Frugivore Diversity Research Articles

Long-term biotic homogenization in the East African Rift System over the last 6 million years of hominin evolution.

Eastern Africa preserves the most complete record of human evolution anywhere in the world but we have little knowledge of how long-term biogeographic dynamics in the region influenced hominin diversity and distributions. Here, we use spatial beta diversity analyses of mammal fossil records from the East African Rift System to reveal long-term biotic homogenization (increasing compositional similarity of faunas) over the last 6 Myr. Late Miocene and Pliocene faunas (~6-3 million years ago (Ma)) were largely composed of endemic species, with the shift towards biotic homogenization after ~3 Ma being driven by the loss of endemic species across functional groups and a growing number of shared grazing species. This major biogeographic transition closely tracks the regional expansion of grass-dominated ecosystems. Although grazers exhibit low beta diversity in open environments of the Early Pleistocene, the high beta diversity of Mio-Pliocene browsers and frugivores occurred in the context of extensive woody vegetation. We identify other key aspects of the Late Cenozoic biogeographic development of eastern Africa, their likely drivers and place the hominin fossil record in this context. Because hominins were undoubtedly influenced by many of the same factors as other eastern African mammals, this provides a new perspective on the links between environmental and human evolutionary histories.

Genomic signatures of past megafrugivore‐mediated dispersal in Malagasy palms

Abstract Seed dispersal affects gene flow and hence genetic differentiation of plant populations. During the Late Quaternary, most fruit‐eating and seed‐dispersing megafauna went extinct, but whether these animals have left signatures in the population genetics of their food plants, particularly those with large, ‘megafaunal’ fruits (i.e. >4 cm—megafruits), remains unclear. Here, we assessed the population history, genetic differentiation and recent migration among populations of four animal‐dispersed palm (Arecaceae) species with large (Borassus madagascariensis), medium‐sized (Hyphaene coriacea, Bismarckia nobilis) and small (Chrysalidocarpus madagascariensis) fruits on Madagascar. We integrated double‐digest restriction‐site‐associated DNA sequencing (ddRAD) of 167 individuals from 25 populations with (past) distribution ranges for extinct (e.g., giant lemurs and elephant birds) and extant seed‐dispersing animals, landscape and human impact data, and applied linear mixed‐effects models to explore the drivers of genetic variation in Malagasy palms. Palm populations that shared more megafrugivore species in the past had lower genetic differentiation than populations that shared fewer megafrugivore species. This suggests that megafrugivore‐mediated seed dispersal in the past may have led to frequent gene flow among populations. In comparison, extant frugivore diversity only decreased genetic differentiation in the small‐fruited palm. Furthermore, genetic differentiation of all palm species decreased with landscape connectivity (i.e. environmental suitability, forest cover and river density) and human impact (i.e. road density), while migration rates of the small‐fruit palm increased with road density. Synthesis. Our results suggest that the legacy of megafrugivores regularly achieving long dispersal distances is still reflected in the population genetics of palms that were formerly dispersed by such animals. Furthermore, low genetic differentiation was possibly maintained after the megafauna extinctions through alternative dispersal (e.g. human‐ or river‐mediated), long generation times and long lifespans of these megafruit palms. Our study illustrates how species interactions that happened >1000 years ago can leave imprints in their population genetics.

Drivers of intraspecific variation in seed dispersal can differ across two species of fleshy‐fruited savanna plants

