81 research outputs found
The use of sheepdogs in sheep production in southeastern Brazil
This study assessed the economic value of using sheepdogs as livestock guardians in southeastern Brazil by implementing a semi-structured interview format divided into four main categories: maintenance costs of sheep production, selling prices of carcasses, annual rate of depredation, and sheepdog acquisition and maintenance costs. According to our results, producers perceive the “unproductive” costs of sheepdogs similarly to the way they view taxes. However, management using sheepdogs as herd guardians tends to be most profitable for herds above 483 head from the fourth year on, being possibly more stable and predictable over time. In contrast, management without sheepdogs shows stochastic dynamics with occasional, though unpredictable, episodes of sheep depredation. This means that sheep farmers follow a cyclical decision strategy, which basically depends on the purchase price of the sheepdog
Parentage test in broad-snouted caimans (Caiman latirostris, Crocodylidae) using microsatellite DNA
In this study, microsatellite markers, developed for Alligator mississipiensis and Caiman latirostris, were used to assess parentage among individuals from the captive colony of Caiman latirostris at the University of São Paulo, in Piracicaba, São Paulo, Brazil. Many of the females in the colony were full siblings, which made maternal identification difficult due to genotypic similarity. Even so, the most likely mother could be identified unambiguously among offspring in most of the clutches studied. Two non-parental females displayed maternal behavior which would have misled managers in assigning maternity based on behavior alone. This set of variable loci demonstrates the utility of parentage testing in captive propagation programs
The relationship between nesting habitat and hatching success in Caiman latirostris (Crocodylia, Alligatoridae)
The Broad-snouted Caiman uses different habitats for nesting; it has temperature-dependent sex determination (TSD) and nesting habitat selection by females could affect sex and other hatchlings characteristics. Here we evaluated reproductive parameters in three nesting habitats: forest, savanna, and floating vegetation. We collected 154 caiman nests during the summer of 2001-2002. Since natural incubation could mask possible clutch-effects, eggs were collected soon after oviposition and artificially incubated. We found that eggs laid in the forest were wider than those laid in savanna, hatching success varied, decreasing from floating vegetation to forest. As egg width is positively correlated to female body size, the present results suggest that female body size could be related to nesting habitat use in Caiman latirostris. However, there were no differences in hatchling size among nesting habitats
Oral bacterial microbiota and traumatic injuries of free-ranging Phrynops geoffroanus (Testudines, Chelidae) in southeastern Brazil
During 2006 and 2007, we collected free-ranging Phrynops geoffroanus, from two anthropogenically altered rivers in southeastern Brazil. Oral microbiological samples were taken for isolation of aerobic and facultative anaerobic bacteria; a physical examination was performed;and we evaluated possible effects on the turtles’ health. Twenty-nine species of bacteria were isolated in Piracicaba River turtles (n=10), and twenty-four species in Piracicamirim stream turtles (n=8), most of them gram-negative. In both sites, potential pathogens for reptiles were: Escherichia coli, Klebsiella pneumoniae, Enterobacter agglomerans, Citrobacter freundii, and Bacillus sp. Although boatpropeller lesions were common on the carapace of the turtles, we have not found turtles with signs of clinical diseases. The oral bacterial microbiota of P. geoffroanus inhabiting the Piracicaba River basin are composed of a diverse microbe spectrum, and long-term studies of the effects of pollution and traumatic injuries on this population and its microbial flora are warranted
Thermoregulation in captive broad-snouted caiman (Caiman latirostris)
