Ellen Andresen's research while affiliated with Universidad Nacional Autónoma de México and other places

Publications (82)

Article
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Landscape-scale deforestation poses a major threat to global biodiversity, not only because it causes habitat loss, but also because it can drive the degradation of remaining habitat. However, the multiple pathways by which deforestation directly and indirectly affects wildlife remains poorly understood, especially for elusive forest-dependent spec...
Article
Full-text available
Context. Biodiversity patterns depend on landscape structure, but the spatial scale at which such dependence is strongest (scale of effect, SoE) remains poorly understood, especially for elusive species such as arboreal tropical mammals. Objectives. To identify the SoE of arboreal mammals and assess whether it depends on the biological response and...
Article
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The conservation of tropical biodiversity not only depends on forest remnants, but also on anthropogenic land covers. Some shade crops are considered wildlife-friendly agroecosystems, but their conservation value is context- and taxon-dependent. Amphibians and reptiles have received less attention despite their high sensitivity to habitat disturban...
Article
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Introducción: Los escarabajos coprófagos realizan funciones importantes en los ecosistemas terrestres, pero las presiones antrópicas los afecta negativamente. Estos efectos están bien documentados en bosques Neotropicales de tierras bajas, pero se han estudiado poco en los bosques andinos. Objetivos: Evaluar cómo el cambio de uso del suelo afecta l...
Article
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Con la creciente pérdida y fragmentación de los ecosistemas naturales, entender cómo responden las especies a estos cambios nunca ha sido más urgente. Hoy existe consenso acerca del fuerte impacto negativo de la pérdida de hábitat sobre la biodiversidad. Sin embargo, el efecto de la fragmentación del hábitat ha sido muy debatido. En esta revisión,...
Preprint
Full-text available
Context Biodiversity patterns depend on landscape structure, but the spatial scale at which such dependence is strongest (scale of effect, SoE) remains poorly understood, especially for elusive species such as arboreal tropical mammals.Objectives To identify the SoE of arboreal mammals and assess whether it depends on the biological response and/or...
Article
Studies comparing different land covers clearly show that land-use change commonly affects animal communities and the ecological functions they play in ecosystems. However, we lack a good understanding of the effects that more subtle changes, those occurring within a land cover type, can have on ecological functions of animals, and if these are als...
Article
Understanding the factors and mechanisms shaping differences in species composition across space and time (β-diversity) in human-modified landscapes has key ecological and applied implications. This topic is, however, challenging because landscape disturbance can promote either decreases (biotic homogenization) or increases (biotic differentiation)...
Article
en Dung beetle activity causes many changes in the soil when they remove feces from the surface. In temperate grasslands and in greenhouse experiments, these changes have been found to positively affect established plants, but information about these effects under natural conditions in tropical forests is practically nonexistent. In a tropical rain...
Article
Land use change is a major threat to species’ persistence. Yet, the landscape attributes that shape populations remain poorly understood. Landscape-scale forest cover and matrix quality can favor population persistence, while forest fragmentation per se usually has weak effects on species. The impact of these spatial changes can, however, be influe...
Article
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Patch size is considered a major driver of species diversity in fragmented landscapes. Yet, assemblages of forest-dependent species, such as tropical arboreal mammals, can also depend on vegetation characteristics within the patch, i.e. patch quality. To test this, we assessed the influence of patch size and quality (measured through six attributes...
Article
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Tropical forest restoration initiatives are becoming more frequent worldwide in an effort to mitigate biodiversity loss and ecosystems degradation. However, there is little consensus on whether an active or a passive restoration strategy is more successful for recovering biodiversity because few studies make adequate comparisons. Furthermore, studi...
Article
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Peoples’ understanding and appreciation of wildlife are crucial for its conservation. Nevertheless, environmental education in many tropical countries is seldom incorporated into public-school curricula and wildlife topics are often underrepresented. In this research we aimed to (1) assess the effects of an environmental education intervention focu...
