Greater Risk Of Extinction Research Articles

Taxonomy as the first step towards conservation: an appraisal on the taxonomy of medium- and large-sized Neotropical mammals in the 21st century

The Anthropocene brought an accelerated risk of extinction for species across the globe. However, extinction proneness is not even across groups. Past and current events show large-sized mammals at greater extinction risk than smaller ones. For practical reasons, conservation actions tend to focus on the species level; therefore, well-founded species limits are pivotal. Since 2005, the number of known mammal species is about 20% higher but largely due to taxonomic discoveries in small-sized taxa. Here we review the recent taxonomic advances on medium- and large-sized mammals (MLM) from the Neotropics, and discuss misperceptions concerning the taxonomy stability in this group and how this may hinder proper conservation actions. We advocate that apparent taxonomic inertia toward large-sized mammals is partly related to limited systematic inquiry rather than representing an accurate knowledge of their diversity. Fortunately, this scenario has slowly changed in recent years. Linked to integrative analyses that took place during the 21st century, the Neotropical region represents a major example of recent growth in MLM diversity. Taxonomic novelties were found in eight orders of MLM and occurred across taxonomic ranks, from family to subspecies. Most changes comprise subspecies or synonyms elevated to full species, but new taxa of Artiodactyla, Carnivora, Lagomorpha, Pilosa, Primates, Perissodactyla, and large rodents have also been discovered. Recent reshuffles in MLM classification clearly illustrate the risk that bias in taxonomy studies can bring to conservation. Considering the new findings, some species previously labeled as “least concern” for conservation, stand now in some level of threat. This appraisal challenges the misperception of MLM as well-known and shows that taxonomy is a conservation issue.

Primer design of D-loop region for wild population genetics of Rusa timorensis in Indonesia

Rusa timorensis (Javan deer) is endemic wildlife in Indonesia and is estimated at less than 10.000 individuals with continuously declining populations due to habitat loss and illegal hunting in the wild. This declining low population indicates a greater risk of extinction. Unfortunately, the genetic information of the wild Javan deer population for conservation management strategies still lacks data due to challenging sampling in the wild. Most recent studies were analysing the breeding populations outside Indonesia. Here, we propose the primer design of the D-loop genetic marker to determine the genetic population of wild Javan deer. We used metadata analysis of genetic sequences and new samples from five wild populations to design the specific primer of the D-loop region of the wild Javan deer in Indonesia. We used software, i.e.., Primer3 to design the primers, BLAST for specificity and Oligo Analyzer™ Tool for efficiency of the primer. The Annealing temperature optimisation started with pre-denaturation at 94 °C followed by 35 cycles of denaturation at 95°C; 51-56°C annealing for each one degree’s different per PCR treatment; and 72°C extensions. We successfully designed a specific primer (RL-3.1a) to amplify 235 bp of the D-loop region at 52°C annealing’s temperature.

Assessing conservation priorities of endemic seed plants in the central Himalaya (Nepal): A complementarity and phylogenetic diversity approach

The rate of species extinction has accelerated in the past few decades due to human-induced global changes. Establishing protected areas (PA) is one of the most viable solutions to averting this crisis. Although PA establishment in the past followed an ad-hoc approach without considering the conservation value of the prioritized areas, the development of systematic conservation planning approaches has largely maximized the conservation output by offering low-cost and high-efficiency spatial solutions. However, the conservation initiatives are still biased towards mammals and birds and despite the essential ecological role of plants, they are hardly taken as a proxy for conservation decision-making. Furthermore, although phylogenetic diversity captures areas that offer greater ecosystem functions, it remains largely neglected in conservation practice. In this study, using a comprehensive distribution dataset of 316 endemic seed plants in the central Himalaya and the time-calibrated phylogeny, we identified key areas for the systematic protection of species and evolutionary diversity of endemic seed plants. We found a large gap in protecting endemic seed plants in the central Himalaya likely due to disproportionate location of PAs. We recommend expanding protected areas to the mid-hills and lowlands to ensure better representation of biodiversity in the central Himalayan PA network. While flagship species undeniably require high conservation focus, our findings suggest the need to reassess the conservation priorities of less charismatic species too, as many of these species are crucial to ecosystem health and are at greater risk of extinction.

