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1.
Ecol Evol ; 14(5): e11420, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38774139

RESUMEN

Climate change majorly impacts biodiversity in diverse regions across the world, including South Asia, a megadiverse area with heterogeneous climatic and vegetation regions. However, climate impacts on bats in this region are not well-studied, and it is unclear whether climate effects will follow patterns predicted in other regions. We address this by assessing projected near-future changes in climatically suitable areas for 110 bat species from South Asia. We used ensemble ecological niche modelling with four algorithms (random forests, artificial neural networks, multivariate adaptive regression splines and maximum entropy) to define climatically suitable areas under current conditions (1970-2000). We then extrapolated near future (2041-2060) suitable areas under four projected scenarios (combining two global climate models and two shared socioeconomic pathways, SSP2: middle-of-the-road and SSP5: fossil-fuelled development). Projected future changes in suitable areas varied across species, with most species predicted to retain most of the current area or lose small amounts. When shifts occurred due to projected climate change, new areas were generally northward of current suitable areas. Suitability hotspots, defined as regions suitable for >30% of species, were generally predicted to become smaller and more fragmented. Overall, climate change in the near future may not lead to dramatic shifts in the distribution of bat species in South Asia, but local hotspots of biodiversity may be lost. Our results offer insight into climate change effects in less studied areas and can inform conservation planning, motivating reappraisals of conservation priorities and strategies for bats in South Asia.

2.
Ecol Evol ; 14(2): e10910, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38304266

RESUMEN

Asynchrony in population abundance can buffer the effects of environmental change leading to greater community and ecosystem stability. Both environmental (abiotic) drivers and species functional (biotic) traits can influence population dynamics leading to asynchrony. However, empirical evidence linking dissimilarity in species traits to abundance asynchrony is limited, especially for understudied taxa such as insects. To fill this knowledge gap, we explored the relationship between pairwise species trait dissimilarity and asynchrony in interannual abundance change between pairs of species for 422 moth, butterfly, and bumblebee species in Great Britain. We also explored patterns differentiating traits that we assumed to capture 'sensitivity to environmental variables' (such as body mass), and traits that may reflect 'diversity in exposure' to environmental conditions and lead to niche partitioning (for example, habitat uses, and intra-annual emergence periods). As expected, species trait dissimilarity calculated overall and for many individual traits representing response and exposure was positively correlated with asynchrony in all three insect groups. We found that 'exposure' traits, especially those relating to the phenology of species, had the strongest relationship with abundance asynchrony from all tested traits. Positive relationships were not simply due to shared evolutionary history leading to similar life-history strategies: detected effects remained significant for most traits after accounting for phylogenetic relationships within models. Our results provide empirical support that dissimilarity in traits linked to species exposure and sensitivity to the environment could be important for temporal dissimilarity in insect abundance. Hence, we suggest that general trait diversity, but especially diversity in 'exposure' traits, could play a significant role in the resilience of insect communities to short-term environmental perturbations through driving asynchrony between species abundances.

3.
Glob Chang Biol ; 30(1): e17119, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38273572

RESUMEN

Comparative extinction risk analysis-which predicts species extinction risk from correlation with traits or geographical characteristics-has gained research attention as a promising tool to support extinction risk assessment in the IUCN Red List of Threatened Species. However, its uptake has been very limited so far, possibly because existing models only predict a species' Red List category, without indicating which Red List criteria may be triggered. This prevents such approaches to be integrated into Red List assessments. We overcome this implementation gap by developing models that predict the probability of species meeting individual Red List criteria. Using data on the world's birds, we evaluated the predictive performance of our criterion-specific models and compared it with the typical criterion-blind modelling approach. We compiled data on biological traits (e.g. range size, clutch size) and external drivers (e.g. change in canopy cover) often associated with extinction risk. For each specific criterion, we modelled the relationship between extinction risk predictors and species' Red List category under that criterion using ordinal regression models. We found criterion-specific models were better at identifying threatened species compared to a criterion-blind model (higher sensitivity), but less good at identifying not threatened species (lower specificity). As expected, different covariates were important for predicting extinction risk under different criteria. Change in annual temperature was important for criteria related to population trends, while high forest dependency was important for criteria related to restricted area of occupancy or small population size. Our criteria-specific method can support Red List assessors by producing outputs that identify species likely to meet specific criteria, and which are the most important predictors. These species can then be prioritised for re-evaluation. We expect this new approach to increase the uptake of extinction risk models in Red List assessments, bridging a long-standing research-implementation gap.


