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1.
PLoS One ; 19(5): e0299783, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38748670

RESUMEN

Unsustainable trade in big cats affects all species in the genus, Panthera, and is one of the foremost threats to their conservation. To provide further insight into the impact of policy interventions intended to address this issue, we examine the case study of the Republic of Korea (South Korea), which in the early 1990s was one of the world's largest importers of tiger (Panthera tigris) bone and a major manufacturer of tiger-derived medicinal products. In 1993, South Korea became a Party to the Convention on International Trade in Endangered Species (CITES) and introduced a ban on commercial trade in CITES Appendix I-listed big cats a year later. We used an expert-based questionnaire survey and an exploration of the CITES trade database to investigate what has since happened to big cat trade in South Korea. Expert opinion suggested that big cat trade has likely substantially reduced since the early 1990s, as a result of the trade ban and broad socioeconomic changes. However, illegal trade has not been eradicated entirely and we were able to confirm that products reportedly derived from big cats were still publicly available for sale on a range of Korean online marketplaces, sometimes openly. The items most commonly reported by respondents from post-1994 trade and supported by expert-led evidence were tiger and leopard (Panthera pardus) skins and tiger bone wine. Although South Korea may provide a useful case study of a historically significant consumer country for tiger which has made strong progress in addressing unsustainable levels of big cat trade within a short period of time, there remains a need to address recalcitrant small-scale, illegal trade. We also recommend further investigation regarding reports of South Korean nationals being involved in illegal trade in tiger-derived products in Southeast Asia.


Asunto(s)
Comercio , Conservación de los Recursos Naturales , Especies en Peligro de Extinción , República de Corea , Animales , Comercio/tendencias , Conservación de los Recursos Naturales/legislación & jurisprudencia , Conservación de los Recursos Naturales/tendencias , Especies en Peligro de Extinción/legislación & jurisprudencia , Especies en Peligro de Extinción/tendencias , Especies en Peligro de Extinción/estadística & datos numéricos , Tigres , Panthera , Encuestas y Cuestionarios , Gatos
2.
PLoS One ; 19(5): e0300371, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38753613

RESUMEN

Chameleons (family Chamaeleonidae) are a distinctive group of reptiles, mainly found in Africa, which have high local endemism and face significant threats from the international wildlife trade. We review the scale and structure of international chameleon trade, with a focus on collection in and exports from Tanzania; a hotspot of chameleon diversity. Analysis used data from the CITES Trade Database 2000-2019, combined with assessment of online trade, and on-the-ground surveys in Tanzania in 2019. Between 2000 and 2019, 1,128,776 live chameleons from 108 species were reported as exported globally, with 193,093 of these (from 32 species) exported by Tanzania. Both global and Tanzanian chameleon exports declined across the study period, driven by decreased trade in generalist genera. Whilst the proportion of captive-bred individuals increased across time for the generalist taxa, the majority of range-restricted taxa in trade remained largely wild-sourced. For Tanzanian exports, 41% of chameleons were from one of the 23 endemic species, and 10 of the 12 Tanzanian endemic species in trade are categorised as threatened with extinction by IUCN. In terms of online trade, of the 42 Tanzanian species assessed, there was evidence of online sale for 83.3% species, and 69% were actively for sale with prices listed. Prices were on average highest for Trioceros species, followed by Kinyongia, Rieppeleon, Rhampholeon, and Chameleo. Field work in Tanzania provided evidence that the historic harvest of endemic chameleon species has been higher than the quantities of these species reported as exported by Tanzania in their annual trade reports to CITES. However, we found no field evidence for trade in 2020 and 2021, in line with Tanzanian regulations that applied a blanket ban on all exports of live wild animals. Literature evidence, however, suggests that illegal trade continued to Europe from seizures of Tanzanian chameleon species in Austria in 2021.


