RESUMO
Climate change is forcing the redistribution of life on Earth at an unprecedented velocity1,2. Migratory birds are thought to help plants to track climate change through long-distance seed dispersal3,4. However, seeds may be consistently dispersed towards cooler or warmer latitudes depending on whether the fruiting period of a plant species coincides with northward or southward migrations. Here we assess the potential of plant communities to keep pace with climate change through long-distance seed dispersal by migratory birds. To do so, we combine phenological and migration information with data on 949 seed-dispersal interactions between 46 bird and 81 plant species from 13 woodland communities across Europe. Most of the plant species (86%) in these communities are dispersed by birds migrating south, whereas only 35% are dispersed by birds migrating north; the latter subset is phylogenetically clustered in lineages that have fruiting periods that overlap with the spring migration. Moreover, the majority of this critical dispersal service northwards is provided by only a few Palaearctic migrant species. The potential of migratory birds to assist a small, non-random sample of plants to track climate change latitudinally is expected to strongly influence the formation of novel plant communities, and thus affect their ecosystem functions and community assembly at higher trophic levels.
Assuntos
Aclimatação , Migração Animal , Aves/fisiologia , Temperatura Baixa , Aquecimento Global , Plantas , Dispersão de Sementes , Animais , Ecossistema , Europa (Continente) , Voo Animal , Mar MediterrâneoRESUMO
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.
Assuntos
Ecossistema , Dispersão de Sementes , Florestas , Sementes , Frutas , ÁrvoresRESUMO
Data on SARS-CoV-2 infection in wildlife species is limited. The high prevalences found in mustelid species such as free-ranging American minks (Neovison vison) and domestic ferrets (Mustela putorius furo) justify the study of this virus in the closely related autochthonous free-ranging European polecat (Mustela putorius). We analysed lung samples from 48 roadkilled polecats collected when the human infection reached its highest levels in Spain (2020-2021). We did not detect infections by SARS-CoV-2; however, surveillance in wild carnivores and particularly in mustelids is still warranted, due to their susceptibility to this virus.
RESUMO
Apex predators play key roles in food webs and their recovery can trigger trophic cascades in some ecosystems. Intra-guild competition can reduce the abundances of smaller predators and perceived predation risk can alter their foraging behaviour thereby limiting seed dispersal by frugivorous carnivores. However, little is known about how plant-frugivore mutualisms could be disturbed in the presence of larger predators. We evaluated the top-down effect of the regional superpredator, the Iberian lynx Lynx pardinus, on the number of visits and fruits consumed by medium-sized frugivorous carnivores, as well as the foraging behaviour of identified individuals, by examining the consumption likelihood and the foraging time. We carried out a field experiment in which we placed Iberian pear Pyrus bourgaeana fruits beneath fruiting trees and monitored pear removal by frugivorous carnivores, both inside and outside lynx ranges. Using camera traps, we recorded the presence of the red fox Vulpes vulpes, the Eurasian badger Meles meles and the stone marten Martes foina, as well as the number of fruits they consumed and their time spent foraging. Red fox was the most frequent fruit consumer carnivore. We found there were fewer visits and less fruit consumed by foxes inside lynx ranges, but lynx presence did not seem to affect badgers. We did not observe any stone marten visits inside lynx territories. The foraging behaviour of red foxes was also altered inside lynx ranges whereby foxes were less efficient, consuming less fruit per unit of time and having shorter visits. Local availability of fruit resources, forest coverage and individual personality also were important variables to understand visitation and foraging in a landscape of fear. Our results show a potential trophic cascade from apex predators to primary producers. The presence of lynx can reduce frugivorous carnivore numbers and induce shifts in their feeding behaviour that may modify the seed dispersal patterns with likely consequences for the demography of many fleshy-fruited plant species. We conclude that knowledge of the ecological interactions making up trophic webs is an asset to design effective conservation strategies, particularly in rewilding programs.
