Densidade populacional, uso do espaço e dieta do roedor Kerodon rupestris (Mammalia: Caviidae) em uma área do alto sertão sergipano, Nordeste do Brasil

• Autor(a) principal: Conceição, Anderson Mendonça
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFS
• Texto Completo: http://ri.ufs.br/jspui/handle/riufs/16352
• topic: Roedores; Sergipe; Animais da caatinga; Dieta; Densidade demográfica; Alimentação; Caatinga; Densidade; Estratificação vertical; Precipitação; Density; Vertical stratification; Food; Precipitation; CIENCIAS BIOLOGICAS::ECOLOGIA

Kerodon rupestris (rock cavy) is an herbivorous rodent specialized in rocky environments, with endemic occurrence in semiarid areas of Brazil. The objective of this studywastocharacterize the population density, use of space and diet in a 120 ha of rocky outcrops inthearea of caatinga in Sergipe. The density was estimated by distance sampling in four lineartransections (between 292-817m), alternated in the morning and afternoon. The use of thespace was verified at the moment of the detection of the rock cavy in the soil, rockorvegetation and its variation was tested by GLM. The records of rodent activity in the useofspace for air temperature classes and the use of height classes in vegetation were evaluatedbyGLM. The diet was observed ad libitum in the area of transections, the niche amplitudewas calculated and the influence of precipitation on the composition of the diet was assessedby simple logistic regression. Were carried out 612 observations of K. rupestris in 23,172m, and the best fitted model was Half-normal/Cosine for an estimate of 12.45 individuals/ha. There was a difference in the use of strata (p=0.021), with 71% of the records in the rock. Theactivity of this rodent was recorded between temperatures of 23 and 45 °C, withgreateractivity between 31-34 °C, and been influenced by this variable (p=2.743 -8). The rockcavydiffered in relation to the use of height classes in vegetation (p=0.021), with greater useof theground (55%) and records of use of 10 plant species. For the diet, this rodent consumedsixcategories (leaf, fallen leaf, flower, fallen flower, bark and stem), with leaf-basedfeeding(56.5%), reflecting a low niche range (Ba=0.321). For the consumption of categoriesbyspecies, this rodent was also a specialist (Ba=0.209), with greater use of leaves of Bauhiniacheilantha (25.26%) and fallen flowers of Cenostigma pyramidale (22%). The lowrainfall inthe region influenced the consumption of leafs (p=1.85 -5) and of the species B. cheilantha(p=0.044), while the high precipitation influenced the consumption of fallen flowers (p=2.82-5)and C. pyramidale (p=1.34 -5). The high population density of K. rupestris in the localityconfirms the importance of protected areas for the conservation of this species. The studiedpopulation presents similar characteristics of the rodent species that occur in islands, beingthat the rock cavy to cluster in the mesic refuges formed by the rocky outcrops. The rockcavyconsumes the vegetation associated with these environments, with a diet composed mainlyoffreshly fallen leaves and flowers, which are influenced by precipitation. The greaterconsumption of these food items can be favored by the level of water found in their tissues, which is important for survival in a semiarid environment with irregular rainfall, as well ascarbohydrates found in the nectar of flowers.