Asunto(s)
Animales Salvajes , Comercio , Conservación de los Recursos Naturales , Lagartos , Animales , Tanzanía , Especies en Peligro de Extinción/estadística & datos numéricos , Especies en Peligro de Extinción/tendencias , Biodiversidad , Comercio de Vida Silvestre
3.
BMC Ecol Evol ; 24(1): 64, 2024 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-38764016

RESUMEN

Flying foxes of the genus Pteropus, especially those inhabiting islands, face increasing pressure from anthropogenic threats. A first step to implementing effective conservation actions is to establish monitoring projects to understand a species' population status and trend. Pteropus species are highly affected by seasonality which further requires regular, repeated, and long-term data to understand population trends, and reactions to severe weather events. In the present case study, a regular, bi-annual population census was implemented on Comoros between 2016 and 2023 for the highly threatened Livingstone's fruit bat, Pteropus livingstonii, and compared the results of standardized monitoring to historical population data. Seasonality had a large impact on the number of bats found at roost sites, with more bats present in the wet season, but the data over the past eight years revealed no significant in- or decrease in the number of bats counted on the island Anjouan. We estimated around 1,200-1,500 bats on Anjouan and 300-400 bats on Mohéli, and found that landcover type has no measurable effect on population distribution at roost sites. Our study highlights the need for long-term surveys to understand past population trends and that single counts are not sufficient to draw final conclusions of a species' status.


Asunto(s)
Quirópteros , Especies en Peligro de Extinción , Estaciones del Año , Animales , Comoras/epidemiología , Especies en Peligro de Extinción/tendencias , Especies en Peligro de Extinción/estadística & datos numéricos , Dinámica Poblacional/tendencias , Conservación de los Recursos Naturales/tendencias , Densidad de Población
4.
Proc Natl Acad Sci U S A ; 121(18): e2316417121, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38648477

RESUMEN

Human actions are causing widespread increases in fire size, frequency, and severity in diverse ecosystems globally. This alteration of fire regimes is considered a threat to numerous animal species, but empirical evidence of how fire regimes are shifting within both threatened species' ranges and protected areas is scarce, particularly at large spatial and temporal scales. We used a big data approach to quantify multidecadal changes in fire regimes in southern Australia from 1980 to 2021, spanning 415 reserves (21.5 million ha) and 129 threatened species' ranges including birds, mammals, reptiles, invertebrates, and frogs. Most reserves and threatened species' ranges within the region have experienced declines in unburnt vegetation (≥30 y without fire), increases in recently burnt vegetation (≤5 y since fire), and increases in fire frequency. The mean percentage of unburnt vegetation within reserves declined from 61 to 36% (1980 to 2021), whereas the mean percentage of recently burnt vegetation increased from 20 to 35%, and mean fire frequency increased by 32%, with the latter two trends primarily driven by the record-breaking 2019 to 2020 fire season. The strongest changes occurred for high-elevation threatened species, and reserves of high elevation, high productivity, and strong rainfall decline, particularly in the southeast of the continent. Our results provide evidence for the widely held but poorly tested assumption that threatened species are experiencing widespread declines in unburnt habitat and increases in fire frequency. This underscores the imperative for developing management strategies that conserve fire-threatened species in an increasingly fiery future.


Asunto(s)
Conservación de los Recursos Naturales , Ecosistema , Especies en Peligro de Extinción , Incendios , Especies en Peligro de Extinción/tendencias , Animales , Australia , Reptiles , Mamíferos , Humanos , Aves/fisiología , Biodiversidad
6.
Nature ; 622(7982): 308-314, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37794184

RESUMEN

Systematic assessments of species extinction risk at regular intervals are necessary for informing conservation action1,2. Ongoing developments in taxonomy, threatening processes and research further underscore the need for reassessment3,4. Here we report the findings of the second Global Amphibian Assessment, evaluating 8,011 species for the International Union for Conservation of Nature Red List of Threatened Species. We find that amphibians are the most threatened vertebrate class (40.7% of species are globally threatened). The updated Red List Index shows that the status of amphibians is deteriorating globally, particularly for salamanders and in the Neotropics. Disease and habitat loss drove 91% of status deteriorations between 1980 and 2004. Ongoing and projected climate change effects are now of increasing concern, driving 39% of status deteriorations since 2004, followed by habitat loss (37%). Although signs of species recoveries incentivize immediate conservation action, scaled-up investment is urgently needed to reverse the current trends.


