Composition and spatio-temporal dynamics of aquatic bird community in humid areas of Alto Parana Atlantic Forest

Abstract The northwestern portion of the Upper Paraná Atlantic Forest ecoregion is one of the most disturbed and fragmented areas in the Atlantic Forest, and little is known about the local avifauna. In this study, we have described the composition and diversity of the aquatic avifauna of this region and analyzed the patterns of similarity with respect to the seasonal as well as spatial distribution. We used the line transect sampling technique in six distinct humid areas (including lentic and lotic water bodies) during the dry and rainy seasons of 2012 and 2013. A total of 52 species of waterfowl were recorded. The species richness of the studied areas was surprisingly distinct; only seven waterfowl species, namely Cairina moschata (Linnaeus, 1758), Tigrisoma lineatum (Boddaert, 1783), Rosthramus sociabilis (Vieillot, 1817), Aramus guarauna (Linnaeus, 1766), Vanellus chilensis (Molina, 1782), Jacana jacana (Linnaeus, 1766), and Arundinicola leucocephala (Linnaeus, 1764), were common to these six studied areas. This indicated that the other bird species that were observed might be habitat selective. Moreover, the analysis of the composition of birds in the two seasons (dry and rainy) combined with their spatial distributions showed significant dissimilarities between the areas with lotic (river and constructed wetland) and lentic (lagoons) characteristics. Nevertheless, despite the small extent and low total richness of the entire study area, it was found to be home to 1/3 of all freshwater aquatic birds documented in the state of São Paulo, with the record of 5 migratory species and 11 new species added to the northwest of the state. The heterogeneity of local aquatic environments, habitat selection combined with seasonality, and the absence of other humid locations in the surroundings can explain the diversity and distribution of these birds in the water bodies of this uninvestigated Atlantic Forest ecoregion.

Resumo A porção noroeste da ecorregião Floresta Atlântica do Alto Paraná é uma das mais alteradas e fragmentadas da Mata Atlântica, da qual pouco se sabe sobre a avifauna local. Nosso objetivo foi descrever a diversidade e composição da avifauna aquática, bem como analisar os padrões de similaridade quanto a distribuição temporal e espacial destas aves nesta ecorregião. Utilizamos a transecção linear para amostragem em seis áreas úmidas (corpos dágua lênticos e lóticos), nos períodos de seca e chuva entre 2012 e 2013. Registramos 52 espécies de aves aquáticas e as riquezas das áreas mostraram-se distintas, pois apenas Cairina moschata (Linnaeus, 1758), Tigrisoma lineatum (Boddaert, 1783), Rosthramus sociabilis (Vieillot, 1817), Aramus guarauna (Linnaeus, 1766), Vanellus chilensis (Molina, 1782), Jacana jacana (Linnaeus, 1766), and Arundinicola leucocephala (Linnaeus, 1764) foram comuns às seis áreas, o que indica seleção de habitat. Quando analisada a composição das aves nos dois períodos aliada à distribuição espacial, encontramos dissimilaridades temporais acentuadas entre os ambientes com características lóticas (rio e aterro) e lênticas (lagoas). Isto mostra que, além das diferentes épocas sazonais, é necessário analisar separadamente os diferentes tipos de áreas úmidas. Por fim, apesar da extensão pequena e baixa riqueza total, a área amostrada abrigou 1/3 das aves aquáticas de água doce para o estado de São Paulo, cinco espécies migratórias e 11 novas espécies para o noroeste do estado. A heterogeneidade de ambientes aquáticos locais, forte seleção de habitat aliada à sazonalidade e ausência de outros locais úmidos em seu entorno, explicam a diversidade e distribuição destas aves estreitamente relacionadas aos corpos dágua desta desconhecida ecorregião da Mata Atlântica.

Syagrus flexuosa (Mart.) Becc. (Arecaceae) seedling recruitment at the edge and interior of Cerrado remnants

Abstract The edge effect has impacts on seed and seedling survival due to modifications in biotic and abiotic factors. Often, large-seeded tree species lost seed vectors in the forest edge due to the rarity or absence of large frugivores at this habitat type. In this study, I compared the seedling abundance and distribution of the palm Syagrus flexuosa between edges and interiors of three large Cerrado remnants. In every remnant, the number of seedlings around parent palms in the edge was smaller than around palm individuals located in the Cerrado interior. Moreover, the distribution of seedlings around parent palms differed between edges and interiors. In the edges, most seedlings were found under parent crowns, while in the interiors, the contrary occurred. The high concentration of seedlings under parent palms suggests a decrease of seed dispersal at the edges. Because S. flexuosa is a widely distributed palm that serves as an important resource for several animals along Cerrado habitats, changes on the regeneration process of this palm due to edge effects can further impact frugivore populations. Therefore, the decline of seedling establishment along forest edges implies changes in the Cerrado regeneration dynamics, which may compromise the persistence of ecological processes and animal communities.

Resumo O efeito de borda tem impactos severos na sobrevivência de sementes e plântulas devido a modificações dos fatores bióticos e abióticos. Frequentemente, espécies arbóreas com sementes grandes perdem seus dispersores na borda da floresta devido à raridade ou ausência de grandes frugívoros neste tipo de habitat. Neste estudo, comparei a abundância e distribuição de plântulas de S. flexuosa entre bordas e interiores de três grandes remanescentes de Cerrado. Em cada remanescente, o número de plântulas ao redor das palmeiras-mãe, na borda, era menor do que ao redor dos indivíduos no interior do Cerrado. Nas bordas, a maioria das plântulas foi encontrada junto às plantas mãe, enquanto no interior ocorreu o contrário. A alta concentração de plântulas sob as plantas adultas sugere diminuição da dispersão de sementes nas bordas. Como S. flexuosa é uma palmeira amplamente distribuída que serve como um recurso importante para vários animais nos habitats do Cerrado, mudanças no processo de regeneração dessa palmeira devido aos efeitos de borda podem impactar ainda mais as populações de frugívoros. Portanto, o declínio do estabelecimento de plântulas ao longo das bordas do Cerrado implica em mudanças na dinâmica de regeneração do Cerrado, o que pode comprometer a persistência de processos ecológicos e comunidades animais.

