Cristiano Schetini de Azevedo

Influence of environmental enrichment on the behavior and physiology of mice infected by Trypanosoma cruzi

INTRODUCTION: Enriched environments normally increase behavioral repertoires and diminish the expression of abnormal behaviors and stress-related physiological problems in animals. Although it has been shown that experimental animals infected with microorganisms can modify their behaviors and physiology, few studies have evaluated how environmental enrichment affects these parameters. This study aimed to evaluate the effects of environmental enrichment on the behavior and physiology of confined mice infected with Trypanosoma cruzi. METHODS: The behaviors of 20 T. cruzi-infected mice and 20 non-infected mice were recorded during three treatments: baseline, enrichment, and post-enrichment. Behavioral data were collected using scan sampling with instantaneous recording of behavior every 30s, totaling 360h. Plasma TNF, CCL2, and IL-10 levels and parasitemia were also evaluated in infected enriched/non-enriched mice. Behavioral data were evaluated by Friedmans test and physiological data by one-way ANOVA and area under the curve (AUC) analysis. RESULTS: Results showed that environmental enrichment significantly increased exploratory behaviors and diminished inactivity. The use of environmental enrichment did not diminish circulating levels of TNF and IL-10 but diminished circulating levels of CCL2 and parasitemia. CONCLUSIONS: Positive behavioral and physiological effects of environmental enrichment were observed in mice living in enriched cages. Thus, environmental enrichment improved the welfare of these animals.

Microhabitat structure and food availability modelling a small mammal assemblage in restored riparian forest remnants

Abstract Small mammal populations respond to environmental changes in secondary riparian forest remnants in different ways, depending on the influences of biotic and abiotic variables. The present study evaluated how habitat/microhabitat structure and food availability influence small mammal assemblages in restored riparian forest remnants. Pitfall traps disposed in three linear transects were used to collect small mammals during 9 months of field work. General linear models were built to test the hypothesis that microhabitat structure (litter biomass and type – leaves and branches) and food availability (richness of zoochoric tree species and arthropods) influence species richness and abundance of small mammals. Three hundred and eighty-two individuals belonging to 14 species were captured. Biomass and type of litter (leaves or branches) provided greater structural to microhabitats, allowing the coexistence of morphologically similar species. Besides, food availability influenced foraging strategies of marsupials, forcing them to use the forest floor when zoochoric plants were rare. Thus, litter structure and food availability, allowing spatial segregation of the small mammal species using the forest fragments. We concluded that the maintenance of small mammals and their ecosystem services in restored riparian forests are dependent on habitat structure and food availability, thus, litter and zoochoric plants should be conserved in riparian forest fragments, especially those reforested.

Captive-born collared peccary (Pecari tajacu, Tayassuidae) fails to discriminate between predator and non-predator models

Captive animals may lose the ability to recognize their natural predators, making conservation programs more susceptible to failure if such animals are released into the wild. Collared peccaries are American tayassuids that are vulnerable to local extinction in certain areas, and conservation programs are being conducted. Captive-born peccaries are intended for release into the wild in Minas Gerais state, southeastern Brazil. In this study, we tested the ability of two groups of captive-born collared peccaries to recognize their predators and if they were habituated to humans. Recognition tests were performed using models of predators (canids and felids) and non-predators animals, as well as control objects, such as a plastic chair; a human was also presented to the peccaries, and tested as a separate stimulus. Anti-predator defensive responses such as fleeing and threatening displays were not observed in response to predator models. Predator detection behaviors both from visual and olfactory cues were displayed, although they were not specifically targeted at predator models. These results indicate that collared peccaries were unable to recognize model predators. Habituation effects, particularly on anti-predator behaviors, were observed both with a 1-h model presentation and across testing days. Behavioral responses to humans did not differ from those to other models. Thus, if these animals were to be released into the wild, they should undergo anti-predator training sessions to enhance their chances of survival.

Arachnidism, scorpionism and ophidism in Ouro Preto Municipality, Minas Gerais State, Brazil

INTRODUCTION This retrospective study shows the profile of arachnidism, ophidism, and scorpionism in the Ouro Preto Municipality, Brazil, from January 2007 to December 2013. METHODS The data were gathered from forms of the Epidemiological Surveillance Sector of the towns Healths Municipal Secretary. RESULTS Of the 412 envenomations, 308 were caused by spiders, 78 by scorpions, and 26 by snakes. The highest number of incidents involved people aged 20-34 years. Females were more affected than males. There were no reports of death. CONCLUSIONS The results show that envenomations caused by spiders, scorpions and snakes have decreased in recent years.

Riqueza e densidade de aves que nidificam em cavidades em plantações abandonadas de eucalipto

Monoculturas de arvores, como as de especies de eucalipto, tem substituido florestas naturais, impactando a fauna pela perda de habitat e recursos. Diversas especies de aves necessitam de ocos em arvores para nidificar. A falta de recursos como cavidades formadas pela degradacao da arvore ou locais apropriados para serem criadas cavidades leva a diminuicao na abundância das populacoes destas especies. Este trabalho tem o objetivo de comparar a riqueza e a densidade de aves que nidificam em ocos em areas de plantacao de eucalipto abandonadas com areas de vegetacao nativa em duas unidades de conservacao em Minas Gerais. Em cada tipo de vegetacao de cada reserva foram estabelecidos 25 pontos, nas quais foi utilizado o metodo de contagem por remocao para o levantamento das especies de aves. A riqueza de especies de aves de cada area foi estimada por Jackniffe e a densidade foi estimada atraves do metodo de maxima verossimilhanca; modelos candidatos que poderiam influenciar a abundância das aves foram avaliados utilizando-se o Criterio de Informacao Akaike (AIC). Os resultados mostraram que a riqueza de especies foi maior nas areas de florestas nativas e que a densidade foi significantemente mais alta nas areas de florestas nativas, e que o tipo de vegetacao e a hora do dia influenciam na abundância e deteccao das aves. Esses resultados indicam que as plantacoes de eucaliptos influenciam negativamente a comunidade de aves que nidificam em ocos, provavelmente por causa da falta de cavidades ou de sub-bosque. Plantacoes de eucaliptos normalmente nao substituem as florestas nativas e seu uso deve ser controlado em areas de conservacao.