Asunto(s)
Conservación de los Recursos Naturales , Especies en Peligro de Extinción , Animales , Conservación de los Recursos Naturales/métodos , Extinción Biológica , Bosques , Medición de Riesgo , Biodiversidad
4.
PLoS One ; 18(12): e0290836, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38060478

RESUMEN

To protect biodiversity we must understand its structure and composition including the bacteria and microparasites associated with wildlife, which may pose risks to human health. However, acquiring this knowledge often presents challenges, particularly in areas of high biodiversity where there are many undescribed and poorly studied species and funding resources can be limited. A solution to fill this knowledge gap is sampling roadkill (animals that die on roads as a result of collisions with circulating vehicles). These specimens can help characterize local wildlife and their associated parasites with fewer ethical and logistical challenges compared to traditional specimen collection. Here we test this approach by analyzing 817 tissue samples obtained from 590 roadkill vertebrate specimens (Amphibia, Reptilia, Aves and Mammalia) collected in roads within the Tropical Andes of Ecuador. First, we tested if the quantity and quality of recovered DNA varied across roadkill specimens collected at different times since death, exploring if decomposition affected the potential to identify vertebrate species and associated microorganisms. Second, we compared DNA stability across taxa and tissues to identify potential limitations and offer recommendations for future work. Finally, we illustrate how these samples can aid in taxonomic identification and parasite detection. Our study shows that sampling roadkill can help study biodiversity. DNA was recovered and amplified (allowing species identification and parasite detection) from roadkill even 120 hours after death, although risk of degradation increased overtime. DNA was extracted from all vertebrate classes but in smaller quantities and with lower quality from amphibians. We recommend sampling liver if possible as it produced the highest amounts of DNA (muscle produced the lowest). Additional testing of this approach in areas with different environmental and traffic conditions is needed, but our results show that sampling roadkill specimens can help detect and potentially monitor biodiversity and could be a valuable approach to create biobanks and preserve genetic data.


Asunto(s)
Animales Salvajes , Bancos de Muestras Biológicas , Animales , Humanos , Vertebrados , Mamíferos , Anfibios , ADN
5.
Conserv Biol ; 37(6): e14139, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37394972

RESUMEN

Despite being central to the implementation of conservation policies, the usefulness of the International Union for Conservation of Nature (IUCN) Red List of Threatened Species is hampered by the 14% of species classified as data-deficient (DD) because information to evaluate these species' extinction risk was lacking when they were last assessed or because assessors did not appropriately account for uncertainty. Robust methods are needed to identify which DD species are more likely to be reclassified in one of the data-sufficient IUCN Red List categories. We devised a reproducible method to help red-list assessors prioritize reassessment of DD species and tested it with 6887 DD species of mammals, reptiles, amphibians, fishes, and Odonata (dragonflies and damselflies). For each DD species in these groups, we calculated its probability of being classified in a data-sufficient category if reassessed today from covariates measuring available knowledge (e.g., number of occurrence records or published articles available), knowledge proxies (e.g., remoteness of the range), and species characteristics (e.g., nocturnality); calculated change in such probability since last assessment from the increase in available knowledge (e.g., new occurrence records); and determined whether the species might qualify as threatened based on recent rate of habitat loss determined from global land-cover maps. We identified 1907 species with a probability of being reassessed in a data-sufficient category of >0.5; 624 species for which this probability increased by >0.25 since last assessment; and 77 species that could be reassessed as near threatened or threatened based on habitat loss. Combining these 3 elements, our results provided a list of species likely to be data-sufficient such that the comprehensiveness and representativeness of the IUCN Red List can be improved.