Article
Forest restoration may support recovery and conservation of biodiversity. However, the response of biodiversity to forest restoration is likely to vary depending on the restoration strategy used and taxa considered. Our goal was to assess the recovery of amphibians, a highly threatened biological group, in three cloud forests under different restor...
Article
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Context: Non-human primates are among the most threatened mammals on Earth. Although some species, such as howler monkeys, are thought to be resistant to initial phases of habitat disturbance, the lack of longitudinal studies prevents determining if this holds over time. Objectives: We assessed temporal changes in landscape structure in the Lacand...
Article
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Dung beetles are secondary seed dispersers, incidentally moving many of the seeds defecated by mammals vertically (seed burial) and/or horizontally as they process and relocate dung. Although several studies have quantified this ecological function of dung beetles, very few have followed seed fate until seedling establishment, and most of these hav...
Article
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Ecosystems largely depend, for both their functioning and their ecological integrity, on the ecological traits of the species that inhabit them. Non-human primates have a wide geographic distribution and play vital roles in ecosystem structure, function, and resilience. However, there is no comprehensive and updated compilation of information on ec...
Article
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El papel del venado cola blanca como dispersor endozoócoro de semillas se evaluó a través de la estimación del número de semillas y especies encontradas en las muestras fecales, y el análisis del efecto del paso por el tracto digestivo sobre el porcentaje y la velocidad de germinación en semillas de una especie focal (Acacia schaffneri). En total s...
Article
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Land-use change threatens a large number of tropical species (so-called ‘loser’ species), but a small subset of disturbance-adapted species may proliferate in human-modified landscapes (‘winner’ species). Identifying such loser and winner species is critically needed to improve conservation plans, but this task requires longitudinal studies that ar...
Article
Dung beetles relocate vertebrate feces under the soil surface, and this behavior has many ecological consequences. In tropical forests, for example, seeds defecated by mammals that are subsequently buried by dung beetles are less likely to suffer predation. While the effects of dung beetles on the fate of defecated seeds have been relatively well s...
Article
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Land-use change pushes biodiversity into human-modified landscapes, where native ecosystems are surrounded by anthropic land covers (ALCs). Yet, the ability of species to use these emerging covers remains poorly understood. We quantified the use of ALCs by primates worldwide, and analyzed species' attributes that predict such use. Most species use...
Article
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In tropical dry forests, a high interspecific variation in the strategies of fruiting phenology has been documented. Therefore, phenological responses may be mediated by influence of environmental variables, functional plant attributes or phylogenetic inertia. During 2 years, we recorded the fruiting phenology of 151 species belonging to 5 differen...
Article
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Primates are important seed dispersers in natural ecosystems and agro-ecosystems, but the latter scenario remains under-studied. The degree to which primates favour plant regeneration greatly depends on post-dispersal processes. The main objective of this study was to compare patterns of seed/seedling fate and seedling recruitment in two habitats o...
Article
Full-text available
Primates are important seed dispersers in natural ecosystems and agro-ecosystems, but the latter scenario remains under-studied. The degree to which primates favour plant regeneration greatly depends on post-dispersal processes. The main objective of this study was to compare patterns of seed/seedling fate and seedling recruitment in two habitats o...
Article
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There is growing interest in evaluating the impact that management intensity of agroecosystems has on animal communities and their ecological functions. Dung beetles are a highly used focal taxon for assessing the effects of anthropogenic disturbances and management practices on biodiversity. In the Lacandona rainforest region in southern Mexico, w...
Article
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We identified some interactions between fruits/seeds of Heteroflorum sclerocarpum (Leguminosae) and terrestrial mammals of a Mexican tropical dry forest. The mammals that consume the fruits and seeds of this species were detected using camera traps, and by observations in captivity and field, it was determined how mammals manipulate these structure...
Article
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Primate seed dispersal plays crucial roles in many ecological processes at various levels of biological organization: from plant population genetics and demography, to community assembly, and ecosystem function. Although research on primate seed dispersal has advanced significantly in the last 20-30 years, many aspects are still poorly understood....