AbstractVarious factors may mediate the visitation of frugivores to fruiting plants, which can dictate the quantum of seeds removed (dispersed) away from the parent plant. Past studies have laid emphasis on species‐specific factors and environmental contexts that frugivores may use as cues to make foraging decisions and differentially visit various plant species. However, differences in plant traits (intrinsic factors) and local environmental contexts (extrinsic factors) can influence the diversity and abundance of frugivores that visit individual plants of the same species, resulting in intraspecific variation in seed dispersal. We observed individuals of two co‐fruiting plant species with morphologically similar fruits—Naringi crenulata and Ziziphus oenopolia—for 134 h and examined the influence of fruit crop size, plant height, and fruiting neighborhood on the diversity of visiting avian frugivores and quantum of fruit removal for individual plants. We found that despite their similarity in fruits and sharing of a similar set of frugivore species, the two plant species differed in how they attracted frugivores, with consequences for fruit removal rates. Fruit crop size was an important determinant of fruit removal for N. crenulata¸ while plant height led to greater visitation and fruit removal for Z. oenopolia. We discuss potential reasons for the difference in frugivore visitation and fruit removal for the two plant species. Our results support a growing body of evidence that intraspecific variation in seed dispersal is pervasive and highly context‐dependent, and describe frugivore interactions of two plant species from an understudied tropical savanna.

Effects of Habitat and Fruit Scent on the Interactions between Short-tailed Fruit Bats and Piper Plants.

Piper is a mega-diverse genus of pioneer plants that contributes to the maintenance and regeneration of tropical forests. In the Neotropics, Carollia bats use olfaction to forage for Piper fruit and are a main disperser of Piper seeds via consumption and subsequent defecation during flight. In return, Piper fruits provide essential nutrients for Carollia year-round. There is evidence that the types and diversity of Piper frugivores are influenced by the primary habitat type of different Piper species (forest and gap), with forest Piper depending more on bats for seed dispersal; however, this pattern has not been tested broadly. We aimed to characterize and compare the interactions between Carollia and Piper across forested and gap habitats, and further investigate whether differences in fruit traits relevant to bat foraging (i.e., scent) could underlie differences in Carollia-Piper interactions. We collected nightly acoustic ultrasonic recordings and 24 h camera trap data in La Selva, Costa Rica across 12 species of Piper (six forest, six gap) and integrated this information with data on Carollia diet and Piper fruit scent. Merging biomonitoring modalities allowed us to characterize ecological interactions in a hierarchical manner: from general activity and presence of bats, to visitations and inspections of plants, to acquisition and consumption of fruits. We found significant differences in Carollia-Piper interactions between forested and gap habitats; however, the type of biomonitoring modality (camera trap, acoustics, diet) influenced our ability to detect these differences. Forest Piper were exclusively visited by bats, whereas gap Piper had a more diverse suite of frugivores; the annual diet of Carollia, however, is dominated by gap Piper since these plants produce fruit year-round. We found evidence that fruit scent composition significantly differs between forest and gap Piper, which highlights the possibility that bats could be using chemical cues to differentially forage for gap vs. forest Piper. By integrating studies of Piper fruit scent, plant visitation patterns, and Carollia diet composition, we paint a clearer picture of the ecological interactions between Piper and Carollia, and plant-animal mutualisms more generally.

Patterns of variation in fleshy diaspore size and abundance from Late Triassic-Oligocene.

