8 research outputs found

    Advancing ecosystem understanding: Identifying the drivers of habitat degradation, species distributions and species vulnerabilities in East African grasslands.

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    Environments are changing at an accelerated rate, as a consequence of hu- man activity. Many questions remain unanswered regarding the drivers of this change in the landscape, the mechanisms by which species are affected, and patterns of consequential species vulnerabilities. Here I use remote sensing and machine learning to investigate pathways of savannah degradation; use Bayesian species distribution models with data integration to test predictors of range shifts in savannah birds; and evaluate a common climate change vul- nerability assessment framework based on simulated data and foundational concepts. I find that the most degraded savannah sites are those that de- cline in resistance over time and tend to exhibit lower rainfall and higher human and livestock density. However, I show that the same sites do not lose their recovery potential, giving hope for their eventual restoration under correct management. I find that degradation has increased across the whole landscape, and that this increase was lowest for national parks and wildlife management areas, underlining the effectiveness of these management strate- gies for mitigating current degradation trends. Next, I find little support for broad trait-range shift relationships across taxa, for either local extinctions, local colonisations, or total change. This calls into question the usefulness of traits in vulnerability assessments of taxa, where they are applied to wider taxonomic groups. However, I also identify strong species-specific relation- ships among the results, suggesting that more research into those individual species might reveal important trait relationships. Finally, I show that vulner- ability frameworks based on separately assessed species sensitivity, exposure, and adaptive capacity, such as many trait-based approaches, are fundamen- tally unable to accurately predict true vulnerability of species. I showcase how recent advances in species distribution modelling can be applied to develop revised vulnerability metrics

    Extreme morphologies of mantis shrimp larvae

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    Larvae of stomatopods (mantis shrimps) are generally categorized into four larval types: antizoea, pseudozoea (both representing early larval stages), alima and erichthus (the latter two representing later larval stages). These categories, however, do not reflect the existing morphological diversity of stomatopod larvae, which is largely unstudied. We describe here four previously unknown larval types with extreme morphologies. All specimens were found in the collections of the Zoological Museum, University of Copenhagen and were collected during the Danish Dana Expedition round the world 1928-30. These new larval types all represent erichthus-type larvae, especially differing in their shield morphologies. The shield morphology ranges from almost spherical to rather disc-like, with sometimes extremely elongated spines, but only a general systematic assignment of the larvae was possible. Further investigations of these larvae are crucial to understand their life habits and ecological impact, especially as stomatopod and other crustacean larvae might have a much more important position in the marine ecosystems than their corresponding adults

    How many metazoan species live in the world’s largest mineral exploration region?

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    The global surge in demand for metals such as cobalt and nickel has created unprecedented interest in deep-sea habitats with mineral resources. The largest area of activity is a 6 million km2 region known as the Clarion-Clipperton Zone (CCZ) in the central and eastern Pacific, regulated by the International Seabed Authority (ISA). Baseline biodiversity knowledge of the region is crucial to effective management of environmental impact from potential deep-sea mining activities, but until recently this has been almost completely lacking. The rapid growth in taxonomic outputs and data availability for the region over the last decade has allowed us to conduct the first comprehensive synthesis of CCZ benthic metazoan biodiversity for all faunal size classes. Here we present the CCZ Checklist, a biodiversity inventory of benthic metazoa vital to future assessments of environmental impacts. An estimated 92% of species identified from the CCZ are new to science (436 named species from a total of 5,578 recorded). This is likely to be an overestimate owing to synonyms in the data but is supported by analysis of recent taxonomic studies suggesting that 88% of species sampled in the region are undescribed. Species richness estimators place total CCZ metazoan benthic diversity at 6,233 (+/−82 SE) species for Chao1, and 7,620 (+/−132 SE) species for Chao2, most likely representing lower bounds of diversity in the region. Although uncertainty in estimates is high, regional syntheses become increasingly possible as comparable datasets accumulate. These will be vital to understanding ecological processes and risks of biodiversity loss

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    Endemicity of Paragonimus and paragonimiasis in Sub-Saharan Africa: A systematic review and mapping reveals stability of transmission in endemic foci for a multi-host parasite system.