Priorización de la reevaluación de las especies con datos deficientes en la Lista Roja de la UICN Resumen No obstante que es fundamental para la implementación de políticas de conservación, la utilidad de la Lista Roja de Especies Amenazadas de la Unión Internacional para la Conservación de la Naturaleza (UICN) está limitada por el 14% de especies clasificadas con datos deficientes (DD) debido a que la información para evaluar el riesgo de extinción de estas especies no existía cuando fueron evaluadas la última vez o porque los evaluadores no consideraron la incertidumbre apropiadamente. Se requieren métodos robustos para identificar las especies DD con mayor probabilidad de ser reclasificadas en alguna de las categorías en la Lista Roja UICN con datos suficientes. Diseñamos un método reproducible para ayudar a que los evaluadores de la lista roja prioricen la reevaluación de especies DD y lo probamos con 6,887 especies DD de mamíferos, reptiles, anfibios, peces y Odonata (libélulas y caballitos del diablo). Para cada una de las especies DD en estos grupos, calculamos la probabilidad de ser clasificadas en una categoría con datos suficientes si fuera reevaluada hoy a partir de covariables que miden el conocimiento disponible (e.g., número de registros de ocurrencia o artículos publicados disponibles), sustitutos de conocimiento (e.g., extensión del rango de distribución) y características de la especie ((e.g., nocturnidad); calculamos el cambio en tal probabilidad desde la última reevaluación a partir del incremento en el conocimiento disponible (e.g., registros de ocurrencia nuevos); y determinamos si las especies podrían calificar como amenazadas con base en pérdidas de hábitat recientes a partir de mapas globales de cobertura de suelo recientes. Identificamos 1,907 especies con una probabilidad >0.5 de ser reclasificados en una categoría con datos suficientes; 624 especies cuya probabilidad aumentó en >0.25 desde la última evaluación, y 77 especies que podrían ser reclasificadas como casi en peligro con base en la pérdida de hábitat. Combinando estos 3 elementos, nuestros resultados proporcionaron una lista de especies probablemente con datos suficientes de tal modo que la exhaustividad y la representatividad de la Lista Roja de la UICN pueden ser mejoradas.


Asunto(s)
Conservación de los Recursos Naturales , Odonata , Animales , Especies en Peligro de Extinción , Extinción Biológica , Ecosistema , Mamíferos , Peces , Biodiversidad
6.
Ecol Evol ; 13(3): e9916, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36993143

RESUMEN

Ecuador has both high richness and high endemism, which are increasingly threatened by anthropic pressures, including roads. Research evaluating the effects of roads remains scarce, making it difficult to develop mitigation plans. Here, we present the first national assessment of wildlife mortality on roads that allow us to (1) estimate roadkill rates per species, (2) identify affected species and areas, and (3) reveal knowledge gaps. We bring together data from systematic surveys and citizen science efforts to present a dataset with 5010 wildlife roadkill records from 392 species, and we also provide 333 standardized corrected roadkill rates calculated on 242 species. Systematic surveys were reported by ten studies from five Ecuadorian provinces, revealing 242 species with corrected roadkill rates ranging from 0.03 to 171.72 ind./km/year. The highest rates were for the yellow warbler Setophaga petechia in Galapagos (171.72 ind./km/year), the cane toad Rhinella marina in Manabi (110.70 ind./km/year), and the Galapagos lava lizard Microlophus albemarlensis (47.17 ind./km/year). Citizen science and other nonsystematic monitoring provided 1705 roadkill records representing all 24 provinces in Ecuador and 262 identified species. The common opossum Didelphis marsupialis, the Andean white-eared opossum Didelphis pernigra, and the yellow warbler Setophaga petechia were more commonly reported (250, 104, and 81 individuals, respectively). Across all sources, we found 15 species listed as "Threatened" and six as "Data Deficient" by the IUCN. We recommend stronger research efforts in areas where the mortality of endemic or threatened species could be critical for populations, such as in Galapagos. This first country-wide assessment of wildlife mortality on Ecuadorian roads represents contributions from academia, members of the public, and government, underlining the value of wider engagement and collaboration. We hope these findings and the compiled dataset will guide sensible driving and sustainable planning of infrastructure in Ecuador and, ultimately, contribute to reduce wildlife mortality on roads.