Composition and spatio-temporal dynamics of aquatic bird community in humid areas of Alto Parana Atlantic Forest / Composição e dinâmica espaço-temporal da comunidade de aves aquáticas em áreas úmidas da Floresta Atlântica do Alto Paraná

Abstract The northwestern portion of the Upper Paraná Atlantic Forest ecoregion is one of the most disturbed and fragmented areas in the Atlantic Forest, and little is known about the local avifauna. In this study, we have described the composition and diversity of the aquatic avifauna of this region and analyzed the patterns of similarity with respect to the seasonal as well as spatial distribution. We used the line transect sampling technique in six distinct humid areas (including lentic and lotic water bodies) during the dry and rainy seasons of 2012 and 2013. A total of 52 species of waterfowl were recorded. The species richness of the studied areas was surprisingly distinct; only seven waterfowl species, namely Cairina moschata (Linnaeus, 1758), Tigrisoma lineatum (Boddaert, 1783), Rosthramus sociabilis (Vieillot, 1817), Aramus guarauna (Linnaeus, 1766), Vanellus chilensis (Molina, 1782), Jacana jacana (Linnaeus, 1766), and Arundinicola leucocephala (Linnaeus, 1764), were common to these six studied areas. This indicated that the other bird species that were observed might be habitat selective. Moreover, the analysis of the composition of birds in the two seasons (dry and rainy) combined with their spatial distributions showed significant dissimilarities between the areas with lotic (river and constructed wetland) and lentic (lagoons) characteristics. Nevertheless, despite the small extent and low total richness of the entire study area, it was found to be home to 1/3 of all freshwater aquatic birds documented in the state of São Paulo, with the record of 5 migratory species and 11 new species added to the northwest of the state. The heterogeneity of local aquatic environments, habitat selection combined with seasonality, and the absence of other humid locations in the surroundings can explain the diversity and distribution of these birds in the water bodies of this uninvestigated Atlantic Forest ecoregion.

Resumo A porção noroeste da ecorregião Floresta Atlântica do Alto Paraná é uma das mais alteradas e fragmentadas da Mata Atlântica, da qual pouco se sabe sobre a avifauna local. Nosso objetivo foi descrever a diversidade e composição da avifauna aquática, bem como analisar os padrões de similaridade quanto a distribuição temporal e espacial destas aves nesta ecorregião. Utilizamos a transecção linear para amostragem em seis áreas úmidas (corpos d'água lênticos e lóticos), nos períodos de seca e chuva entre 2012 e 2013. Registramos 52 espécies de aves aquáticas e as riquezas das áreas mostraram-se distintas, pois apenas Cairina moschata (Linnaeus, 1758), Tigrisoma lineatum (Boddaert, 1783), Rosthramus sociabilis (Vieillot, 1817), Aramus guarauna (Linnaeus, 1766), Vanellus chilensis (Molina, 1782), Jacana jacana (Linnaeus, 1766), and Arundinicola leucocephala (Linnaeus, 1764) foram comuns às seis áreas, o que indica seleção de habitat. Quando analisada a composição das aves nos dois períodos aliada à distribuição espacial, encontramos dissimilaridades temporais acentuadas entre os ambientes com características lóticas (rio e aterro) e lênticas (lagoas). Isto mostra que, além das diferentes épocas sazonais, é necessário analisar separadamente os diferentes tipos de áreas úmidas. Por fim, apesar da extensão pequena e baixa riqueza total, a área amostrada abrigou 1/3 das aves aquáticas de água doce para o estado de São Paulo, cinco espécies migratórias e 11 novas espécies para o noroeste do estado. A heterogeneidade de ambientes aquáticos locais, forte seleção de habitat aliada à sazonalidade e ausência de outros locais úmidos em seu entorno, explicam a diversidade e distribuição destas aves estreitamente relacionadas aos corpos d'água desta desconhecida ecorregião da Mata Atlântica.

Syagrus flexuosa (Mart.) Becc. (Arecaceae) seedling recruitment at the edge and interior of Cerrado remnants / Recrutamento de plântulas em Syagrus flexuosa (Mart.) Becc. (Arecaceae), na borda e interior de remanescentes de Cerrado

The edge effect has impacts on seed and seedling survival due to modifications in biotic and abiotic factors. Often, large-seeded tree species lost seed vectors in the forest edge due to the rarity or absence of large frugivores at this habitat type. In this study, I compared the seedling abundance and distribution of the palm Syagrus flexuosa between edges and interiors of three large Cerrado remnants. In every remnant, the number of seedlings around parent palms in the edge was smaller than around palm individuals located in the Cerrado interior. Moreover, the distribution of seedlings around parent palms differed between edges and interiors. In the edges, most seedlings were found under parent crowns, while in the interiors, the contrary occurred. The high concentration of seedlings under parent palms suggests a decrease of seed dispersal at the edges. Because S. flexuosa is a widely distributed palm that serves as an important resource for several animals along Cerrado habitats, changes on the regeneration process of this palm due to edge effects can further impact frugivore populations. Therefore, the decline of seedling establishment along forest edges implies changes in the Cerrado regeneration dynamics, which may compromise the persistence of ecological processes and animal communities.

