Blastocerus Research Articles

Gastro‐Intestinal transit time in South American deer

AbstractThe study of diet and physiological peculiarities of the digestive system of neotropical deer is not well known and the literature shows inconsistencies. To better understand the digestive system of these mammals the difference in the gastro‐intestinal transit time of four species of neotropical deer (Mazama americana, Mazama gouazoubira, Mazama nana, Blastocerus dichotomus), kept in captivity, was evaluated. Four plants (Neonotonia wightii, Morus albans, Medicago sativa, Leucaena leucocephala) were utilized and two variables were measured, mean time of the beginning of the elimination (BE) and mean time of permanence (TP). The results obtained for BE indicated similarity among the deer species, with significant differences between M. gouazoubira (mean=13.62 hr) and M. Americana (mean=19.25 hr). For the plants, the BE was faster with N. wightii and L. leucocephala, and slower for M. sativa. The TP results for B. dichotomus showed longer time when compared to the other species, whereas M. gouazoubira had a lower permanence. Overall, N. wightii had the highest retention time in the digestive tract of all the deer species studied. Associated with this observation, N. wightii had the highest quantity of plant fiber of the plants tested. In a similar fashion M. sativa showed the lowest TP in the digestive tract of the deer and had the lowest quantity of acid detergent fiber. The data from this study showed that, within species, the shape of the excretion curve of the plants was similar when the animals consumed N. wightii or M. sativa. Blastocerus dichotomus and M. gouazoubira had the highest and the lowest gastro‐intestinal transit time, respectively. This suggests that these species characterize different abilities to digest high fiber food, and consequently, represent the two extremities in the morphophysiological adaptation within the deer species evaluated. This information is vital because it is important to know the digestive physiology to define the diet of captive animals, particularly regarding the quantity and quality of fiber. Zoo Biol 0:1–11, 2005. © 2005 Wiley‐Liss, Inc.

Aerial line transect survey to estimate abundance of marsh deer (Blastocerus dichotomus) (Illiger, 1815)

The objective was to estimate abundance of marsh deer in the Paraná River basin of this work. The results provided information to support further analysis of the impact of the Porto Primavera flooding lake over population. Sixty-nine animals were recorded by aerial survey using distance sampling methodology. Animals were widely distributed throughout the study area. The uncorrected data resulted in a estimate density of 0.0035 ind/ha and a population size of 636 individuals. Correcting the g for the animals that could be missed the calculated abundance was 896 (CV=0.27) individuals. This methodology was applied with success to survey marsh deer. The result was important to evaluate the marsh deer status in the area, and for future analysis of the impact of the flooding dam.

HEMATOLOGY OF FREE-LIVING MARSH DEER (BLASTOCERUS DICHOTOMUS) FROM SOUTHEAST BRAZIL

This work reports basic hematologic values of a sample of a population of free-living marsh deer (Blastocerus dichotomus) living by the Paraná River in Southeast Brazil. Hematologic values are presented separately for male, female, and young animals as well as for anesthetized and nonanesthetized cervids. Nonanesthetized deer restrained by physical means had significantly higher erythrocyte indices and total leukocyte counts. Comparisons of blood parameters of anesthetized animals of different ages and gender differed slightly, with only two significant differences observed: young animals had significantly higher red blood cell counts than adult males and a lower blood total protein content when compared to adult females. Results indicate that two main reference ranges for blood values should be considered for marsh deer, for blood obtained from anesthetized or physically restrained individuals.

Genetic Structure of Blastocerus dichotomus Populations in the Paraná River Basin (Brazil) Based on Protein Variability

The population structure of 147 marsh deer (Blastocerus dichotomus) from three areas in the Paraná River basin, Brazil, was studied by observing protein polymorphism at 17 loci. Six loci were polymorphic and 11 monomorphic. The proportion of polymorphic loci (P) was 35.29% and the average heterozygosity (H) was 6.31%. Wright's FST indicated that only 4.9% of the total variation in allelic frequencies was due to genetic differences between the three groups. The high value of F(IS) (0.246) indicated inbreeding in the marsh deer. Genetic distance values (D = 0.014-0.051) showed little divergence between the three areas. We suggest that probable mechanisms accounting for the genetic structure are female phylopatry and polygyny and also that inbreeding has resulted from decreasing areas of wetland leading to isolation, overhunting, and diseases transmitted by cattle.

