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Fleshy fruits can be divided between climacteric (CL, showing a typical rise in respiration and ethylene production with ripening after harvest) and non-climacteric (NC, showing no rise). However, despite the importance of the CL/NC traits in horticulture and the fruit industry, the evolutionary significance of the distinction remains untested. In this study, we tested the hypothesis that NC fruits, which ripen only on the plant, are adapted to tree dispersers (feeding in the tree), and CL fruits, which ripen after falling from the plant, are adapted to ground dispersers. A literature review of 276 reports of 80 edible fruits found a strong correlation between CL/NC traits and the type of seed disperser: fruits dispersed by tree dispersers are more likely to be NC, and those dispersed by ground dispersers are more likely to be CL. NC fruits are more likely to have red–black skin and smaller seeds (preferred by birds), and CL fruits to have green–brownish skin and larger seeds (preferred by large mammals). These results suggest that the CL/NC traits have an important but overlooked seed dispersal function, and CL fruits may have an adaptive advantage in reducing ineffective frugivory by tree dispersers by falling before ripening.

Ongoing environmental changes are affecting physical, chemical and biological soil components. Evidence of impacts of soil changes on pollinators' and seed dispersers' behaviour, fitness and density is scarce, but growing. Here, we reviewed information on such impacts and on a number of mechanisms that may explain its propagation, taking into account the full range of resources required by the large and diverse number of species of these two important functional groups. We show that while there is substantial evidence on the effects of soil nitrogen enrichment and changes in soil water content on the quality and quantity of floral and fruit resources, little is known on the effects of changes of other soil properties (e.g. soil pH, soil structure, other nutrients). Also, the few studies showing correlations between soil changes and pollinator and seed disperser foraging behaviour or fitness do not clearly identify the mechanisms that explain such correlation. Finally, most studies (including those with nitrogen and water) are local and limited to a small number of species, and it remains unclear how variable such effects are across time and geographical regions, and the strength of interactive effects between soil properties. Increasing research on this topic, taking into consideration how impacts propagate through species interaction networks, will provide essential information to predict impacts of ongoing environmental changes and help guide conservation plans that aim to minimize impacts on ecosystem functioning.This article is part of the theme issue ‘The role of soils in delivering Nature's Contributions to People’.

Human presence is becoming increasingly ubiquitous, but the influence this has on the seed dispersal services performed by frugivorous animals is largely unknown. The New Zealand weka ( Gallirallus australis ) is an inquisitive flightless rail that frequently congregates in areas of high human use. Weka are important seed dispersers, yet the seed dispersal services they provide are still poorly understood. We estimated seed dispersal distances of weka for two plant species ( Prumnopitys ferruginea and Elaeocarpus dentatus ) and tested how human interaction affected these dispersal distances. We estimated weka seed dispersal distances by combining GPS data from 39 weka over three sites with weka seed retention time data in a mechanistic model. The mean seed retention times were extremely long (38–125 h). Weka were highly effective dispersers, dispersing 93–96% of seeds away from parent canopies, and 1% of seeds over 1 km. However, we found evidence of a significant human impact on the seed dispersal distances of weka, with birds occupying areas of high human use performing 34.8–40.9% shorter distances than their more remote counterparts. This represents an example of cryptic function loss, where although weka are still present in the ecosystem, their seed dispersal services are impaired by human interaction.

A long-standing hypothesis in ecology and evolution is that trichromatic colour vision (the ability to distinguish red from green) in frugivorous primates has evolved as an adaptation to detect conspicuous (reddish) fruits. This could provide a competitive advantage over dichromatic frugivores which cannot distinguish reddish colours from a background of green foliage. Here, we test whether the origin, distribution and diversity of trichromatic primates is positively associated with the availability of conspicuous palm fruits, i.e. keystone fruit resources for tropical frugivores. We combine global data of colour vision, distribution and phylogenetic data for more than 400 primate species with fruit colour data for more than 1700 palm species, and reveal that species richness of trichromatic primates increases with the proportion of palm species that have conspicuous fruits, especially in subtropical African forests. By contrast, species richness of trichromats in Asia and the Americas is not positively associated with conspicuous palm fruit colours. Macroevolutionary analyses further indicate rapid and synchronous radiations of trichromats and conspicuous palms on the African mainland starting 10 Ma. These results suggest that the distribution and diversification of African trichromatic primates is strongly linked to the relative availability of conspicuous (versus non-conspicuous) palm fruits, and that interactions between primates and palms are related to the coevolutionary dynamics of primate colour vision systems and palm fruit colours. publishedVersion

