Biology subjects

Jordano, P.

Publications and source records attributed to Jordano, P..

11 recordsLinked to original sources

bioRxiv2026

A comparative analysis of fruit feeding among Mediterranean passerine birds

1Fleshy fruits underpin a major mutualistic pathway linking plants and birds in Mediterranean scrublands, yet we still lack a mechanistic understanding of how ecomorphological and digestive traits constrain fruit use, foraging behaviour, and ultimately the effectiveness of avian seed dispersal. Here we assemble an integrative dataset for 146 Iberian bird species combining external morphology, digestive anatomy, diet composition, and fine-grained observations of fruit foraging and handling obtained from standardized focal watches and camera traps at fruiting plants. We classify species into five functional feeding groups (seed dispersers, pulp consumers, pulp consumer-dispersers, pulp consumer-seed predators, non-frugivores) and ask how suites of traits map onto these feeding modes and onto quantitative metrics of frugivory and feeding rate. Across species, the proportion of diet volume made up by fleshy fruits increases with gape width and faster food transit, and decreases with larger gizzards and longer intestines, indicating a tight coupling between frugivory and traits that enable rapid processing of dilute, pulp-rich food. A small subset of traits (body mass, gape width, gizzard mass, transit time) explains over half of the interspecific variation in fruit consumption, with ecomorphological and digestive characters contributing roughly equally to explained variance. Per-visit feeding rates and numbers of fruits ingested per visit scale positively with body mass, and canonical discriminant analysis reveals distinct multivariate trait syndromes separating seed dispersers from pulp consumers, seed predators, and non-frugivores. These trait syndromes, and the associated differences in handling mode and feeding speed, provide a mechanistic link between individual-level foraging decisions and the sparsity, asymmetry, and effectiveness of plant-frugivore interaction networks in Mediterranean systems. Our results highlight how trait-based constraints shape not only who interacts with whom, but also how efficiently seeds are removed and dispersed across a diverse frugivore assemblage.

ecology↗

bioRxiv2025

The biodiversity of plant-frugivore interactions: types, functions, and consequences

Pairwise plant-frugivore mutualistic interactions build up into mega-diverse networks involving dozens of interacting species, being the most generalized among free-living species. These mutualisms consist of food provisioning by plants and, their counterpart, plant propagule (seeds) movement by the animals, being crucial for the natural vegetation regeneration in many ecosystems. Yet we are far from understanding which part of this enormous interaction biodiversity is needed for their maintenance. I overview the diversity of interaction modes involved in these mutualisms, the main components of the seed dispersal services, and their functional diversity. I examine how interaction richness covaries with partner species richness at different scales, resulting in variable patterns of species complementarities in terms of seed dispersal effects. The functionality of most generalized plant-frugivore mutualisms relies on complementarity of effects across a high diversity of partners, yet frequently depends on just a distinct subset of them, resulting in high functional redundancy. Two distinct aspects are relevant: 1) variable quantitative effects among species; 2) variable pairwise-interaction outcomes, between the extremes of antagonism and mutualism. Frugivory, occurring at the final stage of each plant reproductive episode, entails a large, cumulative, effect of other biotic interactions occurring at earlier stages (e.g., floral herbivory, pollination, pre-dispersal fruit damage). I examine how plant-frugivore interactions mix-up with the whole biotic interactome of a plant, using the Prunus mahaleb system as a case study. The effects of distinct subsets of frugivores combine with different sets of antagonistic and mutualistic partners in other interactions, yet having a lasting signal on final seed dispersal success. Abbreviated abstractPairwise plant-frugivore mutualistic interactions aggregate into highly diverse networks crucial for seed dispersal and ecosystem regeneration, but the exact subset of interactions essential to maintain these systems remains unclear. The functionality of these mutualisms depends on complementary effects among many species, though often only a few key partners drive seed dispersal, producing both high diversity and redundancy. The outcomes of these interactions--ranging from mutualism to antagonism-- are cumulative, as frugivory at the end of the reproductive cycle incorporates the influences of other biotic interactions throughout earlier plant stages, as illustrated by the Prunus mahaleb case study. Significance statementPairwise plant-frugivore mutualistic interactions aggregate into highly diverse networks crucial for seed dispersal and ecosystem regeneration, but the exact subset of interactions essential to maintain these systems remains unclear. Outcomes of these interactions--ranging from mutualism to antagonism-- are cumulative, as frugivory at the end of the reproductive cycle incorporates the influences of other biotic interactions throughout earlier plant stages. This study highlights the combined effects of plant-frugivore interactions within the whole plant interactome.

ecology↗

bioRxiv2025

A machine learning application to camera-traps: robust species interactions datasets for analysis of mutualistic networks