Asunto(s)
Anfibios , Cambio Climático , Ecosistema , Especies en Peligro de Extinción , Animales , Anfibios/clasificación , Biodiversidad , Cambio Climático/estadística & datos numéricos , Conservación de los Recursos Naturales/economía , Conservación de los Recursos Naturales/tendencias , Especies en Peligro de Extinción/estadística & datos numéricos , Especies en Peligro de Extinción/tendencias , Extinción Biológica , Riesgo , Urodelos/clasificación
7.
Nature ; 622(7981): 101-106, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37758956

RESUMEN

Protected areas (PAs) are the primary strategy for slowing terrestrial biodiversity loss. Although expansion of PA coverage is prioritized under the Convention on Biological Diversity, it remains unknown whether PAs mitigate declines across the tetrapod tree of life and to what extent land cover and climate change modify PA effectiveness1,2. Here we analysed rates of change in abundance of 2,239 terrestrial vertebrate populations across the globe. On average, vertebrate populations declined five times more slowly within PAs (-0.4% per year) than at similar sites lacking protection (-1.8% per year). The mitigating effects of PAs varied both within and across vertebrate classes, with amphibians and birds experiencing the greatest benefits. The benefits of PAs were lower for amphibians in areas with converted land cover and lower for reptiles in areas with rapid climate warming. By contrast, the mitigating impacts of PAs were consistently augmented by effective national governance. This study provides evidence for the effectiveness of PAs as a strategy for slowing tetrapod declines. However, optimizing the growing PA network requires targeted protection of sensitive clades and mitigation of threats beyond PA boundaries. Provided the conditions of targeted protection, adequate governance and well-managed landscapes are met, PAs can serve a critical role in safeguarding tetrapod biodiversity.


Asunto(s)
Biodiversidad , Conservación de los Recursos Naturales , Especies en Peligro de Extinción , Filogenia , Vertebrados , Animales , Aves/clasificación , Conservación de los Recursos Naturales/métodos , Conservación de los Recursos Naturales/estadística & datos numéricos , Vertebrados/clasificación , Especies en Peligro de Extinción/estadística & datos numéricos , Especies en Peligro de Extinción/tendencias , Anfibios/clasificación , Reptiles/clasificación , Calentamiento Global/estadística & datos numéricos
8.
Proc Natl Acad Sci U S A ; 119(4)2022 01 25.
Artículo en Inglés | MEDLINE | ID: mdl-35042806

RESUMEN

Globally, 15,521 animal species are listed as threatened by the International Union for the Conservation of Nature, and of these less than 3% have genomic resources that can inform conservation management. To combat this, global genome initiatives are developing genomic resources, yet production of a reference genome alone does not conserve a species. The reference genome allows us to develop a suite of tools to understand both genome-wide and functional diversity within and between species. Conservation practitioners can use these tools to inform their decision-making. But, at present there is an implementation gap between the release of genome information and the use of genomic data in applied conservation by conservation practitioners. In May 2020, we launched the Threatened Species Initiative and brought a consortium of genome biologists, population biologists, bioinformaticians, population geneticists, and ecologists together with conservation agencies across Australia, including government, zoos, and nongovernment organizations. Our objective is to create a foundation of genomic data to advance our understanding of key Australian threatened species, and ultimately empower conservation practitioners to access and apply genomic data to their decision-making processes through a web-based portal. Currently, we are developing genomic resources for 61 threatened species from a range of taxa, across Australia, with more than 130 collaborators from government, academia, and conservation organizations. Developed in direct consultation with government threatened-species managers and other conservation practitioners, herein we present our framework for meeting their needs and our systematic approach to integrating genomics into threatened species recovery.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Especies en Peligro de Extinción/legislación & jurisprudencia , Genómica/normas , Animales , Recolección de Datos , Especies en Peligro de Extinción/tendencias , Genoma , Genómica/legislación & jurisprudencia , Genómica/métodos , Gobierno
9.
Nat Commun ; 12(1): 5946, 2021 10 12.
Artículo en Inglés | MEDLINE | ID: mdl-34642336