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    Paragonimiasis is caused by zoonotic trematodes of Paragonimus spp., found in Asia, the Americas and Africa, particularly in tropical regions. These parasites have a complex, multi-host life cycle, with mammalian definitive hosts and larval stages cycling through two intermediate hosts (snails and freshwater decapod crustaceans). In Africa, paragonimiasis is particularly neglected, and remains the only human parasitic disease without a fully characterised life cycle. However paragonimiasis has potentially significant impacts on public health in Africa, and prevalence has likely been underestimated through under-reporting and misdiagnosis as tuberculosis due to a similar clinical presentation. We identified the need to synthesise current knowledge and map endemic foci for African Paragonimus spp. together with Poikilorchis congolensis, a rare, taxonomically distant trematode with a similar distribution and morphology. We present the first systematic review of the literature relating to African paragonimiasis, combined with mapping of all reported occurrences of Paragonimus spp. throughout Africa, from the 1910s to the present. In human surveys, numerous reports of significant recent transmission in Southeast Nigeria were uncovered, with high prevalence and intensity of infection. Overall prevalence was significantly higher for P. uterobilateralis compared to P. africanus across studies. The potential endemicity of P. africanus in Côte d'Ivoire is also reported. In freshwater crab intermediate hosts, differences in prevalence and intensity of either P. uterobilateralis or P. africanus were evident across genera and species, suggesting differences in susceptibility. Mapping showed temporal stability of endemic foci, with the majority of known occurrences of Paragonimus found in the rainforest zone of West and Central Africa, but with several outliers elsewhere on the continent. This suggests substantial under sampling and localised infection where potential host distributions overlap. Our review highlights the urgent need for increased sampling in active disease foci in Africa, particularly using molecular analysis to fully characterise Paragonimus species and their hosts

    Extreme morphologies of mantis shrimp larvae

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    ABSTRACT Larvae of stomatopods (mantis shrimps) are generally categorized into four larval types: antizoea, pseudozoea (both representing early larval stages), alima and erichthus (the latter two representing later larval stages). These categories, however, do not reflect the existing morphological diversity of stomatopod larvae, which is largely unstudied. We describe here four previously unknown larval types with extreme morphologies. All specimens were found in the collections of the Zoological Museum, University of Copenhagen and were collected during the Danish Dana Expedition round the world 1928-30. These new larval types all represent erichthus-type larvae, especially differing in their shield morphologies. The shield morphology ranges from almost spherical to rather disc-like, with sometimes extremely elongated spines, but only a general systematic assignment of the larvae was possible. Further investigations of these larvae are crucial to understand their life habits and ecological impact, especially as stomatopod and other crustacean larvae might have a much more important position in the marine ecosystems than their corresponding adults

    Interactive effects of elevation and newly paved road on avian community composition in a scientific reserve, Bioko Island, Equatorial Guinea

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    Understanding interactive effects between anthropogenic disturbance and abiotic factors on species turnover can help to identify and prioritize conservation of potentially vulnerable tropical bird communities. We investigated the potential factors influencing avian understory community composition along with a recently constructed road across three elevations (300, 800, and 1200 m), each with two sampling sites (road edge vs. interior forest), over a four-year period on Bioko Island, Equatorial Guinea. Insectivorous species were the most abundant guild-sampled accounting for 55% of total species diversity within the dataset followed by frequent mixed-flock followers (48%). Habitat associated with elevation was the most significant factor influencing the composition of avian communities. Additionally, we identified species with clear statistical associations for each elevation: the yellow-lored bristlebill (Bleda notatus), olive sunbird (Cyanomitra obscura), and white-tailed warbler (Poliolias lopezi). We found evidence for significant community differences between the disturbance edge and interior forest transects at 300 m only. Likewise, understory insectivores were found at higher numbers within the interior forest transect at this elevation. Based on the data presented here, we suggest low elevation avian understory insectivores should be considered focal species for future assessment studies in this area. Furthermore, since many traditional protected areas focus on upland habitat containing high species endemism, our findings emphasize the importance of equally conserving lowland elevations as they may house commonly overlooked, yet important and diverse segments of the bird community. Abstract in Spanish is available with online material
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