Walfrido Moraes Tomas

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) 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.

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.

Seasonality of the antler cycle of pampas deer (ozotoceros bezoarticus leucogaster) from the pantanal wetland, brazil

Antler cycle of tropical deer species is little known, in contrast to cervids of temperate zones. Since the antler cycle is controlled by the photoperiod and the consequent pattern of hormone secretion, temperate‐zone cervids show a seasonal antler cycle. For tropical deer, the seasonality is not well defined or is unknown for many species. This study reports monthly observations of the antler cycle over a four‐year period in pampas deer of the Pantanal wetland. There is a well defined antler cycle which appears to be regulated by photoperiod, despite the relatively low variation of photoperiod in this tropical region. The period of shortest daylength (June to August) corresponds to the highest frequency of velvet antlered males (91 % of males observed in that period). Only hard antlered males were observed in November, December, January and February. These results contrast with the seasonal antler cycle of Pampas deer population from Central Brazil, northern Argentina, Uruguay and Argentinian Pampas.

Real time polymerase chain reaction to diagnose Anaplasma marginale in cattle and deer (Ozotoceros bezoarticus leucogaster) of the Brazilian Pantanal.

Epizootiological study of Anaplasma marginale in regions that contain various reservoir hosts, co-existence of rickettsia pathogens, and common vectors is a complicated task. To achieve diagnosis of this rickettsia in cattle and campeiro deer of Brazilian Pantanal, a comparison was made between a real time polymerase chain reaction (RT-PCR) with intercalating Sybr Green fluorochrome and primers based on msp5 gene of A. marginale; a conventional PCR (C-PCR); and parasitological examination using thin blood smear stained with Giemsa-MayGrunwald. Both PCRs showed good performance in the diagnosis of A. marginale in cattle, and were superior to the parasitological exam. The RT-PCR detected seven positive campeiro deer (16.3%). This rate was significantly higher compared to C-PCR, which identified one animal as positive (2.3%), and also compared to parasitological diagnosis, which did not find any positive animals. The dissociation temperature average of positive reactions in cattle (81.72 °C ± 0.20) was identical to dissociation temperature found in the cervids (81.72 °C ± 0.12), suggesting that both animal species were infected with A. marginale. We concluded that RT-PCR can be used for A. marginale diagnosis and in epizootiological studies of cattle and cervids; in spite of the small number of campeiro deer samples, the results indicated that this wildlife species has importance in the Anaplasma epizootiology in the Brazilian Pantanal.

Density, occupancy, and activity pattern of two sympatric deer (Mazama) in the Atlantic Forest, Brazil

The red brocket (Mazama americana) and gray brocket deer (Mazama gouazoubira) are sympatric in the Atlantic Forest and present a number of ecological similarities in their diet and habitat use, although interspecific competition in these species is poorly understood. This study aimed to compare abundance and produce evidence of niche partitioning between these species. We estimated population density, activity patterns, habitat occupancy, and detection probabilities for the 2 species in a large remnant of the Atlantic Forest of Espírito Santo, Brazil. Abundance was estimated using the distance sampling technique, and occupancy, detectability, and activity patterns were assessed using camera-trap monitoring at 39 sample sites over a 1-year period. During surveys, we obtained 44 sightings of M. americana and 74 of M. gouazoubira, with 199 records in which the species was not discriminated. We applied a correction for the unidentified sightings to avoid underestimating density. The corrected population size estimates were 3,668 individuals (confidence interval [CI] 95%: 2,989–4,601) for M. americana and 6,701 (CI 95%: 5,857–7,667) for M. gouazoubira. Occupancy probability for M. americana was best described by the large trees density (diameter at breast height > 50 cm) and the edge forest distance, while M. gouazoubira did not present any habitat preferences based on the covariates used for modeling. M. americana was mostly nocturnal, whereas M. gouazoubira was active mainly during the day. We conclude that, despite the abundance of these sympatric species, and their occupation of the same habitats, they may avoid competing for habitat and feeding resources through differences in their activity patterns.