Vertebrate-mediated seed dispersal is a common attribute of many living plants, and variation in the size and abundance of fleshy diaspores is influenced by regional climate and by the nature of vertebrate seed dispersers among present-day floras. However, potential drivers of large-scale variation in the abundance and size distributions of fleshy diaspores through geological time, and the importance of geographic variation, are incompletely known. This knowledge gap is important because fleshy diaspores are a key mechanism of energy transfer from photosynthesis to animals and may in part explain the diversification of major groups within birds and mammals. Various hypotheses have been proposed to explain variation in the abundance and size distribution of fleshy diaspores through time, including plant-frugivore co-evolution, angiosperm diversification, and changes in vegetational structure and climate. We present a new data set of more than 800 georeferenced fossil diaspore occurrences spanning the Triassic-Oligocene, across low to mid- to high palaeolatitudes. We use this to quantify patterns of long-term change in fleshy diaspores, examining the timing and geographical context of important shifts as a test of the potential evolutionary and climatic explanations. We find that the fleshy fruit sizes of angiosperms increased for much of the Cretaceous, during the early diversification of angiosperms from herbaceous ancestors with small fruits. Nevertheless, this did not cause a substantial net change in the fleshy diaspore size distributions across seed plants, because gymnosperms had achieved a similar size distribution by at least the Late Triassic. Furthermore, gymnosperm-dominated Mesozoic ecosystems were mostly open, and harboured low proportions of specialised frugivores until the latest Cretaceous, suggesting that changes in vegetation structure and plant-frugivore co-evolution were probably not important drivers of fleshy diaspore size distributions over long timescales. Instead, fleshy diaspore size distributions may be largely constrained by physical or life-history limits that are shared among groups and diversify as a plant group expands into different growth forms/sizes, habitats, and climate regimes. Mesozoic gymnosperm floras had a low abundance of fleshy diaspores (<50% fleshy diaspore taxa), that was surpassed by some low-latitude angiosperm floras in the Cretaceous. Eocene angiosperm floras show a mid- to high latitude peak in fleshy fruit abundance, with very high proportions of fleshy fruits that even exceed those seen at low latitudes both in the Eocene and today. Mid- to high latitude proportions of fleshy fruits declined substantially over the Eocene-Oligocene transition, resulting in a shift to more modern-like geographic distributions with the highest proportion of fleshy fruits occurring in low-latitude tropical assemblages. This shift was coincident with global cooling and the onset of Southern Hemisphere glaciation, suggesting that rapid cooling at mid- and high latitudes caused a decrease in availability of the climate conditions most favourable for fleshy fruits in angiosperms. Future research could be focused on examining the environmental niches of modern fleshy fruits, and the potential effects of climate change on fleshy fruit and frugivore diversity.

Frugivore-mediated seed dispersal in fragmented landscapes: Compositional and functional turnover from forest to matrix.

Seed dispersal by frugivores is a fundamental function for plant community dynamics in fragmented landscapes, where forest remnants are typically embedded in a matrix of anthropogenic habitats. Frugivores can mediate both connectivity among forest remnants and plant colonization of the matrix. However, it remains poorly understood how frugivore communities change from forest to matrix due to the loss or replacement of species with traits that are less advantageous in open habitats and whether such changes ultimately influence the composition and traits of dispersed plants via species interactions. Here, we close this gap by using a unique dataset of seed-dispersal networks that were sampled in forest patches and adjacent matrix habitats of seven fragmented landscapes across Europe. We found a similar diversity of frugivores, plants, and interactions contributing to seed dispersal in forest and matrix, but a high turnover (replacement) in all these components. The turnover of dispersed seeds was smaller than that of frugivore communities because different frugivore species provided complementary seed dispersal in forest and matrix. Importantly, the turnover involved functional changes toward larger and more mobile frugivores in the matrix, which dispersed taller, larger-seeded plants with later fruiting periods. Our study provides a trait-based understanding of frugivore-mediated seed dispersal through fragmented landscapes, uncovering nonrandom shifts that can have cascading consequences for the composition of regenerating plant communities. Our findings also highlight the importance of forest remnants and frugivore faunas for ecosystem resilience, demonstrating a high potential for passive forest restoration of unmanaged lands in the matrix.

Abundance and trait-matching both shape interaction frequencies between plants and birds in seed-dispersal networks

Abundance and trait-driven processes have both been identified as potential mechanisms in determining the occurrence of species interactions. However, little is known about how these two mechanisms interact to determine the relative frequencies of interactions between species, and thereby species-specific contributions to ecological functions. Here, we evaluate the effect of both species’ abundance and trait-matching on the occurrence of plant-bird seed dispersal interactions in the Cantabrian Range (northern Spain). For two years at fourteen plots, we independently sampled the abundance and diversity of fleshy-fruited plants and frugivores, as well as the consumption of fruits by birds. We quantified trait-matching by applying a food-web approach based on the log-ratios of species traits relevant to seed dispersal and traits related to fruit-handling and foraging-stratum. We fitted multi-level models incorporating phylogenetic relatedness to identify phylogenetically independent effects of species abundance and trait-matching on interaction frequencies. Fitted models showed that species abundances of both plants and birds always had strong positive effects on interaction frequencies. Trait-matching effects associated with fruit-handling were weak, but consistent across years, whereas those derived from foraging stratum varied across years, according to strong interannual changes in species abundance. Our findings reveal that both species abundance and functional traits are required for a mechanistic understanding of species interactions, as well as for predicting species roles in ecosystems under global change.