Ecuador tiene gran riqueza y alto endemismo de especies, mismas que están amenazadas por presiones antrópicas como las carreteras. Sin embargo, la investigación en este campo es escasa, dificultando el desarrollo de planes de mitigación. Presentamos la primera evaluación nacional de mortalidad de fauna silvestre en carreteras que nos permite 1) estimar tasas de atropellamiento por especies, 2) identificar especies y áreas afectadas, y 3) revelar vacíos de información. Compilamos datos de estudios sistemáticos y esfuerzos de ciencia ciudadana en Ecuador para presentar una base de datos que comprende 5010 registros de atropellamientos correspondientes a 392 especies, también proveemos 333 tasas de atropellamiento estandarizadas para 242 especies. Monitoreos sistemáticos fueron reportados por diez estudios de cinco provincias del Ecuador, revelando 242 especies con una tasa de mortalidad que varía entre 0.03 y 171.72 ind./km/año. Las tasas de atropellamiento más altas correspondieron a la reinita amarilla Setophaga petechia en Galápagos (171.72 ind./km/año), el sapo de la caña Rhinella marina in Manabí (110.70 ind./km/año), y la lagartija de lava de Galápagos Microlophus albemarlensis (47.17 ind./km/año). La ciencia ciudadana y monitoreos no sistemáticos proporcionaron 1705 registros representando a las 24 provincias de Ecuador y a 262 especies identificadas. La zarigüeya común Didelphis marsupialis, la zarigüeya orejiblanca andina Didelphis pernigra y la reinita amarilla Setophaga petechia fueron las más reportadas (250, 104 y 81 individuos respectivamente). Considerando todas las fuentes de datos encontramos 15 especies clasificadas como amenazadas y seis como datos insuficientes por la UICN. Recomendamos mayores esfuerzos de investigación en áreas donde la mortalidad de especies endémicas o amenazadas puede ser crítica para las poblaciones, como en Galápagos. Esta primera evaluación de mortalidad silvestre en carreteras ecuatorianas representa contribuciones de varios sectores, incluidos la academia, ciudadanía y el gobierno, resaltando el valor de una mayor participación y colaboración. Esperamos que estos hallazgos y la base de datos guíen la planificación sostenible de infraestructuras viales en Ecuador y contribuyan a reducir la mortalidad animal en las carreteras por medio de una conducción vehicular más cautelosa.

7.
Nat Commun ; 14(1): 74, 2023 01 24.
Artículo en Inglés | MEDLINE | ID: mdl-36693827

RESUMEN

Land-use and climate change have been linked to changes in wildlife populations, but the role of socioeconomic factors in driving declines, and promoting population recoveries, remains relatively unexplored. Here, we evaluate potential drivers of population changes observed in 50 species of some of the world's most charismatic and functionally important fauna-large mammalian carnivores. Our results reveal that human socioeconomic development is more associated with carnivore population declines than habitat loss or climate change. Rapid increases in socioeconomic development are linked to sharp population declines, but, importantly, once development slows, carnivore populations have the potential to recover. The context- and threshold-dependent links between human development and wildlife population health are challenges to the achievement of the UN Sustainable development goals.


Asunto(s)
Carnívoros , Cambio Climático , Animales , Humanos , Conservación de los Recursos Naturales/métodos , Ecosistema , Animales Salvajes , Factores Socioeconómicos
8.
Glob Chang Biol ; 29(5): 1282-1295, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36462155

RESUMEN

There is mounting evidence that terrestrial arthropods are declining rapidly in many areas of the world. It is unclear whether freshwater invertebrates, which are key providers of ecosystem services, are also declining. We addressed this question by analysing a long-term dataset of macroinvertebrate abundance collected from 2002 to 2019 across 5009 sampling sites in English rivers. Patterns varied markedly across taxonomic groups. Within trophic groups we detected increases in the abundance of carnivores by 19% and herbivores by 14.8%, while we estimated decomposers have declined by 21.7% in abundance since 2002. We also found heterogeneity in trends across rivers belonging to different typologies based on geological dominance and catchment altitude, with organic lowland rivers having generally higher rates of increase in abundance across taxa and trophic groups, with siliceous lowland rivers having the most declines. Our results reveal a complex picture of change in freshwater macroinvertebrate abundance between taxonomic groups, trophic levels and river typologies. Our analysis helps with identifying priority regions for action on potential environmental stressors where we discover macroinvertebrate abundance declines.


