Analyzing weed community changes in extensive farming systemas of the pampas through a functional approach

p.121-130

Precipitation predictability during summer crop production in the Pampas Region of Argentina

p.9-20

Sulfur fertilization technology in the Argentine Pampas Region : a review

p.61-73

Analyzing weed community changes in extensive farming systemas of the pampas through a functional approach

p.121-130

Precipitation predictability during summer crop production in the Pampas Region of Argentina

p.9-20

Sulfur fertilization technology in the Argentine Pampas Region : a review

p.61-73

Phylogéographie et conservation de deux espèces de petits félidés des Andes : le chat des pampas et le chat des Andes

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

Effects of environmental conditions, human activity, reproduction, antler cycle and grouping on fecal glucocorticoids of free-ranging Pampas deer stags (Ozotoceros bezoarticus bezoarticus)

In this study, a commercial enzyme immunoassay (EIA) was validated in detecting glucocorticoids in Pampas deer feces, in order to investigate the influence of several factors on the adrenocortical function. Fecal samples, behavioral data and information concerning male grouping and antlers status were collected at a monthly basis during a 1 year period from free-ranging stags living at Emas National Park, Brazil (18 degrees S/52 degrees W). The results revealed that concentrations of fecal glucocorticoids in winter were significantly higher than those corresponding to spring and summer. In addition, dry season data presented higher levels than during the wet season. Significant difference was found between fecal levels of breeding stags in summer and nonbreeding stags, whereas no difference was observed between breeding stags in winter and nonbreeding stags. on the other hand, males from areas with frequent human disturbance exhibited higher glucocorticoid concentrations and flight distances than individuals from areas of lower human activity. Males with antlers in velvet had elevated levels compared with animals in hard antler or antler casting. Also, we found that glucocorticoid levels were higher in groups with three or more males than in groups with only one male. The flight distances showed positive correlation with fecal glucocorticoid. These data indicate that fecal glucocorticoid provides a useful approach in the evaluation of physiological effects of environment, inter-individuals relationship and human-induced stressors on free-ranging Pampas deer stags. (c) 2005 Elsevier B.V. All rights reserved.

Serosurvey for antibodies against Brucella abortus and Leptospira interrogans in pampas deer from Brazil

A survey for antibodies against Brucella abortus, and Leptospira interrogans was conducted on 17 pampas deer (Ozotocerus bezoarticus) from Pantanal Matogrossense (State of Mato Grosso do Sul, Brazil) and on 24 pampas deer from Parque Nacional de Emas (State of Goias, Brazil). Antibodies against B. abortus were detected by plate ag glutination, rose Bengal, and complement fixation tests, antibodies against Leptospira interrogans were detected by the microscopic agglutination test. All sera were negative for B. abortus antibodies and all deer sera from Parque Nacional de Emas were negative for L. interrogans antibodies. Four (24%) of 17 sera from Pantanal Matogrossense were positive for L. interrogans serovar (n = 2) hardjo, wolffi (n = 1) and mini (n = 1). While these diseases do not appear to be of major importance to the health status of Pampas deer, it appears that deer are reservoir for leptospirosis in one of the study areas.

Seasonal changes in fecal testosterone concentrations and their relationship to the reproductive behavior, antler cycle and grouping patterns in free-ranging male Pampas deer (Ozotoceros bezoarticus bezoarticus)

The purpose of this study was to validate noninvasive endocrine monitoring techniques for Pampas deer and to evaluate seasonal changes in testicular steroidogenic activity and their correlation to reproductive behavior, antler cycle and group size. Thus, fecal samples, behavioral data and observations of antler status were collected at monthly intervals during 1 year from free-ranging Pampas deer stags (three radio-collared individuals and 15 random individuals) living in Emas National Park, Brazil (18 degrees S latitude). Fecal steroids were extracted using 80% methanol and steroid concentrations were quantified by a commercial enzyme immunoassay (EIA). Fecal testosterone concentrations peaked in December-January (summer), March (early autumn) and in August-September (winter-spring), with minimal values from April-July. Reproductive behavior had two peaks, the first in December-January, characterized by predominately anogenital sniffing, flehmen, urine sniffing, chasing and mounting behavior, and the second peak in July-September (behavior primarily related to gland marking). There were significant correlations between fecal testosterone and reproductive behavior (r = 0.490), and between fecal testosterone and antler phases (r = 0.239). Antler casting and regrowth occurred under low testosterone concentrations, whereas velvet shedding was associated with high concentrations of testosterone. We inferred that Pampas deer stags exhibited a seasonal cycle that modulated sexual behavior and the antler cycle, and we concluded that fecal steroid analysis was a practical and reliable non-invasive method for the evaluation of the endocrine status of free-ranging Pampas deer. (c) 2004 Elsevier B.V. All rights reserved.