Frugivores play differing roles in shaping dispersal patterns yet seed dispersal distance is rarely quantified across entire communities. We model seed dispersal distance using gut passage times and bird movement for the majority (39 interactions) of known bird–tree interactions on the island of Saipan to highlight differences in seed dispersal distances provided by the five avian frugivores. One bird species was found to be a seed predator rather than a disperser. The remaining four avian species dispersed seeds but differences in seed dispersal distance were largely driven by interspecific variation in bird movement rather than intraspecific variation in gut passage times. The median dispersal distance was at least 56 m for all species-specific combinations, indicating all species play a role in reducing high seed mortality under the parent tree. However, one species—the Micronesian Starling—performed 94% of dispersal events greater than 500 m, suggesting this species could be a key driver of long-distance dispersal services (e.g. linking populations, colonizing new areas). Assessing variation in dispersal patterns across this network highlights key sources of variation in seed dispersal distances and suggests which empirical approaches are sufficient for modelling how seed dispersal mutualisms affect populations and communities.

To date, wake measurements using particle image velocimetry (PIV) of bats in flight have studied only three bat species, all fruit and nectar feeders. In this study, we present the first wake structure analysis for an insectivorous bat.Tadarida brasiliensis, the Brazilian free-tailed bat, is an aerial hunter that annually migrates long distances and also differs strikingly from the previously investigated species morphologically. We compare the aerodynamics ofT. brasiliensiswith those of other, frugivorous bats and with common swifts,Apus apus, a bird with wing morphology, kinematics and flight ecology similar to that of these bats. The comparison reveals that, for the range of speeds evaluated, the cyclical pattern of aerodynamic forces associated with a wingbeat shows more similarities betweenT. brasiliensisandA. apusthan betweenT. brasiliensisand other frugivorous bats.

Protein is a limiting resource that is essential to the growth, maintenance and reproduction of tropical frugivores, yet few studies have examined how wild animals maintain protein balance. During chronic periods of fruit scarcity, Bornean orangutans ( Pongo pygmaeus ) often catabolize their own fat reserves despite unusually low metabolic requirements. Such energy deficits suggest a marginal existence, and raise the possibility that orangutans also endure periods of negative protein balance. To test this hypothesis, we conducted the first study of protein cycling in a wild primate. Our five year analysis of urinary metabolites revealed evidence of protein recycling when fruit was scarce. During these periods, orangutans consumed more leaves and bark, proteinaceous but tough foods that yielded a mean daily intake of 1.4 g protein kg −1 metabolic mass. Such an amount is inadequate for humans and one-tenth the intake of mountain gorillas, but sufficient to avert, perhaps narrowly, a severe protein deficit. Our findings highlight the functional and adaptive value of traits that maximize protein assimilation during periods of ecological exigency.

Although global declines in frugivores may disrupt seed dispersal mutualisms and inhibit plant recruitment, quantifying the likely reduction in plant regeneration has been difficult and rarely attempted. We use a manipulative factorial experiment to quantify dependence of recruitment on dispersal (i.e. fruit pulp removal and movement of seed away from parental area) in two large-seeded New Zealand tree species. Complete dispersal failure would cause a 66 to 81 per cent reduction in recruitment to the 2-year-old seedling stage, and synergistic interactions with introduced mammalian seed and seedling predators increase the reduction to 92 to 94 per cent. Dispersal failure reduced regeneration through effects on seed predation, germination and (especially) seedling survival, including distance- and density-dependent (Janzen–Connell) effects. Dispersal of both species is currently largely dependent on a single frugivore, and many fruits today remain uneaten. Present-day levels of frugivore loss and mammal seed and seedling predators result in 57 to 84 per cent fewer seedlings after 2 years. Our study demonstrates the importance of seed dispersal for local plant population persistence, and validates concerns about the community consequences of frugivore declines.