O efeito de borda tem impactos severos na sobrevivência de sementes e plântulas devido a modificações dos fatores bióticos e abióticos. Frequentemente, espécies arbóreas com sementes grandes perdem seus dispersores na borda da floresta devido à raridade ou ausência de grandes frugívoros neste tipo de habitat. Neste estudo, comparei a abundância e distribuição de plântulas de S. flexuosa entre bordas e interiores de três grandes remanescentes de Cerrado. Em cada remanescente, o número de plântulas ao redor das palmeiras-mãe, na borda, era menor do que ao redor dos indivíduos no interior do Cerrado. Nas bordas, a maioria das plântulas foi encontrada junto às plantas mãe, enquanto no interior ocorreu o contrário. A alta concentração de plântulas sob as plantas adultas sugere diminuição da dispersão de sementes nas bordas. Como S. flexuosa é uma palmeira amplamente distribuída que serve como um recurso importante para vários animais nos habitats do Cerrado, mudanças no processo de regeneração dessa palmeira devido aos efeitos de borda podem impactar ainda mais as populações de frugívoros. Portanto, o declínio do estabelecimento de plântulas ao longo das bordas do Cerrado implica em mudanças na dinâmica de regeneração do Cerrado, o que pode comprometer a persistência de processos ecológicos e comunidades animais.

Syagrus flexuosa (Mart.) Becc. (Arecaceae) seedling recruitment at the edge and interior of Cerrado remnants.

The edge effect has impacts on seed and seedling survival due to modifications in biotic and abiotic factors. Often, large-seeded tree species lost seed vectors in the forest edge due to the rarity or absence of large frugivores at this habitat type. In this study, I compared the seedling abundance and distribution of the palm Syagrus flexuosa between edges and interiors of three large Cerrado remnants. In every remnant, the number of seedlings around parent palms in the edge was smaller than around palm individuals located in the Cerrado interior. Moreover, the distribution of seedlings around parent palms differed between edges and interiors. In the edges, most seedlings were found under parent crowns, while in the interiors, the contrary occurred. The high concentration of seedlings under parent palms suggests a decrease of seed dispersal at the edges. Because S. flexuosa is a widely distributed palm that serves as an important resource for several animals along Cerrado habitats, changes on the regeneration process of this palm due to edge effects can further impact frugivore populations. Therefore, the decline of seedling establishment along forest edges implies changes in the Cerrado regeneration dynamics, which may compromise the persistence of ecological processes and animal communities.

Composition and spatio-temporal dynamics of aquatic bird community in humid areas of Alto Parana Atlantic Forest.

The northwestern portion of the Upper Paraná Atlantic Forest ecoregion is one of the most disturbed and fragmented areas in the Atlantic Forest, and little is known about the local avifauna. In this study, we have described the composition and diversity of the aquatic avifauna of this region and analyzed the patterns of similarity with respect to the seasonal as well as spatial distribution. We used the line transect sampling technique in six distinct humid areas (including lentic and lotic water bodies) during the dry and rainy seasons of 2012 and 2013. A total of 52 species of waterfowl were recorded. The species richness of the studied areas was surprisingly distinct; only seven waterfowl species, namely Cairina moschata (Linnaeus, 1758), Tigrisoma lineatum (Boddaert, 1783), Rosthramus sociabilis (Vieillot, 1817), Aramus guarauna (Linnaeus, 1766), Vanellus chilensis (Molina, 1782), Jacana jacana (Linnaeus, 1766), and Arundinicola leucocephala (Linnaeus, 1764), were common to these six studied areas. This indicated that the other bird species that were observed might be habitat selective. Moreover, the analysis of the composition of birds in the two seasons (dry and rainy) combined with their spatial distributions showed significant dissimilarities between the areas with lotic (river and constructed wetland) and lentic (lagoons) characteristics. Nevertheless, despite the small extent and low total richness of the entire study area, it was found to be home to 1/3 of all freshwater aquatic birds documented in the state of São Paulo, with the record of 5 migratory species and 11 new species added to the northwest of the state. The heterogeneity of local aquatic environments, habitat selection combined with seasonality, and the absence of other humid locations in the surroundings can explain the diversity and distribution of these birds in the water bodies of this uninvestigated Atlantic Forest ecoregion.

Density-dependent seed predation in Attalea geraensis Barb. Rodr. (Arecaceae) caused by bruchid beetles in the Brazilian Cerrado / Predação dependente da densidade em sementes de Attalea geraensis Barb. Rodr. (Arecaceae), causada por besouros no Cerrado brasileiro

Abstract Palms are an important component of Neotropical communities as they are often diverse and abundant. In some areas, palms occur in high density and act as limiting factor in tree recruitment by limiting tree seedling and sapling abundance. In this study, I evaluated the intensity of seed mortality caused by insects in Attalea geraensis, in a large area of preserved Cerrado (Serra do Cabral, MG, Brazil) during wet season when both A. geraensis fruits and bruchid beetles were abundant. I collected a total of 63 infructescences which had from 3 fruits and 7 seeds to 82 fruits and 251 seeds. Endocarps had from 1 to 6 seeds. Seed mortality per infructescence due to beetles (Pachymerus cardo) was intense, and increases positively and disproportionally according to seed number per infructescence. Besides that, average proportions of seeds preyed upon by insects were consistently high (> 0.83), irrespective of seed number per endocarp. Positive density-dependent seed mortality caused by specialized natural enemies has been assumed to promote species rarity, an important feature of species coexistence in Neotropical forests. Then, the intense seed mortality documented in this study suggests that seed predators may contribute to the richness and diversity of plant species in the Cerrado, the richest and most endangered savanna in the world.