Article
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Dung beetles (Scarabaeinae) are important insects in many terrestrial ecosystems due to their ecological functions, which are a consequence of their dung-burying behavior. This insect group is particularly abundant in tropical forests (TF). Yet, their ecological functions have been studied more extensively in humid TF and little information is avai...
Article
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Interactions between fleshy fruited plants and frugivores are crucial for the structuring and functioning of biotic communities, particularly in tropical forests where both groups are diverse and play different roles in network organization. However, it remains poorly understood how different groups of frugivore species and fruit traits contribute...
Article
Tropical forests are undergoing a biodiversity crisis including defaunation processes. Structure and function of biotic communities in disturbed ecosystems can be assessed with network analyses of interspecific interactions. In a disturbed tropical forest we studied the network of interactions between fruiting plants and three groups of frugivorous...
Chapter
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Most of the Earth's terrestrial biodiversity is found in tropical forests, a fact that fascinates us today as it did the early naturalists of past centuries. It is in this biome where a tremendously high number of coexisting species weave themselves into the most complex web of life, linked together through biotic interactions. These interactions a...
Article
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Primary seed dispersal of many rain-forest seeds occurs through defecation by mammals. Dung beetles are attracted to the defecations and through their dung-processing behaviour these insects change the initial pattern of seed deposition. Final seed deposition patterns, i.e. where and how seeds are deposited after dung beetle activity has taken plac...
Article
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The recovery of vegetation cover is a process that has important implications for the conservation of biodiversity and ecosystem services. Generally, the recovery of vegetation cover is documented over large areas using remote sensing, and it is often assumed that ecosystem properties and processes recover along with remotely sensed canopy cover. H...
Article
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We document the first record of Craugastor psephosypharus (Craugastoridae) for Mexico. In October 2014, we collected 2 individuals of this species and observed another 8 specimens in a tropical moist forest fragment in the Lacandona region, southeastern Mexico. We found the frogs during daytime in the rainy season, in the vicinity of a small karst...
Article
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The frequency and intensity of hurricanes are likely to increase in the Caribbean due to climate change, potentially threatening the long-term conservation of biodiversity in vulnerable island ecosystems. The effects of hurricanes were assessed for the understory forest birds of Cozumel Island during the first and second year after two consecutive...
Article
Dung beetles are extensively used as a focal taxon in tropical forests. Yet, information for most of their ecological functions comes from other systems. We present results from a field experiment in a tropical rain forest showing that dung beetle activity increases foliar phosphorus concentration in seedlings of the tree Brosimum lactescens. Our r...
Article
Primates are important seed dispersers in tropical forests, but they are being lost due to forest fragmentation. We compared post-dispersal seed fate and seedling density for the tree Dialium guianense , in forest fragments in which its main seed disperser, the mantled howler monkey ( Alouatta palliata ) is present, and in fragments in which it is...
Article
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Ecological communities are dynamic collections whose composition and structure change over time, making up complex interspecific interaction networks. Mutualistic plant–animal networks can be approached through complex network analysis; these networks are characterized by a nested structure consisting of a core of generalist species, which endows t...
Data
Image of Non-metric multidimensional scaling (NMDS) ordinations for the composition of frugivorous bird species at the network core (a) and the network periphery (b) Non-metric multidimensional scaling (NMDS) ordinations for the composition of frugivorous bird species at the network core (a) and the network periphery (b). To carry out the analysis...
Data
Species list and migratory status Species list of frugivorous birds and plants they interact with. ID contains the codes depicted at the graphs. Birds were classified according to their migratory status (resident and migrant).
Data
Raw data: Quantitative matrix of plant-bird interactions networks
Data
Relation of fruit availability (fruit richness and abundance) and bird migration with parameters of bird-plant networks Relation of fruit availability (fruit richness and abundance) and bird migration with parameters of bird-plant networks at CICOLMA. Significant relations were in bold (P ≤ 0.05).