Recording and quantifying ecological interactions is vital for understanding biodiversity, ecosystem stability, and resilience. Camera traps have become a key tool for documenting plant-animal interactions, especially when combined with computer vision (CV) technology to handle large datasets. However, creating comprehensive ecological interaction databases remains challenging due to labor-intensive processes and a lack of standardization. While CV aids in data processing, it has limitations, including information loss, which can impact subsequent analyses. This study presents a detailed methodology to streamline the creation of robust ecological interaction databases using CV-enhanced tools. It highlights potential pitfalls in applying CV models across different contexts, particularly for specific plant and animal species. The approach aligns with existing camera trap standards and incorporates complex network analysis tools. It also addresses a gap in ecological research by extending the methodology to behavioral studies using video-based image recognition, as most current studies rely on still images. The study evaluates CVs performance in estimating species interaction frequency (PIE) and its ecological implications, with examples of plant-frugivores interactions for seed dispersal. Results show that up to 10% of pairwise interactions may be missed with CV, with information loss varying among focal species and individual plants. This poses challenges for individual-based approaches, where unbiased data collection requires extra caution. However, the loss is minimal compared to the vast data CV enables researchers to gather. For community-level approaches, only three out of 344 unique pairwise interactions were missed, and overall estimates of both PIEs and interaction strengths remained largely unaffected. The methodology provides a valuable resource for ecologists seeking to document ecological interactions efficiently. It offers guidelines for collecting reliable data while addressing CVs limitations in capturing unbiased species interaction data. Despite its constraints, CV significantly enhances the ability to gather large-scale interaction data, particularly at the community level, making it an indispensable tool for ecological research.

ecology↗

bioRxiv2024

Integrating intraspecific variation into population dynamics reveals how interacting species persist in mutualistic communities

Mutualistic interactions among organisms are fundamental to the origin and maintenance of bio-diversity. Yet, the study of community dynamics often relies on species-level values, ignoring the effects of intraspecific variation. We propose a theoretical framework for evaluating the extent to which variation within populations can influence species persistence in mutualistic systems. Next, drawing from detailed empirical data on plant-pollinator interactions and plant fitness, we quantify intraspecific variation in the mutualistic benefits received by plants and incorporate this variation into estimations of structural stability, a robust theoretical measure of species likelihood of persistence. Through explicit consideration of intraspecific variation, we demonstrate that, in the absence of heterospecific plant competitors, plant populations composed of specialized individuals promote the persistence of the plant species they belong to and their associated pollinator community. However, these positive effects do not hold when plant species compete with a broader plant community. In this case, having more heterogeneous mixtures of plant individuals (i.e., both specialized and generalized) is more beneficial for a populations persistence. By integrating the proposed framework with empirical data, we are able to explicitly account for individual-level variation, opening the door to a better understanding of the mechanisms promoting biodiversity in mutualistic communities.

ecology↗

bioRxiv2024

Downscaling mutualistic networks from species to individuals reveals consistent interaction niches and roles within plant populations

Species-level networks emerge as the combination of interactions spanning multiple individuals, and their study has received considerable attention over the past 30 years. However, less is known about the structure of interaction configurations within species, even though individuals are the actual interacting units in nature. We compiled 46 empirical, individual-based, interaction networks on plant-animal seed dispersal mutualisms, comprising 1037 plant individuals across 29 species from various regions. We compared the structure of individual-based networks to that of species-based networks and, by extending the niche concept to interaction assemblages, we explored individual plant specialization. Using a Bayesian framework to account for uncertainty derived from sampling, we examined how plant individuals "explore" the interaction niche of their populations. Both individual-based and species-based networks exhibited high variability in network properties, lacking remarkable structural and topological differences between them. Within populations, frugivores interaction allocation among plant individuals was highly heterogeneous, with one to three frugivore species dominating interactions. Regardless of species or bioregion, plant individuals displayed a variety of interaction profiles across populations, with a consistently small percentage of individuals playing a central role and exhibiting high diversity in their interaction assemblage. Plant populations showed variable mid to low levels of niche specialization; and individuals interaction niche "breadth" accounted for 70% of the population interaction diversity, on average. Our results highlight how downscaling from species to individual-based networks helps understanding the structuring of interactions within ecological communities and provide an empirical basis for the extension of niche theory to complex mutualistic networks. Significance StatementEcological interactions in nature occur between individual partners rather than species, and their outcomes determine fitness variation. By examining among-individual variation in interaction niches, we can bridge evolutionary and ecological perspectives to understand interaction biodiversity. This study investigates individual plant variation in frugivore assemblages worldwide, exploring how plant individuals "build" their interaction profiles with animal frugivores. The structure of networks composed of individuals was surprisingly similar to networks composed of species. Within populations, only a few plants played a key role in attracting a high diversity of frugivores, making them central to the overall network structure. Individuals actually interacted with a substantial diversity of partners, with individual niche "breadth" accounting for up to 70% of total interaction diversity, on average.