Dispersal success of a specialized tropical tree depends on complex interactions among diverse mammalian frugivores

The study of seed dispersal in tropical forest communities is complicated by the high diversity of frugivores and the complex interactions among species and their environments. Determining which species are effective dispersers and which are opportunists with neutral or even negative effects on fruiting plants is a major problem which requires detailed studies focused on particular plant species. In this study we focused on seed dispersal of the wild rambutan (Nephelium melliferum) which supplies energy-rich fruits to primates and other mammals in a seasonal evergreen forest in central Thailand. We hypothesized that gibbons (Hylobates lar) were the most important dispersers and were capable of carrying and defecating seeds away from the tree crown where seeds or seedlings could escape increased distance or density-dependent mortality. We determined the seed dispersal effectiveness of all major arboreal consumers of Nephelium fruit (gibbons, pig-tail monkeys, squirrels) by using data on fruit production and consumption from fruit/seed traps under the canopies of eight sample trees, observations on animals feeding in fruiting trees, and seed deposition data at varying distances from tree crowns. We assessed the survival of seeds and seedlings in relation to distance from the crown by experiments and transect counts. Camera traps were used to detect consumption of seeds on the ground by terrestrial consumers. About half of the ripe fruit crop was harvested by squirrels which gnawed off the outer husk, ate the pulp and dropped intact seeds to the ground. Monkeys chewed and sucked off the pulp and dropped most seeds to the ground not far from the tree. Seeds and intact fruits dropped by squirrels and monkeys supported a large variety of terrestrial mammals most of which were seed predators. Gibbons, which swallow the seed with pulp attached, consumed only 16 % of the fruit crop but were the most effective and reliable seed dispersers overall, and appear to be the most specialized seed dispersal mutualist. Distance-dependent mortality was found in first-year seedlings, as well as evidence that further mortality must space out older saplings prior to recruitment into the tree population, which validates the importance of dispersal by gibbons. However, the great majority of fruits of Nephelium melliferum were consumed by mammalian opportunists and seed predators which interacted with one another in ways which depend on composition of the local community.

Frugivore diversity increases evenness in the seed rain on deforested tropical landscapes

The diversity of tropical forests is strongly shaped by mutualistic interactions involving plants and frugivores that disperse their seeds. However, it is little known how decreases in the diversity of frugivores can affect seed dispersal patterns, plant community composition and species' coexistence in tropical forest landscapes. Here, we investigated the effects of bird frugivore diversity on seed dispersal of rare plant species and on the magnitude of equalizing effects on the seed rain in open areas within 12 fragmented landscapes in the Brazilian Atlantic Forest. We monitored the production of bird‐dispersed seeds and bird abundance in forest fragments, and sampled the seed rain and the activity of birds attracted to experimental tree nuclei established in neighboring pastures. The activity of frugivores in tree nuclei was positively correlated with the diversity of birds recorded in nearby forest fragments, and the seed rain diversity increased with frugivore activity. The proportion of seeds dispersed more frequently than expected by chance in tree nuclei increased linearly with the species' richness of birds. The richness and abundance of active frugivores in deforested areas promoted a seed rain with evenness and diversity up to five times greater than the seed pool available in forest fragments due to the proportional increase in the dispersal of rare plant species and a concomitant proportional decrease in the dispersal of dominant fruiting plants. Furthermore, every additional bird species detected in a site was associated with a 10% increase in the equalizing effect on dispersed seeds' relative abundance. Our results show that the aggregated behavior of avian frugivore communities on deforested areas results in higher species richness in the seed rain of plant communities and underscore the urgency to reduce bird species' loss and the simplification of their communities in tropical landscapes.