RESUMEN

Recently reported insect declines have raised both political and social concern. Although the declines have been attributed to land use and climate change, supporting evidence suffers from low taxonomic resolution, short time series, a focus on local scales, and the collinearity of the identified drivers. In this study, we conducted a systematic assessment of insect populations in southern Germany, which showed that differences in insect biomass and richness are highly context dependent. We found the largest difference in biomass between semi-natural and urban environments (-42%), whereas differences in total richness (-29%) and the richness of threatened species (-56%) were largest from semi-natural to agricultural environments. These results point to urbanization and agriculture as major drivers of decline. We also found that richness and biomass increase monotonously with increasing temperature, independent of habitat. The contrasting patterns of insect biomass and richness question the use of these indicators as mutual surrogates. Our study provides support for the implementation of more comprehensive measures aimed at habitat restoration in order to halt insect declines.


Asunto(s)
Agricultura/estadística & datos numéricos , Conservación de los Recursos Naturales/métodos , Especies en Peligro de Extinción/tendencias , Insectos/fisiología , Urbanización/tendencias , Animales , Biodiversidad , Biomasa , Cambio Climático , Conservación de los Recursos Naturales/legislación & jurisprudencia , Ecosistema , Alemania , Insectos/clasificación
10.
PLoS One ; 16(9): e0256843, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34591856

RESUMEN

Understanding the responses of different ontogenetic stages to environmental and human disturbance factors is essential for developing efficient conservation strategies for endangered plant species. We examined how three ontogenetic stages of a locally endangered tree species, Olea europaea subsp. cuspidata, responded to environmental factors and human disturbance in Hugumburda dry Afromontane forest in Ethiopia. We counted individual seedlings, saplings and adults of O. europaea in 70 20 × 20 m quadrats over ca. 2.8 ha, and measured biotic (woody species richness, canopy cover, aboveground tree biomass, herbaceous cover), abiotic (soil and topographic variables), and human disturbance factors (logging and tracks). To detect ontogenetic niche shifts, we compared observed vs. simulated locations of trees in the three life stages and how they related to the environmental and human disturbance factors. We found that the population structure of O. europaea showed generally low recruitment, with few seedlings per hectare compared with the abundance of saplings and adults. The probability of finding O. europaea individuals was influenced by biotic (woody species richness) and abiotic (soil depth, slope) environmental conditions and human disturbance (logging intensity), but the direction, strength and shape of the relationships differed between seedling, sapling and adult life stages, indicating ontogenetic niche shifts. All life stages showed a positive relationship with elevation. The observed environmental niches of the different lifestages of O. europaea, and their association with human disturbance levels, should be considered when conservation strategies are developed for this species. Human disturbance in terms of logging decreases the abundance of saplings, but may facilitate emerging seedlings through creation of gaps with improved light conditions. Recruitment is, however, very low in the study area, and seedlings should be protected from browsing to enhance survival. Woody species richness in general should be conserved to optimize conditions also for O. europaea saplings.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Especies en Peligro de Extinción/tendencias , Agricultura Forestal/ética , Olea/fisiología , Plantones/fisiología , Ecosistema , Etiopía , Agricultura Forestal/métodos , Bosques , Humanos , Suelo/química , Madera/análisis
11.
Sci Rep ; 11(1): 18369, 2021 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-34526619

RESUMEN

As pollinators, hummingbirds play a critical role for both the function of ecological communities and in providing ecosystem services for people. To examine the conservation status of North American hummingbirds, we analyzed Breeding Bird Survey data for 8 species and 3 genera from 1970 to 2019 (long-term) and from 2009 to 2019 (short-term, approximately three generations). Among the Selasphorus genus, Allen's, rufous, and broad-tailed hummingbirds have declined since 1970, and the rate of decline increased from 2009 to 2019. Contrasting the trends from the past half-century, ruby-throated hummingbirds of Eastern North America have declined since approximately 2004 throughout most of the species' breeding range. In contrast, Anna's hummingbird populations have increased dramatically since 1970 in their range in western North America. We also tested whether apparent declines might be due to a growing mismatch between the timing of breeding and the timing of BBS surveys. We found no evidence for such an effect, thus supporting the hypothesis that trends reflect true demographic change. Our analyses and geographic modelling highlight the urgent need of regulatory action to conserve hummingbirds uniquely capable of filling their niche in North America.