Resumo Devido à abundância e diversidade, as palmeiras são um componente importante das comunidades neotropicais. Em algumas áreas as palmeiras ocorrem em elevada densidade, tornando-se um fator limitante ao recrutamento de árvores, por restringir a abundância de plântulas e árvores jovens. Neste estudo, avaliei a intensidade de mortalidade das sementes de Attalea geraensis , causada por insetos, em uma grande área preservada de Cerrado (Serra do Cabral, MG, Brasil), durante a estação chuvosa, quando frutos de A. geraensis e besouros predadores de sementes eram abundantes. Coletei um total de 63 infrutescências que tinham de 3 frutos e 7 sementes a 82 frutos e 251 sementes. Os endocarpos tinham de 1 a 6 sementes. Nas infrutescências a mortalidade das sementes causada por besouros (Pachymerus cardo) foi intensa e aumentou positiva e desproporcionalmente conforme o número de sementes por infrutescência. Além disso, independentemente do número de sementes por endocarpo, as proporções médias de sementes predadas por endocarpo foram consistentemente altas (> 0,83). A mortalidade densidade dependente positiva de sementes causada por inimigos naturais especializados é assumida como uma das principais causas da raridade das espécies vegetais, um fator importante para coexistência de espécies nas florestas neotropicais. Portanto, a intensa mortalidade de sementes documentada neste estudo sugere que predadores de sementes podem contribuir para a riqueza e diversidade de espécies de plantas no Cerrado, a savana mais rica e ameaçada do mundo.

Density-dependent seed predation in Attalea geraensis Barb. Rodr. (Arecaceae) caused by bruchid beetles in the Brazilian Cerrado.

Palms are an important component of Neotropical communities as they are often diverse and abundant. In some areas, palms occur in high density and act as limiting factor in tree recruitment by limiting tree seedling and sapling abundance. In this study, I evaluated the intensity of seed mortality caused by insects in Attalea geraensis, in a large area of preserved Cerrado (Serra do Cabral, MG, Brazil) during wet season when both A. geraensis fruits and bruchid beetles were abundant. I collected a total of 63 infructescences which had from 3 fruits and 7 seeds to 82 fruits and 251 seeds. Endocarps had from 1 to 6 seeds. Seed mortality per infructescence due to beetles (Pachymerus cardo) was intense, and increases positively and disproportionally according to seed number per infructescence. Besides that, average proportions of seeds preyed upon by insects were consistently high (> 0.83), irrespective of seed number per endocarp. Positive density-dependent seed mortality caused by specialized natural enemies has been assumed to promote species rarity, an important feature of species coexistence in Neotropical forests. Then, the intense seed mortality documented in this study suggests that seed predators may contribute to the richness and diversity of plant species in the Cerrado, the richest and most endangered savanna in the world.

The effect of size and density on nut removal in Syagrus loefgrenii Glassman (Arecaceae) in the Brazilian Cerrado / Efeito do tamanho e densidade sobre a remoção de sementes em Syagrus loefgrenii Glassman (Arecaceae) no Cerrado brasileiro

Abstract In this study I tested the effect of Syagrus loefgrenii nut size and number on the intensity of removal by rodents across seasons. Trials were performed in which piles of either small or large endocarps (1, 3, 6, 12, and 25) were subjected to removal by rodents in the Cerrado (Brazilian savanna). Despite of variations in the intensity of removal, always this process decrease conform endocarp number. Also, mean proportion of endocarp removal was unrelated to year period, initial number, and size of endocarps. Hence, endocarp removal was consistently negative density-dependent. As, in principle, the observed patterns of nut removal point out similar survival chances for both nut sizes, the pervasive negative density-dependent response emerges as a strategy in S. loefgrenii to swamp rodents all year round irrespective of seed size.

Resumo Avaliei o efeito do tamanho e densidade de endocarpos de Syagrus loefgrenii sobre a intensidade de remoção por roedores conforme a estação do ano. Para tanto, desenvolvi experimentos no Cerrado em que pilhas de endocarpos pequenos ou grandes (1, 3, 6, 12 e 25), foram sujeitos à remoção por roedores. Apesar da intensidade de remoção variar ao longo do ano, sempre esse processo teve relação inversa com o número de endocarpos. Além disso, em qualquer estação do ano, as proporções médias de endocarpos removidos sempre foram menores nas pilhas maiores, independentemente do tamanho dos endocarpos. Portanto, o processo de remoção de endocarpos foi negativamente dependente da densidade. Como, em princípio, os padrões de remoção em S. loefgrenii sugerem chances similares de sobrevivência tanto para endocarpos grandes, quanto pequenos, a preponderância de resposta negativamente dependente da densidade emerge como uma estratégia de S. loefgrenii voltada a saciar roedores em qualquer período do ano independentemente do tamanho de suas sementes.

The effect of size and density on nut removal in Syagrus loefgrenii Glassman (Arecaceae) in the Brazilian Cerrado.

In this study I tested the effect of Syagrus loefgrenii nut size and number on the intensity of removal by rodents across seasons. Trials were performed in which piles of either small or large endocarps (1, 3, 6, 12, and 25) were subjected to removal by rodents in the Cerrado (Brazilian savanna). Despite of variations in the intensity of removal, always this process decrease conform endocarp number. Also, mean proportion of endocarp removal was unrelated to year period, initial number, and size of endocarps. Hence, endocarp removal was consistently negative density-dependent. As, in principle, the observed patterns of nut removal point out similar survival chances for both nut sizes, the pervasive negative density-dependent response emerges as a strategy in S. loefgrenii to swamp rodents all year round irrespective of seed size.