The ecological function of fruit colour has been the focus of many studies. The most commonly tested hypothesis is that fruit colour has evolved to facilitate detection by seed-dispersing animals. We tested whether distributions of fruit colours are consistent with the hypothesis that colour is an evolved signal to seed dispersers using a comparative community approach. We compared the contrast between ripe fruits and leaf backgrounds at two sites, one in Madagascar where seed dispersers are primarily night-active, red–green colour-blind lemurs, and the other in Uganda, where most vertebrate seed dispersers are day-active primates and birds with greater capacity for colour vision. We show that fruits in Uganda have higher contrast against leaf background in the red–green and luminance channels whereas fruits in Madagascar contrast more in the yellow–blue channel. These results indicate that fruit colour has evolved to contrast against background leaves in response to the visual capabilities of local seed disperser communities.

Conservation has long focused on preserving or restoring pristine ecosystems. However, understanding and managing novel ecosystems has grown in importance as they outnumber pristine ecosystems worldwide. While non-native species may be neutral or detrimental in pristine ecosystems, it is possible that even notorious invaders could play beneficial or mixed roles in novel ecosystems. We examined the effects of two long-established non-native species—Philippine deer ( Rusa marianna ) and feral pigs ( Sus scrofa )—in Guam, Micronesia, where native vertebrate frugivores are functionally absent leaving forests devoid of seed dispersers. We compared the roles of deer and pigs on seedling survival, seed dispersal and plant community structure in limestone karst forests. Deer, even at low abundances, had pronounced negative impacts on forest communities by decreasing seedling and vine abundance. By contrast, pigs showed no such relationship. Also, many viable seeds were found in pig scats, whereas few were found in deer scats, suggesting that pigs, but not deer, provide an ecosystem function—seed dispersal—that has been lost from Guam. Our study presents a discrepancy between the roles of two non-native species that are traditionally managed as a single entity, suggesting that ecological function, rather than identity as a non-native, may be more important to consider in managing novel systems.

Seed dispersal is a key evolutionary process and a central theme in the population ecology of terrestrial plants. The primary producers of most land-based ecosystems are propagated by and maintained through various mechanisms of seed dispersal that involve both abiotic and biotic modes of transportation. By far the most common biotic seed transport mechanism is zoochory, whereby seeds, or fruits containing them, are dispersed through the activities of animals. Rodents are one group of mammals that commonly prey on seeds (granivores) and play a critical, often destructive, role in primary dispersal and the dynamics of plant communities. In North America, geomyid, heteromyid and some sciurid rodents have specialized cheek pouches for transporting seeds from plant source to larder, where they are often eliminated from the pool of plant propagules by consumption. These seed-laden rodents are commonly consumed by snakes as they forage, but unlike raptors, coyotes, bobcats, and other endothermic predators which eat rodents and are known or implicated to be secondary seed dispersers, the role of snakes in seed dispersal remains unexplored. Here, using museum-preserved specimens, we show that in nature three desert-dwelling rattlesnake species consumed heteromyids with seeds in their cheek pouches. By examining the entire gut we discovered, furthermore, that secondarily ingested seeds can germinate in rattlesnake colons. In terms of secondary dispersal, rattlesnakes are best described as diplochorous. Because seed rescue and secondary dispersal in snakes has yet to be investigated, and because numerous other snake species consume granivorous and frugivorous birds and mammals, our observations offer direction for further empirical studies of this unusual but potentially important channel for seed dispersal.