Safeguarding the Pantanal Wetlands: Threats and Conservation Initiatives

Abstract: The Pantanal, one of the largest wetlands on the planet, comprises 140,000 km2 of lowland floodplain of the upper Rio Paraguai basin that drains the Cerrado of central Brazil. The diverse mosaics of habitats resulting from the varied soil types and inundation regimes are responsible for an extraordinarily rich terrestrial and aquatic biota, exemplified by the bird richest wetland in the world—463 birds have been recorded there—and the largest known populations of several threatened mammals, such as Pampas deer (Ozotoceros bezoarticus), marsh deer (Blastocerus dichotomus), giant otter (Pteronura brasiliensis), and jaguar (Panthera onca). Until recently, deforestation of the adjoining Brazilian central plateau was considered the major threat to this area, but now deforestation is a critical problem within the floodplain itself. More than 40% of the forest and savanna habitats have been altered for cattle ranching through the introduction of exotic grasses. And there are other threats that lead to large‐scale disruption of ecological processes, severely affecting biodiversity. Although the Pantanal wetland is a Biosphere Reserve and is considered a Wetland of International Importance, only 2.5% of the upper Paraguai River basin is formally protected. To date, protected areas have been created opportunistically and as such, although of undoubted value, protect only a fraction of the Pantanal's wildlife and habitats. Among the conservation initiatives in the area, the private sector is increasingly participating in the establishment of private reserves. The prospects are far from optimistic, however, and the major challenge is to find alternative socioeconomic models that allow for conservation and economic uses of the land in association with the development of specific environmental legislation that reflects the unique characteristics of the region.

Marsh deer (Blastocerus Dichotomus) reintroduction in the Jataí Ecological Station (Luís Antônio, SP): spatial preferences

Throughout the latter half of the twentieth century, wildlife habitat destruction and species extinctions have greatly increased. As the number of endangered species grows, the use of reintroduction as a conservation tool against species extinction increases. This study focuses on a 16-month study on marsh deer reintroduced in the Jataí Ecological Station. The animals were radio tagged and tracked daily between December 1998 and April 2000. Displacement activity and spatial preferences were monitored by triangulation. The animals wandered the floodplains inside the protected area and also a floodplain that is part of privately owned property on the western edge of the Jataí Ecological Station. During the study, most of the reintroduced marsh deer preferred the private floodplain area more than the floodplains inside the protected area. This preference revealed the ecological importance of the area and the necessity of its incorporation into the Jataí Ecological Station.

Retroflexão de bexiga: relato de caso em Blastocerus dichotomus (Cervo-do-Pantanal)

A bladder retroflexion was reported in Blastocerus dichotomus at The Veterinary Hospital of FCAV Jaboticabal-SP. A pregnat female from University breeder showed a retal and bladder prolapse. A cesarean were applied but not sucsseful for both. Then, the female was euthanized because the bladder had no conditions to be back again.

CAMPYLOBACTER SPP. EM FEZES DE CERVOS DO PANTANAL (BLASTOCERUS DICHOTOMUS)

ABSTRACT Campylobacter spp. was studied in feces samples from 74 marsh deer (Blastocerus dichotomus) from the western part of central Brazil, using direct growth in Butzler medium and filtration techniques. No strain species were isolated; these findings are discussed.

Tuberculosis survey of free-ranging marsh deer (Blastocerus dichotomus) in Brazil.