Seed removal of Dipteryx alata Vog. (Leguminosae: Faboidae) in the edge and interior of Cerrado / Remoção de sementes de Dipteryx alata Vog. (Leguminosae: Faboidae) na borda e interior do Cerrado

Abstract Post-dispersal seed agents of mortality include pathogens, invertebrates, and vertebrates, which may shape tropical tree populations and communities. In this study I experimentally evaluated Dipteryx alata endocarp removal both in the interior and edge of Cerrado vegetation. Specifically, I simulated primary dispersion of endocarps by bats and evaluated secondary removal intensity according to habitat, season, and endocarp number. This study was developed in the Pombo Natural Municipal Park, a large Cerrado remnant with an area of 9,000 ha, located in the Western Brazil. In each of the two habitat types, I set down 45 points in which D. alata piles of 1, 3, 7, 15, and 40 endocarps were positioned. On average, endocarp removal in the interior was higher than in the edge, so that the intensity of removal varied from positive density-dependent (interior: rains), to negative density-dependent (edge: both seasons). Also, at both habitat types and seasons non removed endocarps were intensely attacked by fungus. Indeed, seed mortality by fungus infestation was positive density-dependent. The results indicate high propensity of endocarps to escape from removal in the edge, in principle, a defaunated area. As Dipteryx species strongly rely on caviomorph rodents for their dispersal, the scarcity of these vectors might reduce recruitment chances of D. alata in remnants of Cerrado. This imply in future changes in the vegetation structure from the edge to the interior towards low tree diversity.

Resumo A mortalidade pós-dispersão de sementes é causada por agentes como patógenos, invertebrados e vertebrados, os quais influenciam a dinâmica de populações e comunidades arbóreas. Nesse estudo, avaliei experimentalmente intensidade de remoção, por roedores, de endocarpos de Dipteryx alata na borda e interior da vegetação do Cerrado. Simulando a dispersão primária por morcegos, posicionei pilhas com diferentes números de endocarpos nos dois hábitats do cerrado e avaliei a remoção secundária, tanto na estação seca quanto na chuvosa. Os experimentos foram desenvolvidos no Parque Natural Municipal do Pombo, um grande remanescente com 9000 ha (Três Lagoas, MS, Brasil). Em cada um dos habitat defini 45 pontos nos quais pilhas com 1, 3, 7, 15 e 40 endocarpos foram posicionadas. A remoção de endocarpos foi significativamente maior no interior em relação à borda, tal que a intensidade de remoção variou de positivamente dependente da densidade (interior: chuvas), a negativamente dependente da densidade (borda: ambas as estações). Além disso, tanto na borda, quanto interior, bem como nas duas estações os endocarpos não removidos foram intensamente infestados por fungos. Consequentemente, a mortalidade causada por esses patógenos foi densidade dependente. Os resultados sugerem que os endocarpos de D. alata teriam maiores chances de escapar à remoção na borda, em princípio, depauperada em termos de roedores dispersores. A escassez desses vetores reduziria as chances de recrutamento de D. alata, favorecendo mudanças futuras na estrutura da vegetação, a partir da borda, em termos de menor diversidade arbórea.

Seed removal of Dipteryx alata Vog. (Leguminosae: Faboidae) in the edge and interior of Cerrado.

Post-dispersal seed agents of mortality include pathogens, invertebrates, and vertebrates, which may shape tropical tree populations and communities. In this study I experimentally evaluated Dipteryx alata endocarp removal both in the interior and edge of Cerrado vegetation. Specifically, I simulated primary dispersion of endocarps by bats and evaluated secondary removal intensity according to habitat, season, and endocarp number. This study was developed in the Pombo Natural Municipal Park, a large Cerrado remnant with an area of 9,000 ha, located in the Western Brazil. In each of the two habitat types, I set down 45 points in which D. alata piles of 1, 3, 7, 15, and 40 endocarps were positioned. On average, endocarp removal in the interior was higher than in the edge, so that the intensity of removal varied from positive density-dependent (interior: rains), to negative density-dependent (edge: both seasons). Also, at both habitat types and seasons non removed endocarps were intensely attacked by fungus. Indeed, seed mortality by fungus infestation was positive density-dependent. The results indicate high propensity of endocarps to escape from removal in the edge, in principle, a defaunated area. As Dipteryx species strongly rely on caviomorph rodents for their dispersal, the scarcity of these vectors might reduce recruitment chances of D. alata in remnants of Cerrado. This imply in future changes in the vegetation structure from the edge to the interior towards low tree diversity.

The effect of size and density on nut removal in Syagrus loefgrenii Glassman (Arecaceae) in the Brazilian Cerrado

Abstract In this study I tested the effect of Syagrus loefgrenii nut size and number on the intensity of removal by rodents across seasons. Trials were performed in which piles of either small or large endocarps (1, 3, 6, 12, and 25) were subjected to removal by rodents in the Cerrado (Brazilian savanna). Despite of variations in the intensity of removal, always this process decrease conform endocarp number. Also, mean proportion of endocarp removal was unrelated to year period, initial number, and size of endocarps. Hence, endocarp removal was consistently negative density-dependent. As, in principle, the observed patterns of nut removal point out similar survival chances for both nut sizes, the pervasive negative density-dependent response emerges as a strategy in S. loefgrenii to swamp rodents all year round irrespective of seed size.