Data
Raw data: Proportion of migratory birds present in each temporal network and fruit availability
Data
Raw data: List of species in the core and periphery of each temporal networks
Article
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Context Identifying the drivers shaping biological assemblages in fragmented tropical landscapes is critical for designing effective conservation strategies. It is still unclear, however, whether tropical biodiversity is more strongly affected by forest loss, by its spatial configuration or by matrix composition across different spatial scales. Ob...
Chapter
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Primate seed dispersal has been increasingly recognized as having a potentially profound impact on tropical forest regeneration and plant species composition. Confirming and quantifying this impact, however, has proven to be an important challenge. We review the literature on seed dispersal by howler monkeys (Alouatta spp.) throughout their geograp...
Article
Dung beetles are known to perform important ecological functions, such as secondary seed dispersal of vertebrate-defecated seeds. We found that dung beetles also move buried seeds upwards, with positive consequences for seedling establishment. In the Lacandon rain forest of southern Mexico we conducted field experiments to address three questions:...
Article
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Recent evidence has shown that primates worldwide use agroecosystems as temporary or permanent habitats. Detailed information on how these primates are using these systems is scant, and yet their role as seed dispersers is often implied. The main objective of this study was to compare the activity, foraging patterns and seed dispersal role of black...
Presentation
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Recent research in tropical agroecosystems suggests that the impact of agriculture on biodiversity may depend on the particular system in question. In particular, an agricultural matrix with a complex vegetation structure could promote the movement of organisms among landscape components. Such connectivity could, in turn, help maintain key ecologic...
Article
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Animals' responses to potentially threatening factors can provide important information for their conservation. Group size and human presence are potentially threatening factors to primates inhabiting small reserves used for recreation. We tested these hypotheses by evaluating behavioral and physiological responses in two groups of mantled howler m...
Article
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Although there is increasing interest in the effects of habitat disturbance on community attributes and the potential consequences for ecosystem functioning, objective approaches linking biodiversity loss to functional loss are uncommon. The objectives of this study were to implement simultaneous assessment of community attributes (richness, abunda...
Data
Results of the analyses with generalized linear models (GLMs) showing the effects of land use systems on community attributes and ecological functions. (DOCX)
Article
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By linking phenological patterns not only to climatic factors but also to plant functional traits we may gain a better understanding of plant community function and assembly. While phenological patterns and dispersal syndromes have been well studied for temperate forests in boreal latitudes, as well as tropical forests, little information is availa...
Article
Seeds of many plant species are secondarily dispersed by dung beetles, but the outcome of this interaction is highly context-specific. Little is known about how certain anthropogenic disturbances affect this plant-animal interaction. The aims of this study were to assess the effect of dung type on secondary dispersal by dung beetles in a forest fra...
Article
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The disappearance of frugivorous primates in fragmented forests can potentially lower the rates of seed dispersal and recruitment of endozoochorous tree species, thus altering plant community structure. We quantified seedling density for 7 tree species that are common in the feces of mantled howlers (Alouatta palliata) in 6 rain forest fragments in...
Article
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In rain forests the fate of seeds defecated by mammals is often affected by dung beetles, but these effects can vary with mammal species. In a Colombian forest, differences in Scarabaeinae assemblages attracted to spider monkey (Ateles hybridus) and howler monkey (Alouatta seniculus) defecations were assessed. In total, 791 beetles of 35 species we...
Article
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The purpose of this study was to assess farmers' attitudes, as well as perceptions and knowledge that shape those attitudes, toward the ecological role of vertebrates inhabiting shaded-coffee farms. We also aimed to determine whether differences existed among two groups of farmers: one that had attended environmental education workshops, and one th...
Article
1. Roads may affect wildlife populations through habitat loss and disturbances, as they create an abrupt linear edge, increasing the proportion of edge exposed to a different habitat. Three types of edge effects have been recognized: abiotic, direct biotic, and indirect biotic. 2. We explored the direct biotic edge effects of 3- to 4-m wide roads,...