ecology↗

bioRxiv2022

Reciprocity and interaction effectiveness in generalised mutualisms among free-living species

Mutualistic interactions among free-living species generally involve weak links and highly asymmetric dependence among partners, yet our understanding of factors beyond their emergence is still limited. Using individual-based interactions of a super-generalist fleshy-fruited plant with its frugivore assemblage we estimate the Resource Provisioning Effectiveness (RPE) and Seed Dispersal Effectiveness (SDE) to assess the balance in the exchange of resources. Plants were highly dependent on a few super-generalist frugivore species, while these interacted with most individual plants, resulting in strong asymmetries in mutual dependence. Both RPE and SDE were mainly driven by interaction frequency. Despite highly asymmetric dependences, the strong reliance on quantity largely determined high reciprocity in rewards between partners (i.e., higher energy provided, more seedlings recruited), not obscured by minor variations in the quality of animal or plant service. We anticipate reciprocity will emerge in low-intimacy mutualisms where the mutualistic outcome largely relies upon interaction frequency.

ecology↗

bioRxiv2021

Global and regional ecological boundaries drive abrupt changes in avian frugivory interactions

Species interactions can propagate disturbances across space, though ecological and biogeographic boundaries may limit this spread. We tested whether large-scale ecological boundaries (ecoregions and biomes) and human disturbance gradients increase dissimilarity among ecological networks, while accounting for background spatial and elevational effects and differences in network sampling. We assessed network dissimilarity patterns over a broad spatial scale, using 196 quantitative avian frugivory networks (encompassing 1,496 plant and 1,003 bird species) distributed across 67 ecoregions and 11 biomes. Dissimilarity in species and interactions, but not in network structure, increased significantly across ecoregion and biome boundaries and along human disturbance gradients. Our findings suggest that ecological boundaries contribute to maintaining the worlds biodiversity of interactions and mitigating the propagation of disturbances at large spatial scales. One-Sentence SummaryEcoregions and biomes delineate the large-scale distribution of plant-frugivore interactions.

ecology↗

bioRxiv2020

Temporal and trophic partitioning promote coexistence between mesocarnivores in a Mediterranean landscape

O_LIThe partition of the ecological niche can enhance the coexistence of predators due to differences in how they exploit three main resources: food, space, and time, the latter being an axis that often remains unexplored. C_LIO_LIWe studied niche segregation in a Mediterranean mesocarnivore community composed by Vulpes vulpes, Genetta genetta, Meles meles and Herpestes ichneumon, addressing simultaneously different niche axes: the temporal, trophic and spatial axes. C_LIO_LIWe assessed temporal segregation between mesopredators and prey and between potential competitors, using camera trap data between 2018-2020 in a Mediterranean landscape in Southern Spain. We deployed camera traps in 35 stations in three sites with varying vegetation cover within Donana National Park. We further examined the spatial overlap in activity centers and trophic preferences between potential competitors using diet information from studies performed in the study area. C_LIO_LIWe found an overall temporal segregation between trophic generalist species, with species showing higher temporal overlap differing in their trophic preferences and/or showing limited spatial overlap. Furthermore, we observed an overall high overlap between the activity patterns of predators and their major prey in the area (the common genet vs small mammals and the red fox vs European rabbit). C_LIO_LIOur study suggests that coexistence of the different species that compose the mesocarnivore assemblage in Mediterranean landscapes can be facilitated by subtle differences along the three main niche axes, with temporal segregation being a most pronounced mechanism. Our findings reinforce the idea that the coexistence mechanisms underlying community structure are multidimensional. C_LI

ecology↗

bioRxiv2020

Assessing short- and long-term variations in diversity, timing, and body condition of migratory frugivorous birds

Under current global change context, climate change is driving substantial phenological mismatches between plant species and the organisms that rely on them. Given that frugivorous birds are fundamental for forest regeneration, and most of them are migrant species, identifying the effect of global change over them must be a priority. In this study we have analysed changes in the composition, morphometry, and physical condition in an avian community at long- (40 years) and short time (seasonal) spans. Our findings indicate a profound transformation at practically every level of analysis. In 40 years, the avian community shows a 66% and 13% decrease of the wintering and seed-disperser species, respectively. Seasonal abundance peaks were advanced in 13 out of 15 species. In addition, we have found a significant 1.5% increase in the morphometric measurements of certain species, supporting findings in previous studies, and also a remarkable general decrease of body condition. Our results point towards land use changes and climate change as the main causes. If this influence continues to rise, biodiversity will likely be irreversibly altered, damaging crucial ecosystem functions such as animal-mediated seed dispersal and forest regeneration in particular.