Resumo Avaliei o efeito do tamanho e densidade de endocarpos de Syagrus loefgrenii sobre a intensidade de remoção por roedores conforme a estação do ano. Para tanto, desenvolvi experimentos no Cerrado em que pilhas de endocarpos pequenos ou grandes (1, 3, 6, 12 e 25), foram sujeitos à remoção por roedores. Apesar da intensidade de remoção variar ao longo do ano, sempre esse processo teve relação inversa com o número de endocarpos. Além disso, em qualquer estação do ano, as proporções médias de endocarpos removidos sempre foram menores nas pilhas maiores, independentemente do tamanho dos endocarpos. Portanto, o processo de remoção de endocarpos foi negativamente dependente da densidade. Como, em princípio, os padrões de remoção em S. loefgrenii sugerem chances similares de sobrevivência tanto para endocarpos grandes, quanto pequenos, a preponderância de resposta negativamente dependente da densidade emerge como uma estratégia de S. loefgrenii voltada a saciar roedores em qualquer período do ano independentemente do tamanho de suas sementes.

Density-dependent seed predation in Attalea geraensis Barb. Rodr. (Arecaceae) caused by bruchid beetles in the Brazilian Cerrado

Abstract Palms are an important component of Neotropical communities as they are often diverse and abundant. In some areas, palms occur in high density and act as limiting factor in tree recruitment by limiting tree seedling and sapling abundance. In this study, I evaluated the intensity of seed mortality caused by insects in Attalea geraensis, in a large area of preserved Cerrado (Serra do Cabral, MG, Brazil) during wet season when both A. geraensis fruits and bruchid beetles were abundant. I collected a total of 63 infructescences which had from 3 fruits and 7 seeds to 82 fruits and 251 seeds. Endocarps had from 1 to 6 seeds. Seed mortality per infructescence due to beetles (Pachymerus cardo) was intense, and increases positively and disproportionally according to seed number per infructescence. Besides that, average proportions of seeds preyed upon by insects were consistently high (> 0.83), irrespective of seed number per endocarp. Positive density-dependent seed mortality caused by specialized natural enemies has been assumed to promote species rarity, an important feature of species coexistence in Neotropical forests. Then, the intense seed mortality documented in this study suggests that seed predators may contribute to the richness and diversity of plant species in the Cerrado, the richest and most endangered savanna in the world.

Resumo Devido à abundância e diversidade, as palmeiras são um componente importante das comunidades neotropicais. Em algumas áreas as palmeiras ocorrem em elevada densidade, tornando-se um fator limitante ao recrutamento de árvores, por restringir a abundância de plântulas e árvores jovens. Neste estudo, avaliei a intensidade de mortalidade das sementes de Attalea geraensis , causada por insetos, em uma grande área preservada de Cerrado (Serra do Cabral, MG, Brasil), durante a estação chuvosa, quando frutos de A. geraensis e besouros predadores de sementes eram abundantes. Coletei um total de 63 infrutescências que tinham de 3 frutos e 7 sementes a 82 frutos e 251 sementes. Os endocarpos tinham de 1 a 6 sementes. Nas infrutescências a mortalidade das sementes causada por besouros (Pachymerus cardo) foi intensa e aumentou positiva e desproporcionalmente conforme o número de sementes por infrutescência. Além disso, independentemente do número de sementes por endocarpo, as proporções médias de sementes predadas por endocarpo foram consistentemente altas (> 0,83). A mortalidade densidade dependente positiva de sementes causada por inimigos naturais especializados é assumida como uma das principais causas da raridade das espécies vegetais, um fator importante para coexistência de espécies nas florestas neotropicais. Portanto, a intensa mortalidade de sementes documentada neste estudo sugere que predadores de sementes podem contribuir para a riqueza e diversidade de espécies de plantas no Cerrado, a savana mais rica e ameaçada do mundo.

Nut density and removal in Syagrus loefgrenii Glassman (Arecaceae) in the Brazilian Cerrado / Densidade de sementes e remoção em Syagrus loefgrenii Glassman (Arecaceae) no Cerrado brasileiro

Abstract In this study, I tested the effect of Syagrus loefgrenii nut number on the removal intensity by rodents across seasons. Also, I assessed both S. loefgrenii fruit production, and dispersion pattern to analyze the relationship between these parameters and nut removal. Trials were performed (autumn, winter, spring, and summer), in which endocarps were placed inside trays (5, 15, and 40 endocarps) in the Cerrado (Brazilian savanna). Syagrus loefgrenii exhibited clumped distribution, although its local density had no correlation with endocarp removal rate. Despite of variations, S. loefgrenii fruit production had no seasonal difference, although, high proportions of endocarps were year round removed. This mostly results from nearly complete endocarp loss in depots of 5 and 15, while the opposite occurred in those of 40. Hence, the intensity of removal consistently decreases with endocarp number, so that endocarp removal conformed to negative distance-dependence. As this palm exhibit clumped distribution and, in principle, fruit asynchronously, if, at least, a group of neighboring stems bore fruits simultaneously, an enhanced number of nuts might be available at a given site. Therefore, seeds within a dense S. loefgrenii fruit patch might experience high survival rates due to satiation of post dispersal seed predators.

