About rats and jackfruit trees: modeling the carrying capacity of a Brazilian Atlantic Forest spiny-rat Trinomys dimidiatus (Günther, 1877) – Rodentia, Echimyidae – population with varying jackfruit tree (Artocarpus heterophyllus L.) abundances

We carried out a six-year study aimed at evaluating if and how a Brazilian Atlantic Forest small mammal community responded to the presence of the invasive exotic species Artocarpus heterophyllus, the jackfruit tree. In the surroundings of Vila Dois Rios, Ilha Grande, RJ, 18 grids were established, 10 where the jackfruit tree was present and eight were it was absent. Previous results indicated that the composition and abundance of this small mammal community were altered by the presence and density of A. heterophyllus. One observed effect was the increased population size of the spiny-rat Trinomys dimidiatus within the grids where the jackfruit trees were present. Therefore we decided to create a mathematical model for this species, based on the Verhulst-Pearl logistic equation. Our objectives were i) to calculate the carrying capacity K based on real data of the involved species and the environment; ii) propose and evaluate a mathematical model to estimate the population size of T. dimidiatus based on the monthly seed production of jackfruit tree, Artocarpus heterophyllus and iii) determinate the minimum jackfruit tree seed production to maintain at least two T. dimidiatus individuals in one study grid. Our results indicated that the predicted values by the model for the carrying capacity K were significantly correlated with real data. The best fit was found considering 20~35% energy transfer efficiency between trophic levels. Within the scope of assumed premises, our model showed itself to be an adequate simulator for Trinomys dimidiatus populations where the invasive jackfruit tree is present.

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A Small Mammal Community in a Forest Fragment, Vegetation Corridor and Coffee Matrix System in the Brazilian Atlantic Forest

PLoS ONE ◽

10.1371/journal.pone.0023312 ◽

2011 ◽

Vol 6 (8) ◽

pp. e23312 ◽

Cited By ~ 15

Author(s):

Mariana Ferreira Rocha ◽

Marcelo Passamani ◽

Júlio Louzada

Keyword(s):

Atlantic Forest ◽

Small Mammal ◽

Brazilian Atlantic Forest ◽

Matrix System ◽

Forest Fragment ◽

Small Mammal Community ◽

Mammal Community

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Distribution, population size and conservation of the endemic muriquis (Brachyteles spp.) of the Brazilian Atlantic Forest

Oryx ◽

10.1017/s003060530700230x ◽

2009 ◽

Vol 43 (02) ◽

pp. 254 ◽

Cited By ~ 12

Author(s):

Andre A. Cunha ◽

Carlos Eduardo Viveiros Grelle ◽

Jean Philippe Boubli

Keyword(s):

Population Size ◽

Atlantic Forest ◽

Brazilian Atlantic Forest

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New distribution reports of Rhagomys rufescens (Rodentia: Sigmodontinae) Thomas, 1886

Check List ◽

10.15560/8.3.557 ◽

2012 ◽

Vol 8 (3) ◽

pp. 557

Author(s):

Caryne Aparecida de Carvalho Braga ◽

Maria Rita Silvério Pires

Keyword(s):

Atlantic Forest ◽

Small Mammal ◽

Rainy Season ◽

First Record ◽

Mountain Range ◽

Brazilian Atlantic Forest ◽

Pitfall Traps ◽

Juvenile Male ◽

New Distribution ◽

Forest Biome

Rhagomys rufescens is a rare, arboreal sigmodontine rodent endemic to the Brazilian Atlantic Forest biome. This species is known from eight localities in Brazil. Here we present a new report based on four individuals of this species registered in Serra do Ouro Branco, municipality of Ouro Branco (Minas Gerais, Brazil). One juvenile male, one adult male and two juvenile females were captured in pitfall traps during the rainy season, in a study of small mammal ecology. This is the first record for the Espinhaço Mountain range and the northernmost report for the species in this state, 85 km northeast of the last registered location.

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Small mammal populations of an agroecosystem in the Atlantic Forest domain, southeastern Brazil

Brazilian Journal of Biology ◽

10.1590/s1519-69842007000100025 ◽

2007 ◽

Vol 67 (1) ◽

pp. 179-186 ◽

Cited By ~ 18

Author(s):

PS. D’Andrea ◽

R. Gentile ◽

LS. Maroja ◽

FA. Fernandes ◽

R. Coura ◽

...

Keyword(s):

Population Dynamics ◽

Species Richness ◽

Atlantic Forest ◽

Small Mammal ◽

Abundant Species ◽

Common Species ◽

Southeastern Brazil ◽

Small Mammal Community ◽

Population Sizes ◽

Didelphis Aurita

This study reports 2 years of the population dynamics and reproduction of a small mammal community using the removal method. The study was conducted in a rural area of the Atlantic Forest, in Sumidouro, Rio de Janeiro State, Brazil. The population sizes, age structure and reproduction were studied for the four most common species in the study area. The overall diversity was 1.67 and ranged between 0.8 to 1.67. The species richness was 13 considering the whole study. The most abundant species were the rodents Nectomys squamipes (n = 133), Akodon cursor (n = 74), Oligoryzomys nigripes (n = 25) and the marsupials Didelphis aurita (n = 58) and Philander frenatus (n = 50). Seven other rodents were captured once: Necromys lasiurus, Akodon montensis, Sooretamys angouya, Oecomys catherine, Oxymycterus judex, Euryzygomatomys spinosus and Trinomys iheringi. There were higher peaks for diversity and species richness during the winter (dry) months, probably due to higher food availability. The marsupials had a seasonal reproduction with highest population sizes at the end of the rainy seasons. Nectomys squamipes reproduced mostly during rainy periods. Akodon cursor reproduced predominantly in the winter with the highest population peaks occurring during this season. The analysis of the population dynamics of the rodent species indicated that no species behaved as an agricultural pest, probably due to the heterogeneous landscape of high rotativity of vegetable cultivation. Rodent populations were more susceptible to the removal procedure than marsupial ones.

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