Asunto(s)
Ecosistema , Ríos , Animales , Biodiversidad , Monitoreo del Ambiente/métodos , Invertebrados
9.
Ecol Evol ; 12(1): e8436, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-35127005

RESUMEN

Diel activity patterns are an important aspect of wildlife ecology and evolution and provide valuable information for conservation and monitoring, yet for many species, activity patterns remain unstudied and may be presumed to mirror related taxa. Here, we describe the distinct diel patterns of an endemic population of venomous sea snakes Hydrophis platurus xanthos inhabiting a narrow range (circa 320 km2) in Golfo Dulce, Costa Rica. To investigate, we conducted a systematic visual survey over five 24-h cycles and evaluated 339 h of previously obtained sighting data from different studies spanning a decade. While sporadic diurnal surfacing does occur, mostly for respiration, our observations revealed marked crepuscular peaks with regular surfacing through the night. We also report on observed surface behaviors that were also found to vary in frequency at different phases of the photoperiodic cycle. In particular, we show feeding as more common at night. Hydrophis platurus xanthos has developed a circadian rhythm that differs noticeably from its taxonomic parent (H. p. platurus is reported as diurnal across its Indo-Pacific range), and no congeners have been categorized as crepuscular. Our work thus contributes to the ecological knowledge of this evolutionarily distinct marine elapid and offers insights into the potential role of environmental conditions in shaping animal activity.

10.
Trends Ecol Evol ; 37(4): 359-370, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35065822

RESUMEN

The International Union for Conservation of Nature (IUCN) Red List of Threatened Species is central in biodiversity conservation, but insufficient resources hamper its long-term growth, updating, and consistency. Models or automated calculations can alleviate those challenges by providing standardised estimates required for assessments, or prioritising species for (re-)assessments. However, while numerous scientific papers have proposed such methods, few have been integrated into assessment practice, highlighting a critical research-implementation gap. We believe this gap can be bridged by fostering communication and collaboration between academic researchers and Red List practitioners, and by developing and maintaining user-friendly platforms to automate application of the methods. We propose that developing methods better encompassing Red List criteria, systems, and drivers is the next priority to support the Red List.


Asunto(s)
Conservación de los Recursos Naturales , Especies en Peligro de Extinción , Animales , Biodiversidad , Comunicación , Extinción Biológica
11.
Ecol Evol ; 11(23): 16434-16445, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34938447

RESUMEN

Trait and functional trait approaches have revolutionized ecology improving our understanding of community assembly, species coexistence, and biodiversity loss. Focusing on traits promotes comparability across spatial and organizational scales, but terms must be used consistently. While several papers have offered definitions, it remains unclear how ecologists operationalize "trait" and "functional trait" terms. Here, we evaluate how researchers and the published literatures use these terms and explore differences among subdisciplines and study systems (taxa and biome). By conducting both a survey and a literature review, we test the hypothesis that ecologists' working definition of "trait" is adapted or altered when confronting the realities of collecting, analyzing and presenting data. From 486 survey responses and 712 reviewed papers, we identified inconsistencies in the understanding and use of terminology among researchers, but also limited inclusion of definitions within the published literature. Discrepancies were not explained by subdiscipline, system of study, or respondent characteristics, suggesting there could be an inconsistent understanding even among those working in related topics. Consistencies among survey responses included the use of morphological, phonological, and physiological traits. Previous studies have called for unification of terminology; yet, our study shows that proposed definitions are not consistently used or accepted. Sources of disagreement include trait heritability, defining and interpreting function, and dealing with organisms in which individuals are not clearly recognizable. We discuss and offer guidelines for overcoming these disagreements. The diversity of life on Earth means traits can represent different features that can be measured and reported in different ways, and thus, narrow definitions that work for one system will fail in others. We recommend ecologists embrace the breadth of biodiversity using a simplified definition of "trait" more consistent with its common use. Trait-based approaches will be most powerful if we accept that traits are at least as diverse as trait ecologists.

12.
Nat Commun ; 12(1): 2353, 2021 04 21.
Artículo en Inglés | MEDLINE | ID: mdl-33883555

RESUMEN

One key hypothesis explaining the fate of exotic species introductions posits that the establishment of a self-sustaining population in the invaded range can only succeed within conditions matching the native climatic niche. Yet, this hypothesis remains untested for individual release events. Using a dataset of 979 introductions of 173 mammal species worldwide, we show that climate-matching to the realized native climatic niche, measured by a new Niche Margin Index (NMI), is a stronger predictor of establishment success than most previously tested life-history attributes and historical factors. Contrary to traditional climatic suitability metrics derived from species distribution models, NMI is based on niche margins and provides a measure of how distant a site is inside or, importantly, outside the niche. Besides many applications in research in ecology and evolution, NMI as a measure of native climatic niche-matching in risk assessments could improve efforts to prevent invasions and avoid costly eradications.