Resumo Neste estudo, testei o efeito da densidade de endocarpos de Syagrus loefgrenii sobre a intensidade de remoção por roedores conforme a estação do ano. Também, avaliei tanto a produção de frutos, quanto o padrão de dispersão dessa palmeira em relação à intensidade de remoção de endocarpos. Executei experimentos no Cerrado (outono, inverno, primavera e verão), nos quais acondicionei 5, 15 e 40 endocarpos em pratos plásticos perfurados (pilhas experimentais). Syagrus loefgrenii exibiu distribuição agrupada. Apesar disso, a densidade local dessa palmeira em nenhuma estação esteve correlacionada com a taxa de remoção de endocarpos. Não ocorreram diferenças temporais significativas quanto aos níveis de frutificação, e, simultaneamente, documentei intensa remoção de endocarpos. Isso ocorreu, sobretudo, nas pilhas com 5 e 15 endocarpos, as quais, na maioria dos casos, perderam quase todos endocarpos. No entanto, as pilhas com 40 perderam poucos diásporos. Nesse sentido a intensidade de remoção decresceu consistentemente conforme o número de endocarpos, tal que esse processo mostrou ser negativamente dependente da distância. Syagrus loefgrenii exibiu padrão agrupado de distribuição, além de produzir frutos assincronicamente. Nesse sentido, caso um grupo de palmeiras vizinhas frutifique simultaneamente, uma grande quantidade de diásporos estará disponível em um dado local. Portanto, sementes em meio a uma densa carga de frutos podem ser favorecidas, uma vez que predadores pós-dispersão seriam saciados.

Nut density and removal in Syagrus loefgrenii Glassman (Arecaceae) in the Brazilian Cerrado.

In this study, I tested the effect of Syagrus loefgrenii nut number on the removal intensity by rodents across seasons. Also, I assessed both S. loefgrenii fruit production, and dispersion pattern to analyze the relationship between these parameters and nut removal. Trials were performed (autumn, winter, spring, and summer), in which endocarps were placed inside trays (5, 15, and 40 endocarps) in the Cerrado (Brazilian savanna). Syagrus loefgrenii exhibited clumped distribution, although its local density had no correlation with endocarp removal rate. Despite of variations, S. loefgrenii fruit production had no seasonal difference, although, high proportions of endocarps were year round removed. This mostly results from nearly complete endocarp loss in depots of 5 and 15, while the opposite occurred in those of 40. Hence, the intensity of removal consistently decreases with endocarp number, so that endocarp removal conformed to negative distance-dependence. As this palm exhibit clumped distribution and, in principle, fruit asynchronously, if, at least, a group of neighboring stems bore fruits simultaneously, an enhanced number of nuts might be available at a given site. Therefore, seeds within a dense S. loefgrenii fruit patch might experience high survival rates due to satiation of post dispersal seed predators.

Seed rain generated by bats under Cerrado's pasture remnant trees in a Neotropical savanna.

In this study we described the seed rain generated by bats under four Cerrado's tree species common within pastures, Buchenavia tomentosa, Couepia grandiflora, Licania humilis and Qualea grandiflora. We analyzed the similarity among the four tree species in terms of seed rain composition, and compared the number of seeds and seed species deposited under them. Besides that, we assessed the relationship between seed rain intensity and the density of each tree species. Then, we randomly selected 10 mature trees of each species to sample seed rain. We recorded a total of 4892 bat dispersed seeds from 11 species. Also, we observed that along the year seed deposition varied substantially under all trees. At least two seed sub-communities could be distinguished according to tree species used by bats as feeding roost. One related to Couepia grandiflora and Licania humilis, and the other to Buchenavia tomentosa and Qualea grandiflora trees. The variability of seed rain composition in any particular tree and the range of actual seed fall into a particular species indicate patchiness in seed rain, and the overall results appear to be consistent in terms of a substantial and diverse seed rain generated by bats in a highly anthropized landscape. This is the first study concerning seed dispersal by bats in modified Brazilian Cerrado, one of the most endangered biomes in the world. In this respect, by preserving a dense and diverse collection of remnant trees within today's pastures may, potentially, contribute to a faster Cerrado recovery in extensive areas that can be reclaimed for restoration in the future.

Seed rain generated by bats under Cerrados pasture remnant trees in a Neotropical savanna

Abstract In this study we described the seed rain generated by bats under four Cerrados tree species common within pastures, Buchenavia tomentosa, Couepia grandiflora, Licania humilis and Qualea grandiflora. We analyzed the similarity among the four tree species in terms of seed rain composition, and compared the number of seeds and seed species deposited under them. Besides that, we assessed the relationship between seed rain intensity and the density of each tree species. Then, we randomly selected 10 mature trees of each species to sample seed rain. We recorded a total of 4892 bat dispersed seeds from 11 species. Also, we observed that along the year seed deposition varied substantially under all trees. At least two seed sub-communities could be distinguished according to tree species used by bats as feeding roost. One related to Couepia grandiflora and Licania humilis, and the other to Buchenavia tomentosa and Qualea grandiflora trees. The variability of seed rain composition in any particular tree and the range of actual seed fall into a particular species indicate patchiness in seed rain, and the overall results appear to be consistent in terms of a substantial and diverse seed rain generated by bats in a highly anthropized landscape. This is the first study concerning seed dispersal by bats in modified Brazilian Cerrado, one of the most endangered biomes in the world. In this respect, by preserving a dense and diverse collection of remnant trees within today's pastures may, potentially, contribute to a faster Cerrado recovery in extensive areas that can be reclaimed for restoration in the future.