Asunto(s)
Aves/fisiología , Especies en Peligro de Extinción/tendencias , Animales , Ecosistema , América del Norte
12.
Sci Rep ; 11(1): 16927, 2021 08 19.
Artículo en Inglés | MEDLINE | ID: mdl-34413393

RESUMEN

Climate change is modifying the hydrological and thermal regimes of rivers worldwide, threatening the triggering of organisms' key life-cycle processes. European eel (Anguilla anguilla) is a critically endangered fish species that migrates over several thousand kilometres between its rearing habitats in continental waters of Europe and North Africa and its spawning area in the Sargasso Sea. Downstream migration of adult eels occurs during periods of decreasing river water temperature associated with high discharge but changes in these environmental cues may affected eel migratory conditions. An innovative multivariate method was developed to analyse long-term datasets of daily water temperature, discharge and eel passage in two European rivers. Over the past 50 years, water temperature and discharge increased in both rivers during the downstream migration period from August to November. Silver eels preferentially migrated at temperatures between 10 and 20 °C combined with high discharge. Environmental changes have resulted in the migration of silver eels under warmer water temperatures. This example illustrates how the changes in environmental cues have led to a growing mismatch between the migratory conditions preferentially selected and those actually used, which may threaten the completion of the eel's life cycle and ultimately the persistence of this already critically endangered species.


Asunto(s)
Anguilla , Cambio Climático , Especies en Peligro de Extinción/tendencias , Ríos , Animales , Irlanda , Noruega , Temperatura
13.
PLoS One ; 16(5): e0249633, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34010302

RESUMEN

Climate change is having profound effects on the distributions of species globally. Trait-based assessments predict that specialist and range-restricted species are among those most likely to be at risk of extinction from such changes. Understanding individual species' responses to climate change is therefore critical for informing conservation planning. We use an established Species Distribution Modelling (SDM) protocol to describe the curious range-restriction of the globally threatened White-tailed Swallow (Hirundo megaensis) to a small area in southern Ethiopia. We find that, across a range of modelling approaches, the distribution of this species is well described by two climatic variables, maximum temperature and dry season precipitation. These same two variables have been previously found to limit the distribution of the unrelated but closely sympatric Ethiopian Bush-crow (Zavattariornis stresemanni). We project the future climatic suitability for both species under a range of climate scenarios and modelling approaches. Both species are at severe risk of extinction within the next half century, as the climate in 68-84% (for the swallow) and 90-100% (for the bush-crow) of their current ranges is predicted to become unsuitable. Intensive conservation measures, such as assisted migration and captive-breeding, may be the only options available to safeguard these two species. Their projected disappearance in the wild offers an opportunity to test the reliability of SDMs for predicting the fate of wild species. Monitoring future changes in the distribution and abundance of the bush-crow is particularly tractable because its nests are conspicuous and visible over large distances.


Asunto(s)
Cambio Climático , Cuervos/fisiología , Especies en Peligro de Extinción/tendencias , Golondrinas/fisiología , Distribución Animal , Animales , Ecosistema , Etiopía , Modelos Estadísticos
14.
PLoS One ; 16(5): e0245030, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34010309

RESUMEN

Dam removal is an increasingly important method of stream restoration, but most removal efforts are under-studied in their effects. In order to better understand the effects of such removals on the stream ecosystem, we examined changes in stream macroinvertebrate communities from 2011-2016. Comparisons were focused above, below, and before and after the October 2012 removal of the Brown Bridge Dam on the Boardman River in Michigan (USA), as well as to new channel sites created in its former reservoir (2013-2015). Using linear mixed-effect models on the percent abundance of ecologically sensitive taxa (% Ephemeroptera, Plecoptera, Trichoptera (EPT)), total density of all macroinvertebrates, overall taxa richness, and Functional Feeding Groups, along with multivariate analyses on the community matrix, we examined differences in community composition among sites and years. EPT declined downstream of the dam immediately after dam removal, but recovered in the second year, becoming dominant within 2-4 years. Downstream sites before removal had different community composition than upstream sites and downstream sites after removal (p<0.001), while upstream and downstream sites after removal converged towards similarity. New channel (restored) %EPT, density, and taxa richness were not different from upstream sites in any year following removal, but new channel sites were the most distinct in community composition, possessing multiple indicator taxa characteristic of unique new conditions. The invasive New Zealand mud snail (Potamopyrgus antipodarum) was absent from all sites prior to dam removal, but appeared at low densities in upstream sites in 2013, had spread to all sites by 2015, and showed large increases at all sites by 2016. Managers employing dam removal for stream restoration should include post-removal monitoring for multiple years following removal and conduct risk analysis regarding potential effects on colonization of invasive invertebrate species.