Asunto(s)
Clima , Especies Introducidas , Mamíferos , Modelos Biológicos , Animales , Teorema de Bayes , Bases de Datos Factuales , Ecosistema , Dinámica Poblacional
13.
Sci Adv ; 7(13)2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33771870

RESUMEN

Although one-quarter of plant and vertebrate species are threatened with extinction, little is known about the potential effect of extinctions on the global diversity of ecological strategies. Using trait and phylogenetic information for more than 75,000 species of vascular plants, mammals, birds, reptiles, amphibians, and freshwater fish, we characterized the global functional spectra of each of these groups. Mapping extinction risk within these spectra showed that larger species with slower pace of life are universally threatened. Simulated extinction scenarios exposed extensive internal reorganizations in the global functional spectra, which were larger than expected by chance for all groups, and particularly severe for mammals and amphibians. Considering the disproportionate importance of the largest species for ecological processes, our results emphasize the importance of actions to prevent the extinction of the megabiota.

14.
J Anim Ecol ; 90(3): 653-661, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33354764

RESUMEN

The local abundance or population density of different organisms often varies widely. Understanding what determines this variation is an important, but not yet fully resolved question in ecology. Differences in population density are partly driven by variation in body size and diet among organisms. Here we propose that the size of an organism' brain could be an additional, overlooked, driver of mammalian population densities. We explore two possible contrasting mechanisms by which brain size, measured by its mass, could affect population density. First, because of the energetic demands of larger brains and their influence on life history, we predict mammals with larger relative brain masses would occur at lower population densities. Alternatively, larger brains are generally associated with a greater ability to exploit new resources, which would provide a competitive advantage leading to higher population densities among large-brained mammals. We tested these predictions using phylogenetic path analysis, modelling hypothesized direct and indirect relationships between diet, body mass, brain mass and population density for 656 non-volant terrestrial mammalian species. We analysed all data together and separately for marsupials and the four taxonomic orders with most species in the dataset (Carnivora, Cetartiodactyla, Primates, Rodentia). For all species combined, a single model was supported showing lower population density associated with larger brains, larger bodies and more specialized diets. The negative effect of brain mass was also supported for separate analyses in Primates and Carnivora. In other groups (Rodentia, Cetartiodactyla and marsupials) the relationship was less clear: supported models included a direct link from brain mass to population density but 95% confidence intervals of the path coefficients overlapped zero. Results support our hypothesis that brain mass can explain variation in species' average population density, with large-brained species having greater area requirements, although the relationship may vary across taxonomic groups. Future research is needed to clarify whether the role of brain mass on population density varies as a function of environmental (e.g. environmental stability) and biotic conditions (e.g. level of competition).


Asunto(s)
Carnívoros , Mamíferos , Animales , Encéfalo , Tamaño de los Órganos , Filogenia , Densidad de Población , Primates
15.
Proc Biol Sci ; 287(1922): 20192643, 2020 03 11.
Artículo en Inglés | MEDLINE | ID: mdl-32126954

RESUMEN

Concern for megafauna is increasing among scientists and non-scientists. Many studies have emphasized that megafauna play prominent ecological roles and provide important ecosystem services to humanity. But, what precisely are 'megafauna'? Here, we critically assess the concept of megafauna and propose a goal-oriented framework for megafaunal research. First, we review definitions of megafauna and analyse associated terminology in the scientific literature. Second, we conduct a survey among ecologists and palaeontologists to assess the species traits used to identify and define megafauna. Our review indicates that definitions are highly dependent on the study ecosystem and research question, and primarily rely on ad hoc size-related criteria. Our survey suggests that body size is crucial, but not necessarily sufficient, for addressing the different applications of the term megafauna. Thus, after discussing the pros and cons of existing definitions, we propose an additional approach by defining two function-oriented megafaunal concepts: 'keystone megafauna' and 'functional megafauna', with its variant 'apex megafauna'. Assessing megafauna from a functional perspective could challenge the perception that there may not be a unifying definition of megafauna that can be applied to all eco-evolutionary narratives. In addition, using functional definitions of megafauna could be especially conducive to cross-disciplinary understanding and cooperation, improvement of conservation policy and practice, and strengthening of public perception. As megafaunal research advances, we encourage scientists to unambiguously define how they use the term 'megafauna' and to present the logic underpinning their definition.


