-captive herd of pampas deer Ozotoceros bezoarticus

Information on reproductive traits of semi-captive breeding of the pampas deer Ozotoceros bezoarticus arerunguaensis, an endangered species, was registered during 20 years. Birth events were monitored every 1-2 days from 1981 to 2000, and birth date, mother and father identities, sex and mass of fawns were all registered. Although births occurred throughout the year, a seasonal pattern with a peak in spring was observed. Dispersion of births throughout the year increased in multiparous females that previously gave birth four times or more. The interval between two consecutive parturitions was ∼10 months, independently of the mother parity and of the sex of the fawn, but differed according to the timing of the previous birth. Individual variability in interbirth intervals was significantly higher in primiparous than in multiparous females. Hinds born in semi-captivity had their first birth earlier in their life than hinds that were originally captured (at <1 month of age) from the wild. Single fawns were observed in all but one birth, in which twins were observed. Sex ratio was not influenced by the female parity, the season, or by the father identity. Only the mother identity influenced offspring birth mass.

The food habits of Pampas deer Ozotoceros bezoarticus celer in relation to its conservation in a relict natural grassland in Argentina

The annual diet of a remnant population of the endangered Argentinian pampas deer Ozotoceros bezoarticus celer was determined by microhistological analysis of droppings. Three phases were distinguished, the exact timing and duration of which varied from year to year with climatic factors. From May to October, cool-season grasses were the characteristic food, especially Poa ligularis, with Sorghastrum pellitum, Schizachyrium plumigerum and Plantago patagonica. In spring and early summer, deer are large amounts of Sorghastrum seeds, together with P. ligularis foliage and the new-growth of warm-season Gramineae such as Cenchrus pauciflorus and S. plumigerum. From New Year until the onset of winter, major foods were the summer grasses S. pellitum, S. plumigerum, Bothriochloa springfieldii, Chloris retusa and the forb Conyza bonariensis. The deer were selective grazers, depending on fresh green material from a few plant species. The trophic overlap with other sympatric mammalian herbivores, both wild and domestic, suggests that competition for the trophic resource would intensify in dry years, and that food supply may be the limiting factor for pampas deer. Based on the dietary observations, measures are suggested to improve the grazing regime for the deer compatible with the existing working estancia. The creation of an ecosystem reserve for the little remaining natural Pampas grassland is urged.