Background: Crocodilians are ectothermic animals. For this reason, the environmental temperature has substantial effects on their physiology and behavior. The thermoregulatory behavior of these animals involves the selective use of different types of environments. This behavior enables them to reach the temperature level for their metabolic activities. This study aimed to determine the influence of sex, body size, and reproductive stage on the body temperature (T b) of adult broad-snouted caiman (Caiman latirostris) in captivity. Thermal sensors were surgically implanted in the peritoneal cavity of 16 adult females and 4 adult males and programmed to register T b hourly during 6 months. Results: The diel T b pattern of the broad-snouted caiman reflected the variation among the microenvironmental temperatures used by the species (water surface, pool bottom, and ground). The sex of the animals had influence on their T b, but body size did not. Reproductive females had higher T b than non-reproductive females during October to early November. It is possible that this difference is a result of the ovulation period of the species. Sick animals appeared to show behavioral fever. Conclusions: The results of the present study suggest that several factors can affect the T b of adult broad-snouted caiman in captivity. Future studies should focus on the possible effect of thermoregulatory behavior on individuals' growth rate and reproductive performance.Fil: Bassetti, Luís A. B.. Universidade de Sao Paulo; BrasilFil: Marques, Thiago S.. Universidade de Sao Paulo; BrasilFil: Malvásio, Adriana. Universidade Federal do Tocantins; BrasilFil: Piña, Carlos Ignacio. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentina. Universidad Autónoma de Entre Ríos. Facultad de Ciencia y Tecnología; Argentina. Universidad Nacional de Entre Ríos. Facultad de Ciencias de la Alimentación; ArgentinaFil: Verdade, Luciano M.. Universidade de Sao Paulo; Brasi
Microbiota bacteriana oral e lesões traumáticas no cágado Phrynops geoffroanus (Testudines, Chelidae) no sudeste do Brasil
Entre 2006 e 2007, coletamos amostras microbiológicas da cavidade oral de cágados Phrynops geoffroanus de vida livre, em dois rios antropizados da região sudeste do Brasil, para o isolamento de bactérias aeróbicas e anaeróbicas facultativas, e realizamos um exame físico e avaliamos possíveis efeitos sobre o estado de saúde dos animais. Vinte e nove espécies de bactérias foram isoladas em cágados do rio Piracicaba (n=10), e vinte e quatro espécies em animais do ribeirão Piracicamirim (n=8), a maioria delas gram-negativas. Em ambos os sítios estudados foram isolados patógenos potenciais para répteis, como Escherichia coli, Klebsiella pneumoniae, Enterobacter agglomerans, Citrobacter freundii e Bacillus sp. Embora lesões na carapaça dos cágados, causadas por hélices de barcos, foram um achado comum no exame físico, não encontramos animais com sinais clínicos de doenças. A microbiota bacteriana oral dos cágados que habitam a bacia do rio Piracicaba é composta por um amplo espectro de bactérias, e estudos de longa duração sobre os efeitos da poluição e de lesões traumáticas nesta população e de sua microbiota oral são recomendados.During 2006 and 2007, we collected free-ranging Phrynops geoffroanus, from two anthropogenically altered rivers in southeastern Brazil. Oral microbiological samples were taken for isolation of aerobic and facultative anaerobic bacteria; a physical examination was performed; and we evaluated possible effects on the turtles' health. Twenty-nine species of bacteria were isolated in Piracicaba River turtles (n=10), and twenty-four species in Piracicamirim stream turtles (n=8), most of them gram-negative. In both sites, potential pathogens for reptiles were: Escherichia coli, Klebsiella pneumoniae, Enterobacter agglomerans, Citrobacter freundii, and Bacillus sp. Although boat propeller lesions were common on the carapace of the turtles, we have not found turtles with signs of clinical diseases. The oral bacterial microbiota of P. geoffroanus inhabiting the Piracicaba River basin are composed of a diverse microbe spectrum, and long-term studies of the effects of pollution and traumatic injuries on this population and its microbial flora are warranted
Notes on the hematology of free-living Phrynops geoffroanus (Testudines: Chelidae) in polluted rivers of Southeastern Brazil
Phrynops geoffroanus (Schweigger, 1812) is the freshwater turtle with the widest geographical distribution in South America. During 2006, physical examination and hematological evaluation were performed on free-ranging turtles from two polluted rivers, the Piracicaba River (n = 51) and its tributary Piracicamirim (n = 42), in southeastern Brazil. Red blood cell and thrombocyte counts, mean corpuscular volume and mean corpuscular hemoglobin levels differed in turtles from the two water courses. Although free-ranging turtles showed ectoparasites and boat propeler lesions, animals apparently had no signs of clinical disease. In spite of our results, further monitoring of the demography and health status of Phrynops geoffroanus in anthropogenically altered environments is recommended.FAPESP [05/00210-9]CNPqCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES
