Local extinction of an important seed disperser does not modify the spatial distribution of the endemic palm Astrocaryum aculeatissimum (Schott) Burret (Arecaceae)

Spatial pattern of the palm Astrocaryum aculeatissimum was investigated in an urban Atlantic Forest fragment (Tijuca National Park, Brazil) where its main seed disperser, the red-rumped agouti Dasyprocta leporina, is locally extinct. A 120 × 130 m plot (1.56 ha) was established in which all A. aculeatissimum individuals were quantified, georeferenced, and classified by ontogenetic stages, namely, seedling, infant, juvenile, immature individual, and adult. Analyses were performed using Ripley's K function. We recorded 376 individuals, most of which were in the juvenile stage (n = 228). The spatial pattern was aggregated as observed for other palm species. Seedlings and infants were not associated with adults, whereas juveniles and immature individuals were observed closer to adults than expected. The distance between each seedling and the nearest adult ranged from 3 to 30 m (mean ± sd = 11.8 ± 7.8), which is similar to the agouti dispersal distances reported in other studies. Despite the importance of agoutis for the seedling recruitment of A. aculeatissimum, their short-term absence does not affect the spatial distribution of this palm in the studied area

The exotic palm Roystonea oleracea (Jacq.) O. F. Cook (Arecaceae) on an island within the Atlantic Forest Biome: naturalization and influence on seedling recruitment

Here, we investigated the population structure of the exotic palm Roystonea oleracea in a swamp on an island within the Atlantic Forest Biome, evaluating its influence on the seedling recruitment of other plant species. The population structure was analyzed in six 4 × 30 m plots, within which we categorized all individuals by ontogenetic stage. The influence of R. oleracea on the seedling recruitment of other plant species was evaluated in 2 × 2 m plots established beneath palm crowns and in adjacent areas without palms. We recorded 53 R. oleracea individuals. The majority (56.6%) of the R. oleracea population was composed of immature adults, followed by mature adults. The density, richness and diversity of seedling species differed significantly between areas beneath and away from palms, the values being lower beneath R. oleracea crowns. Our results indicate that R. oleracea recruitment does not require human intervention, the number of reproductive individuals characterizing successful naturalization. This underscores the need for management policies aimed at palm eradication in order to avoid reductions in biodiversity

Dieta da paca (Cuniculus paca) usando métodos indiretos numa área de cultura agrícola na Floresta Atlântica brasileira

http://dx.doi.org/10.5007/2175-7925.2010v23n1p235A paca (Cuniculus paca) é um roedor que se alimenta de frutos de acordo com sua disponibilidade. Este estudo descreve o consumo de frutos por pacas numa área de cultivo sombreado de cacau na Floresta Atlântica do Espírito Santo. Foi realizada a procura de vestígios indiretos deixados por estes animais, como as marcas características dos incisivos, para reconhecer os frutos consumidos. Doze espécies foram consumidas pelas pacas, pertencentes a 10 famílias e 10 gêneros. Essa lista inclui seis espécies nativas e seis espécies exóticas. Alguns frutos foram consumidos inteiros, enquanto que outros tiveram seu exocarpo ou suas sementes descartadas. Os métodos indiretos mostraram-se adequados para caracterizar a dieta dessa espécie e podem complementar os métodos de pesquisa convencionais tais como visualização direta e análises de conteúdo estomacal ou fecal. A ocorrência das pacas na área de cultivo demonstra plasticidade quanto à sua dieta e a possibilidade de conservação de populações dessa espécie em áreas alteradas fora das unidades de conservação

Diet of paca (Cuniculus paca) using indirect methods in an agricultural area in the Brazilian Atlantic Forest

The paca (Cuniculus paca) is a rodent that feeds on fruits according to their availability. This study describes the consumption of fruit by paca in an area of shaded cultivation of cocoa in the Brazilian Atlantic Forest. The study was carried out by the search for tracks left by these animals, such as marks of incisors found in fruits, in order to recognize the fruits consumed. We recorded 12 species consumed by the pacas, belonging to 10 families and 10 genera. The list included six native species and six exotic species. Some fruits were eaten as a whole, while others had their exocarp or seeds discarded. The indirect methods showed suitability to characterize the diet of this species, and they could complement conventional research methods such as direct sighting and analyses of stomachal or fecal contents. The occurrence of pacas in the agricultural area shows the plasticity of their diet and the possibility of conserving populations of this species in disturbed areas outside nature reserves

Carrion consumption by Dasyprocta leporina (RODENTIA: DASYPROCTIDAE) and a review of meat use by agoutis

The consumption of the carrion of a tapiti by a reintroduced female Dasyprocta leporina was observed in the wild. Herein, besides describing this event, we reviewed other evidence of vertebrate consumption by agoutis. Most of the studies describing this behaviour have been carried out in captivity. The preyed animals included birds and small rodents, which were sometimes killed by agoutis. This pattern suggests that this is not an anomalous behaviour for the genus, reflecting its omnivorous habits. This behaviour can be a physiologically sound feeding strategy, so new studies should focus on the temporal variation in the consumption of this resource, possibly related to food scarcity periods or to reproductive seasons, when the need for high-quality food tends to increase