Asunto(s)
Organismos Acuáticos/fisiología , Biomasa , Especies en Peligro de Extinción/tendencias , Animales , Insectos/fisiología , Michigan , Ríos , Caracoles/fisiología
15.
PLoS One ; 16(5): e0249966, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33939716

RESUMEN

Coral transplantation has been used in reef restoration for several decades, but information on the type of projects, their scope, scale, and success is mostly limited to published scientific studies and technical reports. Many practitioners do not have the capacity to share their progress in peer-reviewed literature, yet likely have a wealth of information to share on how to improve the efficiency of transplantation efforts. In order to incorporate non-published data on coral transplantation projects and gain an overview of the general features of these projects, we conducted an initial systematic online survey of projects run by various practitioners. Surveyed projects (n = 50) covered most of the tropical belt and ranged in size from a few hundred transplanted corals to >5000 transplants. The most frequent source of coral fragments were corals already broken from some previous impact ("corals of opportunity"; 58% of projects), followed by fragments stored in different types of aquaculture systems (42% of projects). The use of sexual reproduction was very limited. Fast-growing, branching corals were used in 96% of projects, being by far the most common transplanted growth form. About half of the projects mentioned undertaking maintenance of the transplantation plots. The majority of projects undertook subsequent monitoring (80%), yet the available data indicates that duration of monitoring efforts was not adequate to evaluate long-term success. The findings underline that while some general principles for successful coral restoration projects are reasonably well established, others need to be mainstreamed better in order to improve the effectiveness of coral transplantation for reef restoration. This relates in particular to sustainable funding, adequate site assessment, and long-term monitoring using established protocols. Additional information is needed to better understand and address potential challenges with regards to the sourcing of transplants and use of slow-growing species. A better integration of practitioners is necessary to improve the understanding of coral transplantation effectiveness. The results underline a need to develop and use monitoring protocols that allow gauging and comparing the effectiveness of coral transplantation among various projects, as well as for accessible platform(s) to allow the exchange of experiences made in different projects. Regular surveys of restoration projects are recommended to collate and share information among practitioners. We provide a number of recommendations for items to include in future surveys.


Asunto(s)
Arrecifes de Coral , Especies en Peligro de Extinción/tendencias , Restauración y Remediación Ambiental/métodos , Restauración y Remediación Ambiental/tendencias , Humanos , Investigadores , Encuestas y Cuestionarios
16.
PLoS One ; 16(2): e0240002, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33626057

RESUMEN

A broad panel of potentially amplifiable microsatellite loci and a multiplex system were developed for the Amazonian symbol fish species Arapaima gigas, which is currently in high danger of extinction due to the disorderly fishing exploitation. Several factors have contributed to the increase of this threat, among which we highlight the lack of genetic information about the structure and taxonomic status of the species, as well as the lack of accurate tools for evaluation of the effectivity of current management programs. Based on Arapaima gigas' whole genome, available at the NCBI database (ID: 12404), a total of 95,098 unique perfect microsatellites were identified, including their proposed primers. From this panel, a multiplex system containing 12 tetranucleotide microsatellite markers was validated. These tools are valuable for research in as many areas as bioinformatics, ecology, genetics, evolution and comparative studies, since they are able to provide more accurate information for fishing management, conservation of wild populations and genetic management of aquaculture.