Biological invasions can alter direct and indirect interactions between species, generating far-reaching changes in ecological networks that affect key ecological functions. We used model and real fruit assays to show that the invasion and formation of high-density supercolonies by the yellow crazy ant (YCA), Anoplolepis gracilipes , disrupt frugivory by endemic birds on Christmas Island, Indian Ocean. The overall handling rates of model fruits by birds were 2.2–2.4-fold lower in ant-invaded than in uninvaded rainforest, and pecking rates by two bird species declined by 2.6- and 4.5-fold, respectively. YCAs directly interfered with frugivory; their experimental exclusion from fruiting displays increased fruit handling threefold to sixfold, compounding indirect effects of ant invasion on resources and habitat structure that influence bird abundances and behaviours. This invasive ant, whose high densities are sustained through mutualism with introduced scale insects, rapidly decreases fruit handling by endemic island birds and may erode a key ecological function, seed dispersal. Because most other invasive ant species form expansive, high-density supercolonies that depend in part on association with hemipteran mutualists, the effects that we report here on avian frugivore–plant associations may emerge across their introduced ranges.

Mutualistic networks involving plants and their pollinators or frugivores have been shown recently to exhibit a particular asymmetrical organization of interactions among species called nestedness: a core of reciprocal generalists accompanied by specialist species that interact almost exclusively with generalists. This structure contrasts with compartmentalized assemblage structures that have been verified in antagonistic food webs. Here we evaluated whether nestedness is a property of another type of mutualism—the interactions between ants and extrafloral nectary-bearing plants—and whether species richness may lead to differences in degree of nestedness among biological communities. We investigated network structure in four communities in Mexico. Nested patterns in ant–plant networks were very similar to those previously reported for pollination and frugivore systems, indicating that this form of asymmetry in specialization is a common feature of mutualisms between free-living species, but not always present in species-poor systems. Other ecological factors also appeared to contribute to the nested asymmetry in specialization, because some assemblages showed more extreme asymmetry than others even when species richness was held constant. Our results support a promising approach for the development of multispecies coevolutionary theory, leading to the idea that specialization may coevolve in different but simple ways in antagonistic and mutualistic assemblages.

The exceptional diversity of neotropical bat communities is sustained by an intricate partitioning of available resources among the member species. Trophical specialization is considered an important evolutionary avenue towards niche partitioning in neotropical phyllostomid bats. From an ancestral insectivorous condition, phyllostomids evolved into highly specialized frugivorous, carnivorous, nectarivorous, piscivorous and even sanguivorous species. Previously, correlations between cranial morphology and trophic ecology within this group have been documented. Here, we examine the evolutionary relationships between bite force and head shape in over 20 species of bats from a single tropical savannah bat community. The results show that bite force increases exponentially with body size across all species examined. Despite the significant differences between large dietary groups using traditional analysis (i.e. non-phylogenetic) and the strong evolutionary correlations between body mass and bite force, phylogenetic analyses indicated no differences in bite performance between insectivorous, omnivorous and frugivorous bats. Comparisons of three species with highly specialized feeding habits (nectarivory, piscivory and sanguivory) with the rest of the species in the community indicate that specialization into these niches comes at the expense of bite performance and, hence, may result in a reduction of the trophic niche breadth.

We present a formal model of Janzen's influential theory that competition for resources between microbes and vertebrates causes microbes to be selected to make these resources unpalatable to vertebrates. That is, fruit rots, seeds mould and meat spoils, in part, because microbes gain a selective advantage if they can alter the properties of these resources to avoid losing the resources to vertebrate consumers. A previous model had failed to find circumstances in which such a costly spoilage trait could flourish; here, we present a simple analytic model of a general situation where costly microbial spoilage is selected and persists. We argue that the key difference between the two models lies in their treatments of microbial dispersal. If microbial dispersal is sufficiently spatially constrained that different resource items can have differing microbial communities, then spoilage will be selected; however, if microbial dispersal has a strong homogenizing effect on the microbial community then spoilage will not be selected. We suspect that both regimes will exist in the natural world, and suggest how future empirical studies could explore the influence of microbial dispersal on spoilage.