Impact of cocoa agricultural intensification on bird diversity and community composition.

To meet the growing demand for chocolate, cocoa (Theobroma cacao) agriculture is expanding and intensifying. Although this threatens tropical forests, cocoa sustainability initiatives largely overlook biodiversity conservation. To inform these initiatives, we analyzed how cocoa agriculture affects bird diversity at farm and landscape scales with a meta‐analysis of 23 studies. We extracted 214 Hedges' g* comparisons of bird diversity and 14 comparisons of community similarity between a forest baseline and 4 farming systems that cover an intensification gradient in landscapes with high and low forest cover, and we summarized 119 correlations between cocoa farm features and bird diversity. Bird diversity declined sharply in low shade cocoa. Cocoa with >30% canopy cover from diverse trees retained bird diversity similar to nearby primary or mature secondary forest but held a different community of birds. Diversity of endemic species, frugivores, and insectivores (agriculture avoiders) declined, whereas diversity of habitat generalists, migrants, nectarivores, and granivores (agriculture associates) increased. As forest decreased on the landscape, the difference in bird community composition between forest and cocoa also decreased, indicating agriculture associates replaced agriculture avoiders in forest patches. Our results emphasize the need to conserve forested landscapes (land sparing) and invest in mixed‐shade agroforestry (land sharing) because each strategy benefits a diverse and distinct biological community.

Ecological drivers of intraspecific variation in seed dispersal services of a common neotropical palm

AbstractThrough frugivory and seed dispersal, vertebrates influence plant demography and forest regeneration. Variation in local habitat surrounding fruiting plants can influence frugivore foraging decisions, thereby creating intraspecific variation in seed dispersal services. However, we have little knowledge of drivers of local variation in frugivory. Here, we investigate factors that may influence frugivore diversity and fruit removal at the level of individual plants. We focus on a common understory palm within a continuous Chocó forest with mixed land‐use histories in Ecuador. The density of pioneer tree species in the genus Cecropia around focal palms was negatively related to fruit removal and the diversity of frugivores visiting palms. This may relate to the fact that the presence and abundance of Cecropia species often indicate the existence and severity of past disturbances. Local Cecropia density was also related to an overall shift in the frugivore community that corresponded with an increase in fruit removal by lower‐quality seed dispersers (rodents). We also found that the local density of fruiting conspecifics was positively related to frugivore diversity, but not fruit removal. Our results provide information on drivers of intraspecific inequalities in plant populations across tropical forest landscapes. The reduction in fruit removal and frugivore diversity associated with local Cecropia abundance suggests that seed dispersal services can be sensitive to fine‐scale variation in habitat structure. Furthermore, because Cecropia are often indicative of past disturbances, this indicates that even small‐scale habitat degradation by humans can have lasting effects by creating localized pockets of forest unfavored by frugivores.Abstract in Spanish is available with online material.

Avian Frugivores Fruit Choice in the Forest Patch of Federal College of Forestry Jos, Plateau State Nigeria

The flora community which attract a different frugivores may be important to the survival of such frugivores. Relationship between avian biodiversity and fruit producing plants may reflect avian fruit choice or preference. This research was done on avian frugivores fruit choice within the forest cover of Federal College of Forestry, Jos in order to study the species and their activity on fruit-producing plants in the site and to compare encounter rate and diversity of avian frugivores across habitats. Bird species were estimated and 212 individual fruit-eating avian species were counted on 28 species of fruit producing plants during this survey. Mean number of fruiteating birds did not differ significantly in the habitats (F63 = 0.1245, Adjusted R2 = -0.02769, P = 0.8832). The abundance of birds in relation to plant species showed a very high significant difference (2 = 339.55, df = 27, P &lt; 0.001). Shannon weiner diversity of birds calculated showed that the diversity in relation to habitat types showed no significant difference (2= 0.045285, df = 2, P = 0.9776). This habitat should therefore be seen as an important habitat for birds and other wildlife.

Direct and plant-mediated effects of climate on bird diversity in tropical mountains.