Survey of Leptospira spp in pampas deer (Ozotoceros bezoarticus) in the Pantanal wetlands of the state of Mato Grosso do Sul, Brazil by serology and polymerase chain reaction

This work reports a survey of Leptospira spp in pampas deer (Ozotoceros bezoarticus) in the Pantanal wetlands of the state of Mato Grosso do Sul, Brazil by serology and polymerase chain reaction (PCR). Seventy pampas deer were captured in the dry season and surveyed using PCR, microscopic agglutination test (MAT) (n = 51) and by both techniques (n = 47). PCR detected infections in two pampas deer and MAT detected infections in three. Through sequencing and phylogenetic analyses, the PCR-amplified fragment detected in deer was identified as Leptospira interrogans. Serovars Pomona and Butembo were detected using MAT and the highest titre was 200 for serovar Pomona. Epidemiological aspects of the findings are discussed.

How much can the number of jabiru stork (Ciconiidae) nests vary due to change of flood extension in a large Neotropical floodplain

The jabiru stork, Jabiru mycteria (Lichtenstein, 1819), a large, long-legged wading bird occurring in lowland wetlands from southern Mexico to northern Argentina, is considered endangered in a large portion of its distribution range. We conducted aerial surveys to estimate the number of jabiru active nests in the Brazilian Pantanal (140,000 km2) in September of 1991-1993, 1998, 2000-2002, and 2004. Corrected densities of active nests were regressed against the annual hydrologic index (AHI), an index of flood extension in the Pantanal based on the water level of the Paraguay River. Annual nest density was a non-linear function of the AHI, modeled by the equation 6.5 · 10-8 · AHI1.99 (corrected r2 = 0.72, n = 7). We applied this model to the AHI between 1900 and 2004. The results indicate that the number of jabiru nests may have varied from about 220 in 1971 to more than 23,000 in the nesting season of 1921, and the estimates for our study period (1991 to 2004) averaged about 12,400 nests. Our model indicates that the inter-annual variations in flooding extent can determine dramatic changes in the number of active jabiru nests. Since the jabiru stork responds negatively to drier conditions in the Pantanal, direct human-induced changes in the hydrological patterns, as well as the effects of global climate change, may strongly jeopardize the population in the region.

Leishmania (V.) braziliensis infecting bats from Pantanal wetland, Brazil: First records for Platyrrhinus lineatus and Artibeus planirostris

In the New World genus Leishmania parasites are etiological agents of neglected zoonoses known as leishmaniasis. Its epidemiology is very complex due to the participation of several species of sand fly vectors and mammalian hosts, and man is an accidental host. Control is very difficult because of the different epidemiological patterns of transmission observed. Studies about Leishmania spp. infection in bats are so scarce, which represents a large gap in knowledge about the role of these animals in the transmission cycle of these pathogens, especially when considering that Chiroptera is one of the most abundant and diverse orders among mammals. Leishmaniasis in Mato Grosso do Sul, Brazil are remarkably frequent, probably due to the abundance of its regional mastofauna. The recent record of L. braziliensis in bats from this state indicates the need to clarify the role of these mammals in the transmission cycle. In this study we evaluated the presence of Leishmania parasites in the skin of different species of bats, using PCR directed to Leishmania spp. kDNA for screening followed by PCR/RFLP analysis of the hsp70 gene for the identification of parasite species. Leishmania species identification was confirmed by PCR directed to the G6PD gene of L. braziliensis, followed by sequencing of the PCR product. Samples from 47 bats were processed, of which in three specimens (6.38%) was detected the presence of Leishmania sp. kDNA. PCR/RFLP and sequencing identified the species involved in the infection as L. braziliensis in all of them. This is the first report of Leishmania braziliensis in bats from Pantanal ecosystem and the first record of this species in Platyrrhinus lineatus and Artibeus planirostris, bats with a wide distribution in South America. These results reinforce the need to deepen the knowledge about the possibility of bats act as reservoirs of Leishmania spp. especially considering their ability of dispersion and occupation of anthropic environments.

Close relationship of Plasmodium sequences detected from South American pampas deer (Ozotoceros bezoarticus) to Plasmodium spp. in North American white-tailed deer

We report, for the first time, the presence of ungulate malaria parasites in South America. We conducted PCR-based surveys of blood samples of multiple deer species and water buffalo from Brazil and detected Plasmodium sequences from pampas deer (Ozotoceros bezoarticus) samples. Phylogenic analysis revealed that the obtained sequences are closely related to the Plasmodium odocoilei clade 2 sequence from North American white-tailed deer (Odocoileus virginianus). Nucleotide differences suggest that malaria parasites in South American pampas deer and North American P. odocoilei clade 2 branched more recently than the Great American Interchange.