Unlike humans, birds perceive ultraviolet (UV) light (320 to 400 nm), a waveband which is known to play a role in avian mate choice. However, less attention has been paid to the role of UV light in avian foraging. Some blue, violet and black berries reflect UV light. The colour of berries might be an effective advertisement for avian seed dispersers and indicate the stage of fruit ripeness. We conducted an experiment to test how the UV reflection of berries affects birds' foraging. Redwings were allowed to choose between UV-reflecting bilberries and rubbed bilberries (UV reduced) in the presence and absence of UV light. We used wild-caught adult and hand-raised juvenile birds to assess possible differences between experienced and naive birds. We found that adult redwings preferred UV-reflecting berries when UV illumination was present, but when UV illumination was absent, they did not distinguish between the two berry types. Our study therefore shows, for the first time, that UV wavelengths are used when birds feed on fruit. However, naive birds showed no preferences, suggesting that age and/or learning may affect frugivore preference for UV reflectance.

Land-use change is one of the main drivers of current and likely future biodiversity loss. Therefore, understanding how species are affected by it is crucial to guide conservation decisions. Species respond differently to land-use change, possibly related to their traits. Using pan-tropical data on bird occurrence and abundance across a human land-use intensity gradient, we tested the effects of seven traits on observed responses. A likelihood-based approach allowed us to quantify uncertainty in modelled responses, essential for applying the model to project future change. Compared with undisturbed habitats, the average probability of occurrence of bird species was 7.8 per cent and 31.4 per cent lower, and abundance declined by 3.7 per cent and 19.2 per cent in habitats with low and high human land-use intensity, respectively. Five of the seven traits tested affected the observed responses significantly: long-lived, large, non-migratory, primarily frugivorous or insectivorous forest specialists were both less likely to occur and less abundant in more intensively used habitats than short-lived, small, migratory, non-frugivorous/insectivorous habitat generalists. The finding that species responses to land use depend on their traits is important for understanding ecosystem functioning, because species' traits determine their contribution to ecosystem processes. Furthermore, the loss of species with particular traits might have implications for the delivery of ecosystem services.

When species within guilds perform similar ecological roles, functional redundancy can buffer ecosystems against species loss. Using data on the frequency of interactions between fish and fruit, we assessed whether co-occurring frugivores provide redundant seed dispersal services in three species-rich Neotropical wetlands. Our study revealed that frugivorous fishes have generalized diets; however, large-bodied fishes had greater seed dispersal breadth than small species, in some cases, providing seed dispersal services not achieved by smaller fish species. As overfishing disproportionately affects big fishes, the extirpation of these species could cause larger secondary extinctions of plant species than the loss of small specialist frugivores. To evaluate the consequences of frugivore specialization for network stability, we extracted data from 39 published seed dispersal networks of frugivorous birds, mammals and fish (our networks) across ecosystems. Our analysis of interaction frequencies revealed low frugivore specialization and lower nestedness than analyses based on binary data (presence–absence of interactions). In that case, ecosystems may be resilient to loss of any given frugivore. However, robustness to frugivore extinction declines with specialization, such that networks composed primarily of specialist frugivores are highly susceptible to the loss of generalists. In contrast with analyses of binary data, recently developed algorithms capable of modelling interaction strengths provide opportunities to enhance our understanding of complex ecological networks by accounting for heterogeneity of frugivore–fruit interactions.