Asunto(s)
Conservación de los Recursos Naturales , Animales , Evolución Biológica , Tamaño Corporal , Extinción Biológica
16.
Ecol Lett ; 22(8): 1297-1305, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31190431

RESUMEN

Zoogeographical regions, or zooregions, are areas of the Earth defined by species pools that reflect ecological, historical and evolutionary processes acting over millions of years. Consequently, researchers have assumed that zooregions are robust and unlikely to change on a human timescale. However, the increasing number of human-mediated introductions and extinctions can challenge this assumption. By delineating zooregions with a network-based algorithm, here we show that introductions and extinctions are altering the zooregions we know today. Introductions are homogenising the Eurasian and African mammal zooregions and also triggering less intuitive effects in birds and amphibians, such as dividing and redefining zooregions representing the Old and New World. Furthermore, these Old and New World amphibian zooregions are no longer detected when considering introductions plus extinctions of the most threatened species. Our findings highlight the profound and far-reaching impact of human activity and call for identifying and protecting the uniqueness of biotic assemblages.


Asunto(s)
Anfibios , Aves , Especies en Peligro de Extinción , Actividades Humanas , Animales , Biodiversidad , Conservación de los Recursos Naturales , Extinción Biológica , Humanos , Mamíferos
17.
Conserv Biol ; 33(5): 1164-1173, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-30729579

RESUMEN

Every 2 years, the conservation community comes together at The Society for Conservation Biology's International Congress for Conservation Biology (ICCB) to share new developments in conservation science and practice. Publication of findings presented at conferences in scientific journals adds to the permanent record and helps increase the potential impact of the work presented. However, quantitative research on publication rates for meetings relevant to conservation is lacking. For the 25th ICCB, (Auckland, New Zealand in 2011), we examined study publication rates and presenter demographics, recorded titles, number of authors, presenter affiliations, gender, country of the study region, publication status, and elapsed time between presentation and publication. Of the 980 contributions (782 talks and 198 posters), 587 (60%) were published as peer-reviewed journal articles or book chapters. Mean time to publication was 13.7 months for all presentation abstracts and 21.3 months excluding abstracts with corresponding articles that were published before the meeting. The gender breakdown of presenters was almost even (53% male, 47% female), but representation of the countries where the presenting authors were based was skewed. The political units with the most contributions were by far the United States, Australia, New Zealand, and the United Kingdom. Presenters based in 16 different English-speaking countries made up 74% of the total sample, but this did not influence the likelihood of their abstract leading to a publication. Examination of conference presenters and publication of their presentations is useful to identify biases and potential challenges that need to be addressed to make conference communications permanent and increase their reach beyond conference attendees.


De Resumen de Conferencia a Publicación en la Literatura de la Ciencia de la Conservación Verde Arregoitia & González-Suárez Resumen Cada dos años, la comunidad de la conservación se reune en el Congreso Internacional para la Biología de la Conservación (ICCB, en inglés) de la Sociedad para la Biología de la Conservación y allí comparten los nuevos acontecimientos que han sucedido en la práctica y en la teoría de la conservación. La publicación en revistas científicas de los hallazgos que se presentan en las conferencias suma información al registro permanente y ayuda a incrementar el impacto potencial del trabajo presentado. Sin embargo, es muy poca la investigación cuantitativa sobre las tasas de publicación de congresos relevantes para la conservación. Para el 25to ICCB (Auckland, Nueva Zelanda, 2011) examinamos la tasa de publicación de estudios y la demografía de los presentadores, registramos los títulos, el número de autores, las afiliaciones de los presentadores, el género, el país de la región de estudio, el estado de publicación, y el tiempo transcurrido entre la presentación y la publicación. De las 980 contribuciones (782 charlas y 198 carteles) se publicaron 587 (60%) como artículos de revista con revisión por pares o como capítulos de libros. El tiempo promedio de publicación fue de 13.7 meses para todos los resúmenes de presentación y de 21.3 meses excluyendo los resúmenes con artículos correspondientes que ya habían sido publicados antes de la reunión. La proporción del género de los presentadores fue casi idéntica (53% hombres, 47% mujeres), pero la representación de los países en donde los presentadores hacen base estuvo sesgada. Las unidades políticas que contribuyeron en mayor proporción fueron, por mucho, los Estados Unidos, Australia, Nueva Zelanda, y el Reino Unido. Los presentadores localizados en 16 diferentes países angloparlantes conformaron el 74% de la muestra total, pero esto no influyó sobre la probabilidad de que su resumen derivara en una publicación. La examinación de los presentadores y la publicación de sus presentaciones es útil para identificar sesgos y retos potenciales que necesiten ser tratados para hacer que la comunicación de las conferencias sea permanente y para hacer que el alcance llegue más allá del público de las conferencias.