Los depredadores ápice juegan papeles clave en las cadenas tróficas y su recuperación puede dar lugar a cascadas tróficas en algunos ecosistemas. La competición intra-gremial puede reducir las abundancias de los depredadores más pequeños y el riesgo de depredación percibido puede alterar su comportamiento de forrajeo, llegando a limitar la dispersión de semillas de los carnívoros frugívoros. Sin embargo, se sabe poco sobre cómo un mutualismo planta-animal podría ser alterado en presencia de grandes depredadores. Aquí evaluamos los efectos en cascada del superdepredador regional, el lince ibérico Lynx pardinus, sobre el número de visitas y frutos consumidos por los carnívoros frugívoros de mediano tamaño, a la vez que el comportamiento de alimentación de individuos identificados, examinando la probabilidad de consumo y el tiempo de forrajeo. Llevamos a cabo un experimento en el que colocamos frutos de piruétano Iberian pear bajo árboles productores y monitoreamos la remoción de peras por los carnívoros frugívoros, tanto dentro como fuera de territorios de lince. Mediante el uso de cámaras trampa, registramos la presencia de zorro rojo Vulpes vulpes, tejón europeo Meles meles y garduña Martes foina, además del número de frutos que consumieron y el tiempo que emplearon forrajeando. El zorro rojo fue el carnívoro consumidor de frutos más frecuente. Encontramos que había menos visitas y un menor consumo de frutos por zorros dentro de los territorios del lince, pero la presencia de lince no pareció afectar a los tejones. No registramos ninguna visita de garduña dentro de los territorios de los linces. El comportamiento de forrajeo de los zorros rojos fue también alterado dentro del rango de distribución del lince, donde los zorros fueron menos eficientes, consumieron menos frutos por unidad de tiempo y realizaron visitas más cortas. La disponibilidad local de frutos, la cobertura forestal y la personalidad individual también fueron variables importantes para entender los patrones de visita y forrajeo en un paisaje del miedo. Nuestros resultados muestran una cascada trófica potencial desde un superdepredador hasta los productores primarios. La presencia de lince puede reducir la abundancia de carnívoros frugívoros e inducir cambios en sus patrones de alimentación que pueden modificar los patrones de dispersión de semillas con probables consecuencias para la demografía de muchas especies de plantas de fruto carnoso. Concluimos que el conocimiento de las interacciones ecológicas que componen las redes tróficas es esencial para diseñar estrategias de conservación eficaces, especialmente en programas de reintroducción.
Assuntos
Carnívoros/fisiologia , Comportamento Alimentar/fisiologia , Cadeia Alimentar , Frutas/fisiologia , Comportamento Predatório/fisiologia , Animais , Ecossistema , Raposas/fisiologia , Lynx/fisiologia , Mustelidae/fisiologia , SimbioseRESUMO
The Seed Dispersal Syndrome Hypothesis (SDSH) posits that fruit traits predict the main dispersers interacting with plant species. Mammalian dispersers, relying heavily on olfactory cues, are expected to select dull-colored, scented, and larger fruits compared to birds. However, challenges like overabundant seed predators and context-dependency of frugivore-plant interactions complicate SDSH expectations. We studied the Iberian pear, Pyrus bourgaeana, an expected mammal-dispersed tree based on its fruit traits. Extensive camera-trapping data (over 35,000 records) from several tree populations and years revealed visits from seven frugivore groups, with ungulate fruit predators (59-97%) and carnivore seed dispersers (1-20%) most frequent, while birds, lagomorphs, and rodents were infrequent (0-10%). Red deer and wild boar were also the main fruit removers in all sites and years but acted as fruit and seed predators, and thus likely exert conflicting selection pressures to those exerted by seed dispersers. Although, as predicted by the SDSH, most Iberian pear fruits were consumed by large and medium-sized mammals, the traits of Iberian pear fruits likely reflect selection pressures from dispersal vectors in past times. Our results do not challenge the SDHS but do reveal the importance of considering frugivore functional roles for its adequate evaluation.
Assuntos
Cervos , Lagomorpha , Pyrus , Dispersão de Sementes , Animais , Frutas , SementesRESUMO
Mesopredators abundance is often limited by top-order predators and also by key food resources. However, the contribution of these bidirectional forces to structure carnivore community is still unclear. Here, we studied how the presence and absence of an apex predator which is currently recovering its former distribution range, the Iberian lynx (Lynx pardinus), determined the absolute abundance and fine-scale spatiotemporal avoidance mechanisms of two sympatric mesocarnivores (stone marten Martes foina and common genet Genetta genetta) with different dietary plasticity. We hypothesized that the lynx causes a mesopredator suppression and subordinate predators develop segregation strategies in respect to their trophic niche breadth. We placed 120 camera-traps in Southern Spain for 8 months in two consecutive years to estimate mesocarnivore abundances by using SCR Bayesian models, prey availability and assess spatio-temporal patterns. We found that the lynx reduced mesocarnivore abundance up to 10 times. Stone marten, a mesopredator with a broad food resources spectrum, showed a total spatial exclusion with the apex predator. Meanwhile, fine-scale avoidance mechanisms allowed the genet to persist in low density inside lynx territories, probably taking advantage of high availability of its preferred prey. Thus, the strength of these top-down and bottom-up effects was rather species-specific. Given the recent recovery of large carnivore populations worldwide, variation in suppression levels on different mesopredator species could modify ecosystem functions provided by the carnivore community in contrasting ways.