Asunto(s)
Conservación de los Recursos Naturales/métodos , Peces/clasificación , Peces/genética , Animales , Cartilla de ADN/genética , Especies en Peligro de Extinción/tendencias , Variación Genética/genética , Genoma/genética , Genómica/métodos , Repeticiones de Microsatélite/genética , Ríos , América del Sur
17.
Genomics ; 113(2): 681-692, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33508445

RESUMEN

Acer (Sapindaceae) is an exceptional study system for understanding the evolutionary history, divergence, and assembly of broad-leaved deciduous forests at higher latitudes. Maples stand out due to their high diversity, disjunct distribution pattern across the northern continents, and rich fossil record dating back to the Paleocene. Using a genome-wide supermatrix combining plastomes and nuclear sequences (~585 kb) for 110 Acer taxa, we built a robust time-calibrated hypothesis investigating the evolution of maples, inferring ancestral ranges, reconstructing diversification rates over time, and exploring the impact of mass-extinction on lineage accumulation. Contrary to fossil evidence, our results indicate Acer first originated in the (north)eastern Palearctic region, which acted as a source for recurring outward migration. Warm conditions favored rapid Eocene-onward divergence, but ranges and diversity declined extensively as a result of the Plio-Pleistocene glacial cycles. These signals in genome-wide sequence data corroborate paleobotanical evidence for other major woody north-temperate groups, highlighting the significant (disparate) impact of climatic changes on the evolution, composition, and distribution of the vegetation in the northern hemisphere.


Asunto(s)
Acer/genética , Evolución Molecular , Especiación Genética , Filogenia , Polimorfismo Genético , Acer/clasificación , Biomasa , Cambio Climático , Especies en Peligro de Extinción/tendencias , Fósiles , Genoma de Planta , Filogeografía
18.
PLoS One ; 16(1): e0238669, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33471868

RESUMEN

While the international pet trade and habitat destruction have been extensively discussed as major threats to the survival of the pancake tortoise (Malacochersus tornieri), the impact of climate change on the species remains unknown. In this study, we used species distribution modelling to predict the current and future distribution of pancake tortoises in Zambezian and Somalian biogeographical regions. We used 224 pancake tortoise occurrences obtained from Tanzania, Kenya and Zambia to estimate suitable and stable areas for the pancake tortoise in all countries present in these regions. We also used a protected area network to assess how many of the suitable and stable areas are protected for the conservation of this critically endangered species. Our model predicted the expansion of climatically suitable habitats for pancake tortoises from four countries and a total area of 90,668.75 km2 to ten countries in the future and an area of 343,459.60-401,179.70 km2. The model also showed that a more significant area of climatically suitable habitat for the species lies outside of the wildlife protected areas. Based on our results, we can predict that pancake tortoises may not suffer from habitat constriction. However, the species will continue to be at risk from the international pet trade, as most of the identified suitable habitats remain outside of protected areas. We suggest that efforts to conserve the pancake tortoise should not only focus on protected areas but also areas that are unprotected, as these comprise a large proportion of the suitable and stable habitats available following predicted future climate change.


Asunto(s)
Conservación de los Recursos Naturales/tendencias , Tortugas , África Oriental , Animales , Animales Salvajes , Cambio Climático/estadística & datos numéricos , Conservación de los Recursos Naturales/métodos , Ecosistema , Especies en Peligro de Extinción/estadística & datos numéricos , Especies en Peligro de Extinción/tendencias , Kenia , Modelos Estadísticos , Tanzanía , Zambia
19.
PLoS One ; 15(10): e0239182, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33112860