Asunto(s)
Indización y Redacción de Resúmenes , Conservación de los Recursos Naturales , Australia , Congresos como Asunto , Femenino , Masculino , Nueva Zelanda , Reino Unido , Estados Unidos
18.
Ecol Lett ; 22(2): 365-376, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30575254

RESUMEN

Urbanisation exposes wildlife to new challenging conditions and environmental pressures. Some mammalian species have adapted to these novel environments, but it remains unclear which characteristics allow them to persist. To address this question, we identified 190 mammals regularly recorded in urban settlements worldwide, and used phylogenetic path analysis to test hypotheses regarding which behavioural, ecological and life history traits favour adaptation to urban environments for different mammalian groups. Our results show that all urban mammals produce larger litters; whereas other traits such as body size, behavioural plasticity and diet diversity were important for some but not all taxonomic groups. This variation highlights the idiosyncrasies of the urban adaptation process and likely reflects the diversity of ecological niches and roles mammals can play. Our study contributes towards a better understanding of mammal association to humans, which will ultimately allow the design of wildlife-friendly urban environments and contribute to mitigate human-wildlife conflicts.


Asunto(s)
Ecología , Mamíferos , Urbanización , Adaptación Fisiológica , Animales , Ecosistema , Humanos , Filogenia
19.
Evolution ; 70(6): 1364-75, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27159368

RESUMEN

Although previous studies have addressed the question of why large brains evolved, we have limited understanding of potential beneficial or detrimental effects of enlarged brain size in the face of current threats. Using novel phylogenetic path analysis, we evaluated how brain size directly and indirectly, via its effects on life history and ecology, influences vulnerability to extinction across 474 mammalian species. We found that larger brains, controlling for body size, indirectly increase vulnerability to extinction by extending the gestation period, increasing weaning age, and limiting litter sizes. However, we found no evidence of direct, beneficial, or detrimental effects of brain size on vulnerability to extinction, even when we explicitly considered the different types of threats that lead to vulnerability. Order-specific analyses revealed qualitatively similar patterns for Carnivora and Artiodactyla. Interestingly, for Primates, we found that larger brain size was directly (and indirectly) associated with increased vulnerability to extinction. Our results indicate that under current conditions, the constraints on life history imposed by large brains outweigh the potential benefits, undermining the resilience of the studied mammals. Contrary to the selective forces that have favored increased brain size throughout evolutionary history, at present, larger brains have become a burden for mammals.


Asunto(s)
Evolución Biológica , Encéfalo/anatomía & histología , Extinción Biológica , Mamíferos/anatomía & histología , Mamíferos/fisiología , Animales , Tamaño Corporal , Tamaño de los Órganos
20.
Am Nat ; 185(6): 737-46, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25996859

RESUMEN

Many studies have aimed to identify common predictors of successful introductions of alien species, but the search has had limited success, particularly for animals. Past research focused primarily on mean trait values, even though genetic and phenotypic variation has been shown to play a role in establishment success in plants and some animals (mostly invertebrates). Using a global database describing 511 introduction events representing 97 mammalian species, we show that intraspecific variation in morphological traits is associated with establishment success, even when controlling for the positive effect of propagule pressure. In particular, greater establishment success is associated with more variation in adult body size but, surprisingly, less variation in neonate body size, potentially reflecting distinct trade-offs and constraints that influence population dynamics differently. We find no mean trait descriptors associated with establishment success, although species occupying wider native distribution ranges (which likely have larger niches) are more successful. Our results emphasize the importance of explicitly considering intraspecific variation to predict establishment success in animal species and generally to understand population dynamics. This understanding might improve management of alien species and increase the success of intentional releases, for example, for biocontrol or reintroductions.


Asunto(s)
Especies Introducidas , Mamíferos , Animales , Tamaño Corporal , Bases de Datos Factuales , Ecosistema , Variación Genética , Fenotipo , Dinámica Poblacional , Reproducción , Especificidad de la Especie
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