The positive link between biodiversity and ecosystem functioning is a current paradigm in ecological science. However, little is known of how different attributes of species assemblages condition the quality of many services in real ecosystems affected by human impact. We explore the links between the attributes of a frugivore assemblage and the quantitative and qualitative components of its derived ecosystem service, seed dispersal, along a landscape-scale gradient of anthropogenic forest loss. Both the number and the richness of seeds being dispersed were positively related to frugivore abundance and richness. Seed dispersal quality, determined by the fine-scale spatial patterns of seed deposition, mostly depended on frugivore richness. In fact, richness was the only attribute of the frugivore assemblage affecting the probability of seed dispersal into deforested areas of the landscape. The positive relationships between frugivore richness per se (i.e. independent of frugivore abundance and composition) and all components of seed dispersal suggest the existence of functional complementarity and/or facilitation between frugivores. These links also point to the whole assemblage of frugivores as a conservation target, if we aim to preserve a complete seed dispersal service and, hence, the potential for vegetation regeneration and recovery, in human-impacted landscapes.

How ecological opportunity relates to diversification is a central question in evolutionary biology. However, there are few empirical examples of how ecological opportunity and morphological innovation open new adaptive zones, and promote diversification. We analyse data on diet, skull morphology and bite performance, and relate these traits to diversification rates throughout the evolutionary history of an ecologically diverse family of mammals (Chiroptera: Phyllostomidae). We found a significant increase in diversification rate driven by increased speciation at the most recent common ancestor of the predominantly frugivorous subfamily Stenodermatinae. The evolution of diet was associated with skull morphology, and morphology was tightly coupled with biting performance, linking phenotype to new niches through performance. Following the increase in speciation rate, the rate of morphological evolution slowed, while the rate of evolution in diet increased. This pattern suggests that morphology stabilized, and niches within the new adaptive zone of frugivory were filled rapidly, after the evolution of a new cranial phenotype that resulted in a certain level of mechanical efficiency. The tree-wide speciation rate increased non linearly with a more frugivorous diet, and was highest at measures of skull morphology associated with morphological extremes, including the most derived Stenodermatines. These results show that a novel stenodermatine skull phenotype played a central role in the evolution of frugivory and increasing speciation within phyllostomids.

In lowland dipterocarp forest in Sabah, Malaysia, most primary forest bird species were present in areas selectively logged eight years previously. However, certain taxa, notably flycatchers, woodpeckers, trogons and wren-babblers, became comparatively rare. In contrast, nectarivorous and opportunistic frugivorous species were significantly more abundant. Few species appeared to change foraging height, but netting rates suggest that the activity of some species had increased, or that some birds ranged over larger areas after logging. Although there is still much to be learned about the survival of birds in logged forest, large areas of this habitat are important for bird conservation. However, the susceptibility of logged forest to fire, and our present incomplete understanding of bird behaviour and population dynamics in logged forests mean that they should not be considered by conservationists as alternatives to reserves of primary forest.

Angiosperm diversification has resulted in a vast array of plant morphologies. Only recently has it been appreciated that diversification might have proceeded quite differently for the two key diagnostic structures of this clade, flowers and fruits. These structures are hypothesized to have experienced different selective pressures via their interactions with animals in dispersal mutualisms, resulting in a greater amount of morphological diversification in animal-pollinated flowers than in animal-dispersed fruits. I tested this idea using size and colour traits for the flowers and fruits of 472 species occurring in three floras (St John, Hawaii and the Great Plains). Phylogenetically controlled analyses of nearest-neighbour distances in multidimensional trait space matched the predicted pattern: in each of the three floras, flowers were more divergent from one another than were fruits. In addition, the spacing of species clusters differed for flowers versus fruits in the flora of St John, with clusters in flower space more divergent than those in fruit space. The results are consistent with the idea that a major driver of angiosperm diversification has been stronger selection for divergent floral morphology than for divergent fruit morphology, although genetic, physiological and ecological constraints may also play a role.