RESUMEN

The koala (Phascolarctos cinereus) is currently listed by both the IUCN and the Australian Governments' Threatened Species Scientific Committee as vulnerable to extinction with an overall decreasing population trend. It is unknown exactly how many koalas remain in the wild, but it is known that habitat fragmentation and bushfires have ultimately contributed to the decline of the koala all over Australia. This novel study is a retrospective analysis of data over a 29-year period (1989-2018) using records for 12,543 sightings and clinical care admissions for wild koalas from the major koala hot-spots (Port Stephens, port Macquarie and Lismore) in New South Wales, Australia. This study aims to understand the long-term patterns and trends of key stressors that are contributing to the decline of koalas in New South Wales, and the synergic interactions of factors such as rescue location, sex and age of the koala, and if their decline is influenced progressively by year. The main findings of this retrospective analysis indicated that between all 3 rescue sites, the most common prognosis was disease, the most common disease was signs of chlamydia, and the most common outcome was release. The location where the highest number of koalas were found prior to being reported as sighted or admitted into clinical care was within the regional area of Lismore. Furthermore, sex was not a discriminating factor when it came to prognosis or outcome, but age was significant. Finally, incidents of disease were found to increase over long-term, whereas release decreased over time and euthanasia increased. The wealth of data available to us and the retrospective analysis enabled us in a way to 'zoom out' and reveal how the key environmental stressors have fluctuated spatially and temporally. In conclusion, our data provides strong evidence of added pressures of increased human population growth in metropolitan zones, which increases risks of acute environmental trauma and proximate stressors such as vehicle collisions and dog-attacks as well as increased sightings of virtually healthy koalas found in exposed environments. Thus our 'zoom out' approach provides support that there is an urgent need to strengthen on-ground management, bushfire control regimes, environmental planning and governmental policy actions that should hopefully reduce the proximate environmental stressors in a step wise approach. This will ensure that in the next decade (beyond 2020), NSW koalas will hopefully start to show reversed trends and patterns in exposure to environmental trauma and disease, and population numbers will return towards recovery and stability.


Asunto(s)
Especies en Peligro de Extinción , Phascolarctidae , Animales , Infecciones por Chlamydia/veterinaria , Conservación de los Recursos Naturales/historia , Conservación de los Recursos Naturales/tendencias , Demografía/historia , Demografía/tendencias , Ecosistema , Especies en Peligro de Extinción/tendencias , Femenino , Historia del Siglo XX , Historia del Siglo XXI , Masculino , Nueva Gales del Sur , Phascolarctidae/microbiología , Pronóstico , Estudios Retrospectivos
20.
PLoS One ; 15(8): e0236146, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32760084

RESUMEN

The smalltail shark, Carcharhinus porosus, was the most abundant elasmobranch species in fisheries off Brazil's northern coast (BNC) in the 1980s, but its population has been declining since the 1990s. For this reason, a demographic analysis is necessary to determine the extent of this decline and the fishing effect on the BNC's population. Therefore, we performed a stochastic demographic analysis of the population in the BNC, and considered its global center of abundance. Smalltail shark specimens (n = 937) were collected with gillnets in Maranhão state, eastern BNC, in the 1980s with sizes ranging between 29.6 and 120.0 cm total length. Most of the individuals (90.6%) caught were juveniles (< 6 years-old), and the mortality and exploitation rates showed that the species was overexploited (92.3% above the fishing mortality corresponding to the population equilibrium threshold). The smalltail shark's biological characteristics, such as slow growth and low fecundity, demonstrate that it is one of the least resilient species among similar sized coastal sharks in the region. All these factors yielded an annual decrease of 28% in the intrinsic population growth rate, resulting in a population decline of more than 90% in only 10 years, and much higher for the current period. This set of features comprising fishing recruitment occurring upon juveniles, overfishing, and intrinsically low resilience make the population unable to sustain fishing pressure and severely hamper biological recruitment, thus causing this drastic population decline. Furthermore, several local extinctions for this species in the northeastern and southeastern regions of Brazil highlight its concerning conservation scenario. Therefore, since similar fisheries characteristics occur throughout its distribution range, C. porosus fits the criteria E of the IUCN Red List for a critically endangered species and urgent conservation measures are needed to prevent its extinction in the near future.


Asunto(s)
Distribución Animal , Especies en Peligro de Extinción/estadística & datos numéricos , Explotaciones Pesqueras/estadística & datos numéricos , Dinámica Poblacional/estadística & datos numéricos , Tiburones/fisiología , Factores de Edad , Animales , Brasil , Seguimiento de Parámetros Ecológicos/estadística & datos numéricos , Especies en Peligro de Extinción/tendencias , Fertilidad/fisiología , Explotaciones Pesqueras/tendencias , Dinámica Poblacional/tendencias , Maduración Sexual/fisiología
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