Esophageal-pharyngeal fluids from 53 free-ranging marsh deer (Blastocerus dichotomus) captured for a research program in the state of Mato Grosso do Sul, Brazil, were assayed for tuberculosis. Total DNA was extracted. amplified by polymerase chain reaction using specific primers for Mycobacterium tuberculosis complex (M. tuberculosis, M. bovis, M. microti, and M. africanum), and observed by agarose gel electrophoresis stained with ethidium bromide. All samples were negative. This, along with necropsy and histopathology data, suggests that these animals are not shedding and probably do not have active disease.

Ticks (Acari: Ixodidae) on wild marsh-deer (Blastocerus dichotomus) from Southeast Brazil: infestations before and after habitat loss.

The lake from Porto-Primavera hydroelectric power station inundated an area of 2,200 km2 at the border of São Paulo and Mato-Grosso do Sul States, Brazil. Infestations by ticks were evaluated on 135 marsh deer, Blastocerus dichotomus (Illiger), captured before and after inundation. Ticks were collected for identification, and infestation level of animals was assessed by scoring. Deer were divided into four groups according to capture location and temporal relation to the inundation. Groups 1, 2, and 3 were captured before inundation. Group 4 was captured after inundation. Four tick species were found: Amblyomma cajennense (F.), Amblyomma triste Koch, Anocentor nitens (Neumann), and Boophilus microplus (Canestrini). Groups 1, 2, 3, and 4 had 30, 45, 100, and 96%, respectively, of animals carrying B. microplus ticks. A. triste was observed on 16, 22, 22, and 88% of animals from groups 1, 2, 3, and 4, respectively. A. nitens and A. cajennense were observed only on group 4, on 32 and 16% of the animals, respectively. Groups 1 and 2 had only 4.8 and 6.1% of animals with high infestation levels, respectively, and no ticks on 46.8% and 45.5% of the animals, respectively. Conversely, groups 3 and 4 lacked noninfested animals and had high infestation levels on 77.8 and 50% of deer, respectively. Marsh area shrinkage was blamed for higher infestation levels on deer from groups 3 and 4. The widespread presence of A. triste on marsh deer, a Neotropical tick species, raises the possibility of a natural host-parasite relationship.

Latin American deer diversity and conservation: A review of status and distribution

We reviewed the scientific literature published from 1940 to 2002 on Latin American (Mexican and Central and South American) deer (Mammalia: Cervidae), focusing on conservation status and prediction of geographic distributions. The extant Latin American deer are the most diverse deer assemblage in the world (Cervinae: one genus, one species: Elk [Cervus elaphus]; Odocoilineae: six genera, 18 species: White-tailed deer [Odocoileus virginianus], mule deer [O. hemionus], marsh deer [Blastocerus dochotomus], pampas deer [Ozotoceros bezoarticus], huemul [Hippocamelus bisulcus], taruca [Hippocamelus antisensis], greater pudu [Pudu mephistophiles], lesser pudu [Pudu pudu], and six recognized species of brocket deer [Mazama americana, M. gouazoubira, M. nana, M. bricenni, M. chunyi, and M. rufina] as well as three recently proposed species [M. pandora, M. rondoni, and M. bororo]). Within this group, three genera (Odocoileus, Hippocamelus, and Blastocerus) have been well studied, whereas the genus Mazama, P. puda, P. mephistophiles, and H. antisensis have received little attention. The marsh deer, pampas deer, taruca, huemul, lesser pudu, and two Mazama species (Mazama nana and M. bororo) are the most endangered species. They are each listed as Convention International for the Trade of Endangered Species Appendix I and are considered by the International Union for Nature Conservation to be near threatened or endangered. We updated or created distribution maps for these species. Current research predominantly centres on easily available species (e.g., white-tailed deer in Mexico) or endangered species (e.g., marsh deer in Brazil). In contrast, the ecology and conservation status of the pudu, taruca, and Mazama sp. remain largely unknown.