Bird colonization of Anak Krakatau in the 1980s serves as a model for the early colonization processes, which were mostly undocumented, that occurred on the archipelago in the first two decades of this century. Anak Krakatau, which emerged from the sea in 1930, also provides an opportunity to study the formation of an avian community de novo . Thirty-seven species of birds have been recorded since 1951. Shore birds and aerial insectivores were the first species to exploit the newly emerged island. Plant succession, which is proceeding at different rates on different parts of the island, has provided niches for birds to permanently colonize. Species of open habitats ( Caprimulgus affinis, Centropus bengalensis ) were the first colonists, followed next by ecological generalists with good dispersal ability ( Pycnonotus Goiavier, Halcyon chloris ) ; the next species were those that exploit casuarina woodland and forest and the most recent wave of colonists have been frugivores that arrived after figs began to bear fruit in 1985. Three raptors that hunt on the island have limited the colonization of three large frugivores. Most, but not all, colonists have come from the older islands, including those species denied open habitats by plant succession. Comparisons are made with the bird colonization of Rakata during the first two decades of this century. Most birds on Anak Krakatau are insectivores and are restricted to two areas of trees some 12 hectares in total. Foraging methods and sites show little overlap, but dietary analysis in August 1986 showed some common prey items. The very high density of insectivores may be a function of insect abundance on the island and high fecundity and tolerance of crowding by early bird colonists.

Ripe fruit offer readily available nutrients for many animals, including fruit fly larvae (Diptera: Tephritidae) and their associated rot-inducing bacteria. Yet, during most of their ontogeny, fruit remain chemically defended and effectively suppress herbivores and pathogens by high levels of secondary metabolites. Olive flies ( Bactrocera oleae ) are uniquely able to develop in unripe olives. Unlike other frugivorous tephritids, the larvae maintain bacteria confined within their midgut caeca. We examined the interaction between larvae, their associated bacteria, and fruit chemical defence, hypothesizing that bacterial contribution to larval development is contingent on the phenology of fruit defensive chemistry. We demonstrate that larvae require their natural complement of bacteria ( Candidatus Erwinia dacicola: Enterobacteriaceae) in order to develop in unripe olives. Conversely, when feeding on ripe fruit, larval development proceeds independently of these bacteria. Our experiments suggest that bacteria counteract the inhibitory effect of oleuropein—the principal phenolic glycoside in unripe olives. In light of these results, we suggest that the unique symbiosis in olive flies, compared with other frugivorous tephritids, is understood by considering the relationship between the fly, bacteria and fruit chemistry. When applied in an evolutionary context, this approach may also point out the forces which shaped symbioses across the Tephritidae.

Selective logging is one of the most common forms of forest use in the tropics. Although the effects of selective logging on biodiversity have been widely studied, there is little agreement on the relationship between life-history traits and tolerance to logging. In this study, we assessed how species traits and logging practices combine to determine species responses to selective logging, based on over 4000 observations of the responses of nearly 1000 bird species to selective logging across the tropics. Our analysis shows that species traits, such as feeding group and body mass, and logging practices, such as time since logging and logging intensity, interact to influence a species' response to logging. Frugivores and insectivores were most adversely affected by logging and declined further with increasing logging intensity. Nectarivores and granivores responded positively to selective logging for the first two decades, after which their abundances decrease below pre-logging levels. Larger species of omnivores and granivores responded more positively to selective logging than smaller species from either feeding group, whereas this effect of body size was reversed for carnivores, herbivores, frugivores and insectivores. Most importantly, species most negatively impacted by selective logging had not recovered approximately 40 years after logging cessation. We conclude that selective timber harvest has the potential to cause large and long-lasting changes in avian biodiversity. However, our results suggest that the impacts can be mitigated to a certain extent through specific forest management strategies such as lengthening the rotation cycle and implementing reduced impact logging.

The short-tailed fruit bat, Carollia perspicillata , lives in groups in tree hollows and caves. To investigate whether these roosts might serve as information centres, we tested whether individuals' preferences for novel foods could be enhanced through social learning at the roost. We also determined whether socially learned preferences for novel foods were reversed through interaction with other roost mates by simulating changes in available food resources such as those associated with variations in timing of fruit production in different plant species. Bats exhibited socially induced preferences that were readily reversible. We suggest that for frugivorous bats, roosts can serve as centres for information exchange about novel and familiar, ephemeral foods without requiring conspecific recruitment to these resources.