AimAlthough patterns of biodiversity across the globe are well studied, there is still a controversial debate about the underlying mechanisms and their generality across biogeographic scales. In particular, it is unclear to what extent diversity patterns along environmental gradients are directly driven by abiotic factors, such as climate, or indirectly mediated through biotic factors, such as resource effects on consumers.LocationAndes, Southern Ecuador; Mt. Kilimanjaro, Tanzania.MethodsWe studied the diversity of fleshy‐fruited plants and avian frugivores at the taxonomic level, that is, species richness and abundance, as well as at the level of functional traits, that is, functional richness and functional dispersion. We compared two important biodiversity hotspots in mountain systems of the Neotropics and Afrotropics. We used field data of plant and bird communities, including trait measurements of 367 plant and bird species. Using structural equation modeling, we disentangled direct and indirect effects of climate and the diversity of plant communities on the diversity of bird communities.ResultsWe found significant bottom‐up effects of fruit diversity on frugivore diversity at the taxonomic level. In contrast, climate was more important for patterns of functional diversity, with plant communities being mostly related to precipitation, and bird communities being most strongly related to temperature.Main conclusionsOur results illustrate the general importance of bottom‐up mechanisms for the taxonomic diversity of consumers, suggesting the importance of active resource tracking. Our results also suggest that it might be difficult to identify signals of ecological fitting between functional plant and animal traits across biogeographic regions, since different species groups may respond to different climatic drivers. This decoupling between resource and consumer communities could increase under future climate change if plant and animal communities are consistently related to distinct climatic drivers.

Diversity and distribution of figs in Tripura with four new additional records

Abstract: The genus Ficus L., commonly known as Fig plays an important role in the forest ecosystem, being a keystone species. Taxonomic revision, habitat assessment, and floristic study of the genus Ficus of northeastern region are scanty and still lacking. As the genus is rich in diversity, this region possesses tremendous scope for utilisation of its members, as many species belonging to this genus carry good properties for diverse uses for the benefit of mankind. Therefore, the present study has been undertaken for identification of the collected taxa, diversity assessment of the wild as well as planted species, distribution throughout the state and preparation of a comprehensive checklist along with measures of diverse functions and ecological role of the genus Ficus in Tripura, North-East India. Field survey was conducted between April 2017–August 2018 throughout Tripura and all the locations were marked with GPS which is given in the present distribution map of Ficus in Tripura. This study is based on extensive field survey and specimen collection. Key taxonomic description, both accepted and vernacular names, phenology, and diverse habitat function of all species have been provided. Based on the available literatures, distribution information of the present records were calculated. Evaluation of diverse ecological role were scored based on the published literature and field observations. In the present study, 23 taxa of Ficus have been reported from the study area including four new distribution records. Most of the Ficus species recorded in this study were from moist mixed deciduous and secondary forests. Out of 23 species of Ficus recorded in the present study, seven (7) species belong to evergreen small tree to shrub (F. benghalensis, F. drupacea, F. elastica, F. microcarpa, F. racemosa, F. sarmentosa and F. semicordata); three (3) species recorded are large deciduous tree (F. racemosa, F. religiosa and F. rumphii). Fleshy fruited trees are the most preferable option for survival of frugivores over diverse habitats and thus, plays major role for entire ecosystem restoration. The present work will be useful to understand the critical interactions between plants and frugivore at different trophic levels. Further, Ficus groups tend to have multiple ecological roles, and as a result there exists huge scope to understand the mechanisms of plant functional traits for conservation of threatened frugivore diversity.