Assuntos
Carnívoros , Lynx , Mustelidae , Animais , Ecossistema , Cadeia Alimentar , Viverridae , Teorema de Bayes , Dinâmica Populacional , Comportamento PredatórioRESUMO
Introducción: existe un debate en la actualidad acerca de si la artritis reactiva post-estreptocócica es una entidad separada o una condición en el espectro de la fiebre reumática aguda. Objetivo: revisar la literatura existente sobre el tema artritis reactiva post-estreptocócica. Desarrollo : se realizó una búsqueda bibliográfica en Medline, Pubmed, Scielo y Dialnet, buscando como palabras clave: artritis y artritis reactiva post-estreptocócica. Además de la búsqueda computadorizada se realizó una búsqueda manual. Dichas bases de datos recogen las publicaciones más importantes en el campo científico de la medicina. La búsqueda se realizó en abril del 2018, y comprendió desde el año 1989 hasta la actualidad. Utilizamos el programa Reference Manager, versión 12, para crear una base de datos con las publicaciones, categorizarlas y filtrarlas de acuerdo a su relevancia para nuestro estudio. Se recabaron un total de 45 documentos en total, de los cuales fueron descartados unos 30, debido a su nivel de generalización y escasa especificidad en el tema abordado. Conclusiones: los signos clásicos de tumefacción, eritema, calor y dolor están presentes, siendo el dolor el más importante, está presente en reposo y aumenta con los movimientos. Como en la FR, la artritis postestreptocócica es una artritis reactiva caracterizada por una infección faríngeaestreptocócica, un intervalo libre y una posterior inflamación aséptica en una o más articulaciones(AU)
Introduction: there is currently debate about whether post-streptococcal reactive arthritis is a separate entity or condition in the spectrum of acute rheumatic fever. Objective: to review the existing literature on the topic post-streptococcal reactive arthritis. Development: a bibliographic search was carried out in Medline, Pubmed, Scielo and Dialnet, searching as keywords: arthritis and post-streptococcal reactive arthritis. In addition to the computerized search, a manual search was carried out. These databases collect the most important publications in the scientific field of medicine. The search was conducted in April 2018, and ran from 1989 to the present. We use the Reference Manager program, version 12, to create a database with publications, categorize them and filter them according to their relevance to our study. A total of 45 documents were collected, of which about 30 were discarded, due to their level of generalization and lack of specificity in the topic addressed. Conclusions: the classic signs of swelling, erythema, heat and pain are present, with pain being the most important, it is present at rest and increases with movements. As in RF, post-streptococcal arthritis is a reactive arthritis characterized by a pharyngeal-streptococcal infection, a free interval and subsequent aseptic inflammation in one or more joints(AU)
Assuntos
Humanos , Febre Reumática , Infecções Estreptocócicas , Artrite ReativaRESUMO
La enfermedad de Behçet se considera una entidad multisistémica identificada por aftas orales y genitales, lesiones cutáneas, artritis, manifestaciones gastrointestinales, neurológicas y oculares, pertenece al conjunto de afecciones consideradas autoinmunes en la que se puede afectar a cualquier vaso sanguíneo del organismo, para su diagnóstico se sugieren un grupo de criterios que examina regularmente un comité internacional de especialistas en las que deben incluir aftas periódicas en boca y genitales acompañados de hipopion y uveítis, su tratamiento en la actualidad se dirige a disminuir la actividad del sistema inmune y tiene como objetivo reducir los síntomas y prevenir las complicaciones(AU)
Behçet's disease is considered a multisystemic entity identified by oral and genital thrush, skin lesions, arthritis, gastrointestinal, neurological and ocular manifestations, belongs to the set of conditions considered autoimmune in which any blood vessel of the organism can be affected, for its Diagnosis is suggested a group of criteria that regularly examines an international committee of specialists in which they must include periodic canker sores in the mouth and genitals accompanied by hypopion and uveitis, their treatment is currently aimed at decreasing the activity of the immune system and aims reduce symptoms and prevent complications(AU)