RADIATIVE PROPERTIES OF THE SKIN AND HAIRCOAT OF CATTLE AND OTHER ANIMALS

Radiative properties (reflectance . , transmittance ., and absorptance .) were determined for wavelengths from 300 to 850 nm in the haircoat and the skin of water buffalo, deer (Pantanal deer, Blastocerus dichotomus), and cattle of the Holstein, Simmental, Canchim, Brangus, and Nelore breeds. The results showed that white hairs have higher . (0.60 to 0.67) than the other coat colors, but the gray coats (mixed white and dark hair) of the Nelore cattle presented higher . than that of the white coats of the European breeds at wavelengths lower than 600 nm. The light gray colored skin of the Canchim cattle had higher . (0.66) than the non–pigmented skin of Holstein (0.53). Red skins presented . values higher than those of dark gray and black skins. Buffalo skin (dark gray) presented an average . of 0.23 .0.02 and . of 0.77 .0.02. The red haircoat of the deer presented . lower (0.37) than that of cattle of the same color (0.58). However, there was little difference between deer and cattle with respect to reflectance and absorptance of the skin. As for the spectral transmittance of the skin, it was very low and about the same for both species, until 600 nm. In the range 600 to 850 nm, the . values for cattle rose to 0.17, while those for deer increased only to 0.12.

Composição e caracterização da fauna de mamíferos do Parque Nacional das Emas, Goiás, Brasil

Emas National Park is a very importam Conservation Unit in the Cerrado Biome. Nevertheless the fauna of this region is still poorly known. In this study, a revised list of the mammal fauna of the Emas National Park with comments about the composition and the number of species surveyed is presented. Eighty six species of mammals were recorded in the Park and neighboring area, including several rare and threatened species, like the bush dog (Speothos venaticus (Lund, 1842)), Marsh deer (Blastocerus dichotomus (Illiger, 1815)) and others. The giant rat (Kunsia tomentosus (Lichtenstein, 1830)) was recorded for the first time in a conservation unit. On the other hand, species usually very common in the Cerrado biome, don't occur in Emas National Park: the brazilian rabbit (Sylvilagus brasiliensis (Linnaeus, 1758)), marmosets (Callithrix spp.), and the punare (Thrichomys apereoides (Lund, 1841)).

Intramyocardial course of the coronary arteries in the marsh deer (Blastocerus dichotomus)

O trajeto das arterias coronarias foi estudado no cervo-do-pantanal para comparacao com os ruminantes domesticos. A arteria coronaria esquerda se origina na aorta, na superficie auricular cardiaca e divide-se em ramos paraconal e circunflexo, os quais preenchem o sulco paraconal interventricular e sulco subsinuoso, respectivamente; esta arteria tambem origina um ramo para o conus arteriosus imediatamente antes de entrar no miocardio. A arteria coronaria direita surge da aorta, na borda cranial cardiaca e termina nesta borda, proximo ao sulco subsinuoso interventricular, entretanto, sem preenche-lo.

Aspectos morfológicos do fígado do cervo-do-pantanal (Blastocerus dichotomus)

The macroscopic description of the liver of the Deer was performed for comparison with other ruminant species' liver, giving emphasis to the form, location, setting agents, disposition and lobation. AnimaIs from the Marsh Deer Project' held in Porto Primavera (Sao Paulo, Brazil) were used, after their deaths during the quarantine period. The morphology of the liver was given by visual analysis and further dissection. It was verified that the liver of the Deer is located in the cranial portion of the abdominal cavity in the right side, presenting a brow-reddish color and two surfaces, four borders, four lobes and five ligaments. The main characteristic that differs the liver of the Deer from the other ruminant livers is the absence of gallbladder.

Marsh Deer (Blastocerus dichotomus) Distribution as a Function of Floods in the Pantanal Wetland, Brazil

The marsh deer (Blastocerus dichotomus, Cervidae) inhabits floodplains and marshlands of South America and is threatened with extinction. We conducted two aerial surveys in the central southern region of the Pantanal to evaluate population distribution at the end of the dry season and the peak of the flooding season. Our results show an aggregated distribution during the dry season and a relatively diffused distribution in the flooding season. Population density estimates are 0.382 ± 0.362 deer/km2 in the dry season, and 0.395 ± 0.144 deer/km2 in the flooding season. Population size remained essentially unchanged between the seasons. In the study area, the marsh deer moved up to 20 km between the dry and flooding seasons. The design of protected areas should consider migration distances to offer enough area to protect marsh deer populations throughout the year.