Environmental effect on the occurrence of anti-Neospora caninum antibodies in pampas-deer (Ozotoceros bezoarticus)

Sera obtained from pampas-deer (Ozotoceros bezoarticus) captured in two different Brazilian environments were analyzed for the presence of anti-Neospora caninum antibodies by the indirect fluorescent antibody test (IFAT). Samples were collected from 23 animals from a savanna area in the National Park of Emas, in the state of Goias, Brazil. This area is surrounded by cultivated lands and allows very little contact between wild and domestic animals. Another batch of samples was collected from 16 animals from the Pantanal region, in the state of Mato Grosso, Brazil. This area is a flood plain where domestic animals have intensive contact with cervids. The 39 samples were analyzed (IFAT >= 1:50), and the values for the occurrences found in the animals from each region were compared by the test for comparison of two proportions. of the 39 cervids examined, 38.46% (15) had anti-N. caninum antibodies. Three (13%) of the 23 samples from the National Park of Emas. and 12 (75%) of the 16 samples from the Pantanal were positive, with significant differences between regions (p < 0.001). These results suggested that the presence of domestic animals, mainly dogs and cattle, may be responsible for the greater occurrence of N. caninum in the Pantanal cervids.Thus, as a recommendation of the Conservation Units that care for the pampas-deer, attention should be taken to carefully monitor the flow of diseases between the domestic animals and this species. (c) 2005 Elsevier B.V. All rights reserved.

Genetic diversity of two Brazilian populations of the Pampas deer (Ozotoceros bezoarticus, Linnaeus 1758)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

CYTOGENETIC ANALYSIS OF THE PAMPAS DEER, OZOTOCEROS-BEZOARTICUS (MAMMALIA, CERVIDAE)

The chromosome constitution of five males and three females of the Pampas deer (Ozotoceros bezoarticus) coming mainly from the region of Corumba-MS, was studied. The diploid number of the species was reconfirmed as 68 chromosomes with Fundamental Number (FN) = 74. The X chromosome was the largest and the Y the smallest in the genome. Constitutive heterochromatin demonstrated by C banding was present in the centromeric region of all chromosomes, except in pair number two, which had none, and in chromosome X which had a stained region in the telomere on the long arm, Chromosomes pairs 3 and 4 bore Ag-NORs. The banding patterns differed from those of previous reports for this species. This may be due to subspecific differences.

Conservation genetics of the endangered Pampas deer (Ozotoceros bezoarticus)

The Pampas deer (Ozotoceros bezoarticus L. 1758) is the most endangered neotropical cervid, and in the past occupied a wide range of open habitats including grassland, pampas, savanna, and cerrado (Brazil) from 5 degrees to 41 degrees S. To better understand the effect of habitat fragmentation on gene flow and genetic variation, and to uncover genetic units for conservation, we examined DNA sequences from the mitochondrial control region of 54 individuals from six localities distributed throughout the present geographical range of the Pampas deer. Our results suggest that the control region of the Pampas deer is one of the most polymorphic of any mammal. This remarkably high variability probably reflects large historic population sizes of millions of individuals in contrast to numbers of fewer than 80 000 today. Gene flow between populations is generally close to one migrant per generation and, with the exception of two populations from Argentina, all populations are significantly differentiated. The degree of gene flow was correlated with geographical distance between populations, a result consistent with limited dispersal being the primary determinant of genetic differentiation between populations. The molecular genetic results provide a mandate for habitat restoration and reintroduction of Pampas deer so that levels of genetic variation can be preserved and historic patterns of abundance can be reconstructed. However, the source of individuals for reintroduction generally should be from populations geographically closest to those now in danger of extinction.

La población en situación de pobreza organizada en comedores populares de Pampas de San Juan; Lima-Perú 1989-1991

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