Composition of frugivores of Baccaurea ramiflora (Phyllanthaceae) and effects of environmental factors on frugivory in two tropical forests of China and Thailand

Frugivory and seed dispersal are key processes that shape both plant and animal communities, they are important in the maintenance and regeneration of forest ecosystems while threatened by environmental changes. This study investigated the frugivores and environmental factors affecting animal visitation and fruit consumption of the evergreen tree Baccaurea ramiflora (Lour.) in Chinese (Xishuangbanna) and Thai (Mo Singto) tropical forest plots. The two plots differ in their mammal faunas, with more large species (Asian elephant, white-handed gibbon, bears) surviving on the Mo Singto plot. We asked whether these differences could resulted in different seed dispersal patterns on the two plots. Nine individual trees were selected in each plot to record arboreal and ground frugivores of B. ramiflora using camera traps. A total of 27 frugivore species were captured from both forest plots, 15 species in Xishuangbanna and 22 in Mo Singto, with ten species shared in both plots. The major frugivores of B. ramiflora in Xishuangbanna were all pre-dispersal seed predators with little contribution to seed dispersal, including Palla’s squirrel (Callosciurus erythraeus), red-cheeked squirrel (Dremomys rufigenis) and black giant squirrel (Ratufa bicolor). Meanwhile, the major frugivores in Mo Singto were two effective seed dispersers pig-tailed macaque (Macaca leonina) and white-handed gibbon (Hylobates lar), and seed predator black giant squirrel (Ratufa bicolor). The diversity and body size of frugivores in the Xishuangbanna plot were relatively small compared with those in Mo Singto plot. Small-bodied frugivores showed higher activity in Xishuangbanna plot whereas relatively larger frugivores were most active in the Mo Singto plot. The environmental factor that consistently influenced frugivore activity (visitation and consumption of B. ramiflora fruits) was fruit abundance. Ground cover was also a predictor for average visit length and fruit consumption of frugivores. Frugivores visitation rate was higher in Xishuangbanna while average visit length and consumption rates were higher in Mo Singto. The defaunation of large body-size frugivores in Xishuangbanna could have been a result of habitat loss and higher hunting pressure. This may lead to shorter dispersal distances for large-seeded plants, restricting their ability to move across changing landscapes, and threatening their chances of survival over the long term.

Forest amount, not structure, influences fruit removal of two pioneer species in Atlantic forest remnants

AbstractFruit removal is a key component of the seed dispersal process with direct consequences for plant recruitment. Anthropogenic disturbances might affect removal rates by changing frugivore diversity and their behavior. Here, we investigated the effects of local forest structure and landscape context on fruit removal of two common pioneer species of Melastomataceae family, Clidemia capitellata and Henriettea succosa in 14 Atlantic forest sites. We evaluated local forest structure, measured as canopy openness and conspecific density, and the amount of forest cover at the landscape scale measured in 2000 m buffer radius. Our results showed that the landscape context was more important than local features to explain fruit removal. The percentage of fruits removed from both species sharply decreases with forest loss and increases again in highly deforested landscapes. We demonstrate changes in fruit removal due to forest loss and suggest that both Melastomataceae species rely on the absence of other plant species, and consequently, in a less competitive environment to increase fruit removal and seed dispersal.Abstract in Portuguese is available with online material.

Diversity and distribution patterns of medium to large mammals in a silvicultural landscape in south-eastern Brazil

Abstract: Agricultural landscapes cover approximately 35% of Brazil and are the second greatest threat to biodiversity worldwide. In Brazil, seven millions hectars of land is covered with Eucalyptus plantations, which is considered to have low conservation value. However, studies have shown that heterogeneous silvicultural landscapes, made up of Eucalyptus matrices and patches dedicated to conservation, are able to support a considerable diversity of wild mammals. This study aims to assess the diversity and distribution patterns of medium-to-large-sized mammals in a silvicultural landscape in Angatuba, Sao Paulo, Brazil. Nineteen species were detected by camera traps within the study area. Diversity indices did not vary among habitat types (i.e., native vegetation, abandoned pasture and Eucalyptus plantations), suggesting that the species use the landscape as a whole. A relatively diverse range of predator species was found in the area, suggesting that future monitoring programs should focus on predator-prey relationships. A low diversity of frugivores was detected, indicating that management actions should be taken to facilitate their local recovery. Our results stress the fundamental importance of the conservation areas (Permanent Preservation Areas and Legal Reserve) in silvicultural landscapes, as these areas help maintain complexity of the landscape structure.

