Abstract:Species of Miconia are considered keystone plant resources for frugivorous birds in Neotropical forests, but for other ecosystems little of their ecological role is known. The fruiting phenology and the composition of frugivores of four Miconia species in savanna and palm swamp from the Brazilian Neotropical savanna were studied in three sites from November 2005 to May 2011. The hypothesis tested was that plants from different habitats share their frugivores and consequently promote links between habitats. Through focal plant observations (30–50 h per species in each site), 668 visits by 47 species of birds were recorded and plants from different habitats shared most of the frugivores (49–97%). The fruiting of Miconia chamissois in the palm swamp during the period of fruit scarcity (dry season) was accompanied by an enhancement in the frugivore bird richness and abundance in this habitat, providing indirect evidence of resource tracking. Bird species which primarily dwell in savanna recorded consuming fruits in palm swamps during the resource-scarce season is taken as evidence of landscape supplementation. Miconia assemblage studied here seems to promote a link between two adjacent habitats in the Neotropical savanna from Central Brazil, a link which is likely to be common in this naturally patchy ecosystem.

Ecological studies traditionally assume that generalist populations are homogeneous in the use of food resources, but empirical evidence supports that intraspecific differences in morphology, physiology and behaviour affect foraging decisions and promote diet variation among individuals. Furthermore, the temporal availability of resources may shape the dynamics of population trophic niche, which ultimately depends on individual niches. In this study, we investigated the seasonal changes in individual‐based networks between the Helmeted Manakin Antilophia galeata, a generalist frugivorous bird, and fruiting plants, following theoretical models of interindividual diet variation based on the Optimal Diet Theory. Selective individuals were the majority of the generalist population of the Helmeted Manakin. Our results suggest that the structure of the individual‐resource networks varied seasonally. We found that modularity was higher than expected by chance in the wet season, when fruit availability was also higher. In the dry season, modules disappeared and the network became more nested. These findings are consistent with the Distinct Preference Model of diet variation. We suggest that downscaling ecological networks to the individual level may reveal emergent properties that, albeit existent, are not evident in species–resources networks.

The objective of this study was to observe and compare the community of birds that utilize the tree species Faramea cyanea, in contiguous areas of cerradão and gallery forest, and also to characterize the behavioral patterns of the birds. The study was carried out in the Panga Ecological Station (Uberlândia, Minas Gerais State), in April and May 2001. Nine individuals of F. cyanea were observed in periods between 06:45-11:30 h for a total of 44.5 hours. There were 204 visits by 13 bird species. Tyrannidae was the most represented family (five species) and Turdidae, the most frequent (72.1% of visits). The number of consumed fruits was correlated with the permanence time on the plant. There was no significant difference between the two forests habitats, in terms of foraging tactics or fruit consumption strategies. In spite of the predominance of omnivorous birds (89.5%) in both habitats, the swallower strategy (84.2%) indicates high seed dispersal potential. Antilophia galeata, a frugivorous bird, presented the greatest rate of consumed fruits per minute in both gallery forest (2.15) and cerradão (1.06).

The relationship between plants and frugivorous animals is modulated by morphological and nutritional characteristics of fruits, as well as their seasonal availability across habitats. We evaluated fruiting phenology, fruit morphology and nutritional characteristics of 35 abundant plant species from 15 families associated with frugivorous birds from distinct habitats in the Cerrado (savanna, forest, and palm swamp). For a subset of 16 plant species, we also evaluated the overlap in interactions with frugivorous birds using data from the literature. Open-habitat plants had their fruiting peak during the rainy season, while fruiting of forest species was evenly distributed across the year. Plants of the same family exhibited similar fruit morphology and nutritional characteristics. Most plants had fruits with more sugars than lipids, while all species with higher lipid content were from savanna habitats and produced fruits during the rainy season, the peak reproductive season for birds. Assemblages of frugivorous birds exhibited considerable overlap, irrespective of habitat or fruiting season of plants. The complementarity found among habitats, considering seasonal availability and nutritional profile of fruits for frugivorous birds, is relevant for community maintenance and regeneration. Therefore, this landscape level complexity should always be considered in conservation and restoration policies for the Cerrado.

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