Diet of the marsh deer (Blastocerus dichotomus) in the Pantanal wetland, Brazil

O cervo-do-pantanal (Blastocerus dichotomus, Cervidae) é uma espécie sul americana ameaçada de extinção. Existe pouca informação sobre a biologia desta espécie, incluindo dieta e requerimentos de habitat. O objetivo deste estudo foi determinar as espécies de plantas forrageadas pelo cervo no Pantanal, Brazil, onde se localiza a maior parte de sua população. A dieta do cervo-do-pantanal foi estudada através de microhistologia de restos vegetais em amostras de fezes. Um total de 41 espécies foram identificadas como componentes da dieta, 32 delas sendo consumidas durante a estação de cheias e 31 na estação seca. A maioria das espécies de plantas detectadas na dieta do cervo-do-pantanal é composta de plantas aqu ticas e/ou que apresentam tolerância a inundações sazonais ou solos encharcados. Blastocerus pode ser melhor definido como um estrategista "pastador-podador" porque grande parte de sua dieta é composta de brotos de várias espécies arbustivas e macrófitas de folha larga. The marsh deer (Blastocerus dichotomus, Cervidae) is a South American endangered species. There is little information on the biology of this species, including diet and habitat requirements. The objective of this study was to determine the plant species foraged by the marsh deer in the Pantanal wetland, Brazil, where most of its population is found. Marsh deer's diet was studied through microscopic analysis of fecal samples for remnants of plant species. A total of 41 species were identified as components of the diet, 32 of them found to be consumed during the flooding season and 31 in the dry season. Most plant species detected in the marsh deer's diet are aquatic and/or present tolerance to seasonal flooding and water-logged soils. Blastocerus could be best defined as a grazer-browser strategist because large part of its diet is composed of shoots of several species of shrub and broad-leaved aquatic macrophytes.

Cat flea (Ctenocephalides felis) infestation in quarantined marsh deer (Blastocerus dichotomus) populations.

Marsh deer (Blastocerus dichotomus) were captured for a research program in Brazil and maintained in quarantine stations. After 60 days, fleas were detected on animals and identified as Ctenocephalides felis felis. Elimination of the infestation was difficult. Animal treatment with a fipronil-based compound was effective, and subsequently captured animals were treated prophylactically. Some animals remained infested, and some died from the infestation.

Aerial surveys of caiman, marsh deer and pampas deer in the Pantanal Wetland of Brazil

The yacare caiman ( Caiman c. yacare) was illegally hunted in the Pantanal during the 1970s and 1980s at levels that may have reached one million skins per year. The possibility that yacare caiman had been over-exploited generated pressure for a monitoring programme for caiman populations. The marsh deer ( Blastocerus dichotomus) and pampas deer ( Ozotocerus bezoarticus) are listed as endangered in Brazil and need the protection of effective management programmes. Ground surveys are difficult for the extensive and inaccessible Pantanal Wetland, south-western Brazil, but aerial surveys provided information that allowed re-evaluation of conservation priorities. Caiman and marsh deer have larger populations than was believed. Preliminary data indicates that the pampas deer density decreased at a rate of about 30% per year from 1991 to 1993. This indicates the need for detailed ground-level studies for the pampas deer population in the Pantanal. We recommend a long term monitoring program using standardized counting procedures for wildlife populations in the Pantanal.

Marsh Deer (Blastocerus Dichotomus) ranging patterns in the Paraná River Valley, Brazil

Marsh Deer (Blastocerus Dichotomus) ranging patterns in the Paraná River Valley, Brazil