The influence of sugarcane pre‐harvest fire on hantavirus prevalence in Neotropical small mammals
The use of pre-harvest fire in sugarcane fields surprisingly results in an increase
in the abundance of Neotropical Sigmodontinae rodents, which might carry
hantavirus. By contrast, fire suspension induces a decline in rodents in the first
5 years. The present study aimed to evaluate the effect of sugarcane harvest
regimes on hantavirus prevalence in wild rodents. Field collections were carried
out on a sugarcane production area in Northeast S˜ao Paulo, which is responsible
for 30% of the ethanol production in Brazil. A few years after pre-harvest fire
suspension, a high prevalence of hantavirus was found in small rodents at lower
population density, but apparently higher population growth rate. Differences in
life cycle between the rodents and their predators may explain such density
patterns, as small rodents can breed twice or even three times each year, whereas
their predators usually breed only once a year. Similarly, the temporal dynamics
of the predator–prey relationship suggests that hantavirus prevalence is related to
small rodent’s population growth and not density. Only Akodon montensis,
Calomys tener, and Necromys lasiurus contained immunoglobulin G antibodiesagainst the recombinant nucleoprotein of Araraquara orthohantavirus, a genotype
of Andes orthohantavirus, with no interspecific variation in seroprevalence among
these species. However, males presented higher prevalence rate than females, possibly
due to a male-biased dispersal pattern and a higher frequency of antagonistic
interactions. Governance measures to mitigate the role of small wild rodents on
the emergence of hantavirus in agricultural landscapes dominated by sugarcane
plantations should include the use of wildlife-friendly management techniques
(e.g., to mitigate the mortality of the predators of small rodents), human capacity
building concerning wildlife-related conflicts, and multifunctionality of agricultural
landscapes. Future studies should prioritize the possible relationship between
microhabitat structure and hantavirus prevalence in small rodents in agricultural
landscapes dominated by sugarcane fields.info:eu-repo/semantics/publishedVersio
Cross-species microsatellite amplification in South American Caimans (Caiman spp and Paleosuchus palpebrosus)
Diagnóstico da pesquisa em biodiversidade no Brasil
Biodiversity is a result of millions of years of biological evolution, and is the component of the system which supports life on our planet. Besides the intrinsic value of each species, all of them as a whole, as well as of the interactions among the species, and their interaction with the physical and chemical environment, result in ecosystem services vital for supporting life on Earth. Because of that, the science of biodiversity is largely recognized as a priority area of scientific investigation both in developed and developing countries. In Brazil, the research on biodiversity can be divided in three parts: 1) discovery and characterization of biodiversity - including marine and human-altered landscapes - systematics and taxonomy; 2) understanding the functioning of ecosystems and environmental services, including in marine and human-altered landscapes; 3) bioprospecting of the chemical diversity of the Brazilian biota.A biodiversidade resulta de milhões de anos de evolução biológica e é o componente do sistema de suporte à vida de nosso planeta. Além do valor intrínseco de cada espécie, seu conjunto, bem como o de interações entre espécies e destas com o meio físico-químico, resultam em serviços ecossistêmicos imprescindíveis para manter a vida na Terra. Sendo assim, a ciência da biodiversidade é amplamente reconhecida como área prioritária de investigação científica, tanto nos países desenvolvidos como naqueles em desenvolvimento. No Brasil, a pesquisa em biodiversidade pode ser dividida em três principais vertentes: 1) descoberta e caracterização da biodiversidade, inclusive marinha e em paisagens alteradas - sistemática e taxonomia; 2) compreensão do funcionamento de ecossistemas e serviços ambientais, inclusive marinhos e em paisagens alteradas; 3) bioprospecção da quimiodiversidade da biota brasileira
- …