ecology↗

bioRxiv2020

Phenotypic and microsite plant individual variation determine the pollination network structure and its functional consequences

The biotic and abiotic context of individual plants in animal-pollinated plant populations may influence pollinator foraging behaviour and therefore how the pollen flow occurs. Thus, this variation among conspecifics within a given plant population can ultimately influence the plant reproductive success. Here we used a fine-scale, well characterized population of Halimium halimifolium in combination with exponential random graph models (ERGMs) to assess how the intrapopulation variation in intrinsic (i.e. phenotype and phenology) and extrinsic (i.e. microsite) plant attributes configures individual plant-pollinator networks and its functional consequences. We found that pollinator visitation patterns and the emerging network configuration were associated with both intrinsic and extrinsic plant attributes, such as the number of flowers, the flowering synchrony and the cover of intraspecific and interspecific neighbours. Both intrinsic and extrinsic plant attributes also affected the plant female reproductive success directly and indirectly - through its effects on the probability of conspecifics plants to share pollinators. Our study opens up new approaches to assess and predict the functional consequences of context-dependency in plant-pollinator interactions, especially under global change scenarios, where the ecological context of individual plants is likely to change.

ecology↗

bioRxiv2019

Seed-dispersal networks lose complexity in tropical forest fragments

Seed dispersal interactions involve key ecological processes in tropical forests that help to maintain ecosystem functioning. Yet this functionality may be threatened by increasing habitat loss, defaunation and fragmentation. However, generalist species, and their interactions, can benefit from the habitat change caused by human disturbance while more specialized interactions mostly disappear. Therefore changes in the structure of the local, within fragment, networks can be expected. Here we investigated how the structure of seed-dispersal networks changes along a gradient of increasing habitat fragmentation. We analysed 16 bird seed-dispersal assemblages from forest fragments of a biodiversity-rich ecosystem. We found significant species-, interaction- and network-area relationships, yet the later was determined by the number of species remaining in each community. The number of frugivorous bird and plant species, their interactions, and the number of links per species decreases as area is lost in the fragmented landscape. In contrast, network nestedness has a negative relationship with fragment area, suggesting an increasing generalization of the network structure in the gradient of fragmentation. Network specialization was not significantly affected by area, indicating that some network properties may be invariant to disturbance. Still, the local extinction of partner species, paralleled by a loss of interactions and specialist-specialist bird-plant seed dispersal associations suggests the functional homogenization of the system as area is lost. Our study provides empirical evidence for network-area relationships driven by the presence/absence of remnant species and the interactions they perform.\n\nRESUMOInteracoes de dispersao de sementes formam um processo ecologico chave em florestas tropicais onde colaboram na manutencao do funcionamento do ecossistema. Porem, esta funcionalidade pode estar ameacada pelo aumento na perda e fragmentacao do habitat. Enquanto especies generalistas e suas interacoes podem se beneficiar da mudanca de habitat causada por disturbios antropicos, interacoes envolvendo especies mais especialistas sao, na maioria, eliminadas. Desta forma, mudancas nas redes locais, dentro de fragmentos florestais, sao esperadas. Neste trabalho nos investigamos como a estrutura de redes de dispersao de sementes mudam em um gradiente de fragmentacao do habitat. Nos analisamos 16 comunidades de dispersao de sementes espacialmente explicitas e distribuidas em fragmentos florestais de um ecossistema rico em biodiversidade. Nos encontramos relacoes significativas entre a area do fragmento e especies, interacoes e estrutura das redes, sendo que o ultimo foi determinado pelo numero de especies remanescentes em cada comunidade. O numero de especies de aves frugivoras e plantas e as interacoes entre eles, bem como o numero de links por especie diminuiram significativamente conforme a area dos fragmentos e perdida. Por outro lado, o aninhamento da rede mostrou uma relacao negativa com a area do fragmento, sugerindo um aumento da generalizacao da estrutura das redes com a fragmentacao do habitat. No entanto, o grau de especializacao das redes nao foi afetado pela area, indicando que algumas propriedades de rede podem ser resistentes a perturbacao. Sendo assim, a extincao local de especies parceiras, conjuntamente com a perda das interacoes e associacoes planta-dispersor mais especializadas, sugere uma homogeneizacao do sistema conforme a area do fragmento e perdida. Nosso estudo fornece evidencias empiricas para as relacoes rede-area, sendo estas direcionadas pela presenca e/ou ausencia das especies remanescentes bem como das interacoes que estas realizam.

ecology↗