Resumo Neste estudo descrevemos a chuva de sementes gerada por morcegos sob quatro espécies arbóreas comuns em pastagens no Cerrado (Bouchenavia tomentosa, Couepia grandiflora, Licania humilis e Qualea grandiflora). Também, analisamos a similaridade quanto à composição da chuva de sementes depositada sob as quatro espécies arbóreas, além da relação entre a intensidade da chuva de sementes e densidade de cada espécies arbóreas. Para tanto, selecionamos aleatoriamente 10 árvores por espécie que fossem reprodutivamente maduras, para amostrar a chuva de sementes. Registramos um total de 4892 sementes, pertencentes a 11 espécies de plantas, dispersadas por morcegos. Durante o ano a deposição de sementes variou substancialmente sob todas as árvores amostradas. Duas sub-comunidades de sementes emergiram associadas às espécies arbóreas usadas por morcegos como abrigo de alimentação. Uma relacionada à Couepia grandiflora e Licania humilis, e outra relacionada à Buchenavia tomentosa e Qualea grandiflora. A variabilidade da composição da chuva de sementes sob qualquer uma das árvores, bem como a amplitude dessa chuva sob cada espécie de árvore indicou um padrão heterogêneo e intenso de deposição de uma coleção diversa de sementes em uma área altamente antropizada. Neste aspecto, a manutenção de uma rica e densa coleção de árvores remanescentes nas áreas de pastagens pode contribuir, potencialmente, para uma regeneração mais rápida do Cerrado em extensas áreas que podem requerer planos de restauração futuramente.

Seed rain generated by bats under Cerrado’s pasture remnant trees in a Neotropical savanna / Chuva de sementes gerada por morcegos sob árvores remanescentes do Cerrado no Brasil Central

Abstract In this study we described the seed rain generated by bats under four Cerrado’s tree species common within pastures, Buchenavia tomentosa, Couepia grandiflora, Licania humilis and Qualea grandiflora. We analyzed the similarity among the four tree species in terms of seed rain composition, and compared the number of seeds and seed species deposited under them. Besides that, we assessed the relationship between seed rain intensity and the density of each tree species. Then, we randomly selected 10 mature trees of each species to sample seed rain. We recorded a total of 4892 bat dispersed seeds from 11 species. Also, we observed that along the year seed deposition varied substantially under all trees. At least two seed sub-communities could be distinguished according to tree species used by bats as feeding roost. One related to Couepia grandiflora and Licania humilis, and the other to Buchenavia tomentosa and Qualea grandiflora trees. The variability of seed rain composition in any particular tree and the range of actual seed fall into a particular species indicate patchiness in seed rain, and the overall results appear to be consistent in terms of a substantial and diverse seed rain generated by bats in a highly anthropized landscape. This is the first study concerning seed dispersal by bats in modified Brazilian Cerrado, one of the most endangered biomes in the world. In this respect, by preserving a dense and diverse collection of remnant trees within today's pastures may, potentially, contribute to a faster Cerrado recovery in extensive areas that can be reclaimed for restoration in the future.

Resumo Neste estudo descrevemos a chuva de sementes gerada por morcegos sob quatro espécies arbóreas comuns em pastagens no Cerrado (Bouchenavia tomentosa, Couepia grandiflora, Licania humilis e Qualea grandiflora). Também, analisamos a similaridade quanto à composição da chuva de sementes depositada sob as quatro espécies arbóreas, além da relação entre a intensidade da chuva de sementes e densidade de cada espécies arbóreas. Para tanto, selecionamos aleatoriamente 10 árvores por espécie que fossem reprodutivamente maduras, para amostrar a chuva de sementes. Registramos um total de 4892 sementes, pertencentes a 11 espécies de plantas, dispersadas por morcegos. Durante o ano a deposição de sementes variou substancialmente sob todas as árvores amostradas. Duas sub-comunidades de sementes emergiram associadas às espécies arbóreas usadas por morcegos como abrigo de alimentação. Uma relacionada à Couepia grandiflora e Licania humilis, e outra relacionada à Buchenavia tomentosa e Qualea grandiflora. A variabilidade da composição da chuva de sementes sob qualquer uma das árvores, bem como a amplitude dessa chuva sob cada espécie de árvore indicou um padrão heterogêneo e intenso de deposição de uma coleção diversa de sementes em uma área altamente antropizada. Neste aspecto, a manutenção de uma rica e densa coleção de árvores remanescentes nas áreas de pastagens pode contribuir, potencialmente, para uma regeneração mais rápida do Cerrado em extensas áreas que podem requerer planos de restauração futuramente.

Chaco Chachalaca (Ortalis canicollis, Wagler, 1830) feeding ecology in a gallery forest in the South Pantanal (Brazil).

Cracids are generalist frugivores, which often exploit plant food resources such as flowers and leaves, mainly when fruit production declines. The Chaco chachalaca (Ortalis canicollis) is the most abundant cracid in the Pantanal (Brazil), and particularly common in the gallery forests. However, the factors related to their occurrence in this habitat type are unclear. In this study I describe the feeding habits and feeding niche breadth fluctuations of the Chaco chachalaca in relation to food resources abundance and diversity at the Miranda river gallery forest (Southern Pantanal). I also analyzed the relationships between Chaco chachalacas feeding activity and food resources abundance. This parameter (flowers and fruits) exhibited significant seasonal differences of abundance in which flowers were plentiful at the end of the dry, while fruits were abundant during the early wet season. However, food resources diversity to Chaco chachalacas exhibited no seasonal difference. Their feeding activity paralleled the availability of food resources, so that when some items were massively available an enhanced number of Chaco chachalacas foraged in the gallery forest, particularly during the prolonged dry season when they extensively used flowers and Genipa americana fruits. In fact, the Chaco chachalaca feeding niche breadth value presented low values in this period, while high values were common in the rest of the year. The flexible diet of this cracid, potentially favors their year round presence in the gallery forest, mainly during the prolonged dry season when the propensity for famine might be high. Since the Chaco chachalaca is among the largest and most abundant canopy frugivores in the gallery forest, it may contribute to forest regeneration, an underscored role due to the impact of annual floods and meandering dynamics on tree loss.