Reviewing taxonomic bias in a megadiverse country: primary biodiversity data, cultural salience, and scientific interest of South African animals

Taxonomic bias, resulting in some taxa receiving more attention than others, has been shown to persist throughout history. Such bias in primary biodiversity data needs to be addressed because the data are vital to environmental management. This study reviews taxonomic bias in South African primary biodiversity data obtained from the Global Biodiversity Information Facility (GBIF). The focus was specifically on animal classes, and regression analysis was used to assess the influence of scientific interest and cultural salience on taxonomic bias. A higher resolution analysis of the two explanatory variables’ influence on taxonomic bias is conducted using a generalised linear model on a subset of herpetofaunal families from the focal classes. Furthermore, the potential effects of cultural salience and scientific interest on a taxon’s extinction risk are investigated. The findings show that taxonomic bias in South Africa’s primary biodiversity data has similarities with global scale taxonomic bias. Among animal classes, there is strong bias towards birds while classes such as Polychaeta and Maxillopoda are under-represented. Cultural salience has a stronger influence on taxonomic bias than scientific interest. It is, however, unclear how these explanatory variables may influence the extinction risk of taxa. We recommend that taxonomic bias can be reduced if primary biodiversity data collection has a range of targets that guide (but do not limit) accumulation of species occurrence records per habitat. Within this range, a lower target of species occurrence records accommodates species that are difficult to detect. The upper target means occurrence records for any species are less urgent but nonetheless useful and thus data collection efforts can focus on species with fewer occurrence records.

The Last Two Remaining Populations of the Critically Endangered Estuarine Pipefish Are Inbred and Not Genetically Distinct

The critically endangered estuarine pipefish, Syngnathus watermeyeri, is one of Africa’s rarest fish species and currently faces a significant risk of extinction. A combination of anthropogenic and natural factors threaten submerged macrophyte beds in the two South African estuaries (Bushmans and Kariega) in which the species’ only two known remaining populations reside. Here, we genotyped 34 pipefish from both populations using genome-wide data to determine whether the two estuaries harbour distinct genetic diversity, such that translocating individuals between them might improve the genetic health of both. Our results show that both populations are highly inbred, and no statistically significant genetic structure was found between them. Moreover, individuals both within and between estuaries were very closely related to each other. These results indicate that the remaining populations of the estuarine pipefish suffer from the adverse genetic effects of small population sizes. Even though recent surveys have estimated population sizes in the order of thousands of individuals, these may fluctuate considerably. Although the translocation of genetically similar individuals between habitats will not increase local genetic diversity, the creation of additional populations across the species’ historical range may be a suitable conservation strategy to prevent further loss of genetic diversity, and to minimise the overall extinction risk posed by environmental stochasticity.

Habitat Suitability, Population Structure and Conservation Status of Pinanga arinasae (Arecaceae), an Endemic Palm in Bali Island, Indonesia

The conservation of species should be based on knowledge of habitat requirements, population structure and conservation status. This knowledge is quite important to design conservation areas for species and to promote long-term persistence. In this study, we investigated habitat suitability, population size structure and conservation status of Pinanga arinasae in Bali. Plots with palms and adjacent areas with no palms were sampled to characterize key habitat variables. Habitat suitability was modeled using Artificial Neural Network (ANN) and Random Forest (RF) methods. The population size structure was characterized by counting and measuring the height and reproductive status of the individuals found in plots. Furthermore, we assessed the extinction risk of the species using the IUCN Red List Criteria. The ANN variables that best explained occurrence were litter depth, elevation, canopy openness and slope. The RF variables that best explained the data were elevation, litter depth, slope, and aspect. Both ANN and RF are robust models that can be used to predict the occurrence of P. arinasae. The population size structure included many seedlings, but juvenile and mature individuals were found in relatively small numbers. Based on the findings, we proposed Endangered B1+B2ab(i,ii,iii,v); D as the conservation status of P. arinasae.

Extinction risk modeling predicts range-wide differences of climate change impact on Karner blue butterfly

The Karner blue butterfly (Lycaeides melissa samuelis), an endangered species in decline due to multiple factors, including habitat loss, can be further threatened by climate change. Evaluating how climate shapes the population dynamics and distribution of the Karner blue (Kbb) is necessary for developing adaptive. Demographic models generally used for insect populations are often either density-dependent or applied to population presence-absence data in a density-independent manner. In contrast, we used scale-based, mixed density-dependent and density-independent (hereafter “endo-exogenous”) models for the Kbb, based on long-term count data of abundance during flight periods, to understand how different environmental variables, including climate, affected Kbb extinction risk through the middle of the 21st century. Our endo-exogenous models showed that density-dependent and environmental variables, including climate, topography, and tree canopy coverage, were essential drivers of Kbb population dynamics. We also found that Kbb’s response to climate differed between the species’ two annual generations and across its range: higher temperature and precipitation in summer generally benefited the second-generation populations, whereas there were uncertainties of the effects on the populations in different ecoregions during the first generation. These results imply that population-specific biotic/abiotic factors need to be incorporated into plans to manage the recovery of Kbb under climate change.

Rediscovery of Laura’s glassfrog Nymphargus laurae (Anura: Centrolenidae) with new data on its morphology, colouration, phylogenetic position and conservation in Ecuador

We report the rediscovery of Laura’s Glassfrog, Nymphargus laurae Cisneros-Heredia & McDiarmid, 2007, based on two specimens collected at the Colonso-Chalupas Biological Reserve, province of Napo, Ecuador. The species was described and known from a single male specimen collected in 1955 at Loreto, north-eastern Andean foothills of Ecuador. Limited information was available about the colouration, systematics, ecology, and biogeography of N. laurae. We provide new data on the external morphology, colouration, distribution and comment on its conservation status and extinction risk. We discuss the phylogenetic relationships of N. laurae, which forms a clade together with N. siren and N. humboldti. The importance of research in unexplored areas must be a national priority to document the biodiversity associated, especially in protected areas.

A Global Red List for Hydrothermal Vent Molluscs

With the accelerating development of direct and indirect anthropogenic threats, including climate change and pollution as well as extractive industries such as deep-sea mining, there is an urgent need for simple but effective solutions to identify conservation priorities for deep-sea species. The International Union for Conservation of Nature (IUCN) Red List of Threatened Species is an effective and well-recognized tool to promote the protection of species and presents an opportunity to communicate conservation threats to industry, policy makers, and the general public. Here, we present the Vent Red List for molluscs: a complete global assessment of the extinction risk of all described molluscs endemic to hydrothermal vents, a habitat under imminent threat from deep-sea mining. Of the 184 species assessed, 62% are listed as threatened: 39 are Critically Endangered, 32 are Endangered, and 43 are Vulnerable. In contrast, the 25 species that are fully protected from deep-sea mining by local conservation measures are assessed as Least Concern, and a further 45 species are listed as Near Threatened, where some subpopulations face mining threats while others lie within protected areas. We further examined the risk to faunas at specific vent sites and biogeographic regions using a relative threat index, which highlights the imperiled status of vent fields in the Indian Ocean while other vent sites within established marine protected areas have a high proportion of species assessed as Least Concern. The Vent Red List exemplifies how taxonomy-driven tools can be utilized to support deep-sea conservation and provides a precedent for the application of Red List assessment criteria to diverse taxa from deep-sea habitats.