Direct and indirect effects of plant and frugivore diversity on structural and functional components of fruit removal by birds.

Seed dispersal is an important ecosystem function, but it is contentious how structural and functional diversity of plant and bird communities are associated with seed-dispersal functions. We used structural equation models to test how structural (i.e., abundance, species richness) and functional diversity (i.e., functional dispersion and community-weighted means of functional traits) of fruiting plants and frugivorous birds directly and indirectly influence the respective components of fruit removal. We recorded plant and bird diversity in point counts and observed plant-frugivore interactions in a tropical mountain forest in Ecuador. We also recorded plant and bird morphological traits to calculate measures of functional diversity. We found that fruit abundance had a positive direct effect on bird abundance, which directly and indirectly mediated the abundance of removed fruits. Plant and bird species richness were only directly related to the richness of the removed fruits. Functional dispersion of the plant community was positively associated to that of the bird community and to that of the removed fruits. Consistently, we found positive associations between community-weighted means of plant and bird traits and between community-weighted means of plant traits and that of plants with removed fruits. In contrast, community-weighted means of the bird community were unrelated to that of the removed fruits. Overall, our results suggest that plant abundance directly and indirectly influences fruit removal, likely because of avian fruit tracking. However, we did not find strong links between the functional diversity of the frugivore community and removed fruits, suggesting that other factors in addition to plant-animal trait matching might be important for the functional diversity of removed fruits. Our findings highlight the importance of frugivore abundance for maintaining seed dispersal by animals in tropical forests.

Keragaman Burung Pemakan Buah (Avian Frugivora) di Hutan Dataran Rendah Jayapura, Papua

Frugivorous birds or avian frugivores play important role in seed dispersal cycle and forest regeneration in forest ecosystem of Papua. Despite the high diversity of avian frugivores dwelling in Papuan rainforest, and the fact that this region faces  alarming rate of forest disturbance, little is known of their current presence in the lowland forest habitat. We surveyed the variety of frugivorous birds in three different habitats of lowland forest in Cyclop Mountains Nature Reserve and Nimbokrang District. The methods used were line and point transects and identification was done during the survey. A total of 36 frugivorous birds from eight families was found in both sites.  There were 33 species of 8 families in Nimbokrang forest and 16 species of 7 families were encountered in the Nature Reserve. The primary forest has high diversity of frugivorous birds compared to that in secondary forest and forest garden. It was found that several species of Family Columbidae such as Macropygia amboinensis, Ducula pinon dan Reindwaedtoena reinwardtii  moved and foraged along the forest edge and also visited degraded areas that still provided vegetation trees and perches. These findings might have importance for forest management and reforestation programmes in Papuan lowland forest.Key words: Frugivorous birds, diversity, lowland forest, Mountain Cyclops Nature Reserve, Nimbokrang.

Bird responses to land use change: guild diversity in a Kenyan coastal forest and adjoining habitats

ABSTRACTLand use change can have profound effects on forest ecology, particularly on the avian community. Arabuko-Sokoke Forest, one of the Important Bird Areas (IBAs) in Kenya, is under threat due to ongoing land use change in the surroundings that could affect species composition of many bird guilds. However, information on the response of different guilds in tropical land use systems is sparse in Africa. We examined the effects of land use on bird guilds in primary forest (Arabuko-Sokoke Forest), adjoining plantations, and neighbouring farmland. Point counts were distributed equally in the three land use systems to survey bird populations. A total of 2600 bird observations was recorded, representing 97 species in five main feeding guilds (frugivores, nectarivores, insectivores, carnivores, and granivores). Granivores were most abundant and diverse in farmland, while carnivores (primarily raptors) utilised all habitats. Insectivores were most diverse in primary forest where vertical heterogeneity of the vegetation and the presence of large fruiting trees significantly influenced their occurrence. Specialist nectarivores were most frequent in primary forest, whereas occasional nectarivores were less abundant there. Contrary to expectation, frugivore diversity showed no significant effect of land use.