Range restriction leads to narrower ecological niches and greater extinction risk in Australian freshwater fish

Range restriction leads to narrower ecological niches and greater extinction risk in Australian freshwater fish

Whole genome sequencing reveals high differentiation, low levels of genetic diversity and short runs of homozygosity among Swedish wels catfish

The use of genetic markers in the context of conservation is largely being outcompeted by whole-genome data. Comparative studies between the two are sparse, and the knowledge about potential effects of this methodology shift is limited. Here, we used whole-genome sequencing data to assess the genetic status of peripheral populations of the wels catfish (Silurus glanis), and discuss the results in light of a recent microsatellite study of the same populations. The Swedish populations of the wels catfish have suffered from severe declines during the last centuries and persists in only a few isolated water systems. Fragmented populations generally are at greater risk of extinction, for example due to loss of genetic diversity, and may thus require conservation actions. We sequenced individuals from the three remaining native populations (Båven, Emån, and Möckeln) and one reintroduced population of admixed origin (Helge å), and found that genetic diversity was highest in Emån but low overall, with strong differentiation among the populations. No signature of recent inbreeding was found, but a considerable number of short runs of homozygosity were present in all populations, likely linked to historically small population sizes and bottleneck events. Genetic substructure within any of the native populations was at best weak. Individuals from the admixed population Helge å shared most genetic ancestry with the Båven population (72%). Our results are largely in agreement with the microsatellite study, and stresses the need to protect these isolated populations at the northern edge of the distribution of the species.

Identification of plant micro-reserves using conservation units and population vulnerability: The case of an endangered endemic Snowflake (Acis nicaeensis) in the Mediterranean Basin hotspot

Erosion of natural habitats due to urban sprawl constitutes a major threat to biodiversity. The development of the Plant Micro-Reserve (PMR) is an efficient concept for the in situ conservation of rare plants with narrow ecological niche and threatened by human impacts. We provide a framework for initiating site selection of PMRs, including evolutionary and ecological uniqueness. The proposed cross-analysis is based on (i) the estimate of population vulnerability, (ii) the contribution of each population to the evolutionary originality of the species by designating conservation units, and (iii) the gap analysis of the current protection status of the populations. As a case study, we apply this framework to the Nice Snowflake Acis nicaeensis, a narrow Mediterranean endemic plant of the French-Italian Riviera which, being caught in the turmoil of urban sprawl, is threatened by tremendous anthropogenic pressures. On the basis of historical data (past land-use and herbarium data) we show that over the last 150 years, the impact of urbanization has been severe for 70 % of the populations and has caused the disappearance of at least 11 of them, i.e. 20 % of the known populations. Similar levels of urban sprawl are observed between the most vulnerable and already extinct populations. In this context of biodiversity decline, our cross-analysis highlights that two of the five conservation units call for a rapid setting up of PMRs because of their high originality and their great risk of extinction: one unit including the populations of the Principality of Monaco and one unit that includes the populations of Nice and its surroundings. This study demonstrates the importance of integrating population vulnerability and conservation units. In a context of huge urbanization our approach makes a clear case for the design of PMRs.

Anatomical study of Orchidaceae epiphytes species occurring in indigenous territory in the Parque Estadual da Serra do Tabuleiro (P.E.S.T.), Santa Catarina, Brazil

Abstract Besides their ecological importance, epiphytic species of Orchidaceae play economic and social roles through their commercialization and some are at great risk of extinction. The objectives of this study were to characterize the leaf and root anatomy of fourteen epiphytic Orchidaceae species, which occur in indigenous territory in the Parque Estadual da Serra do Tabuleiro (P.E.S.T.), Santa Catarina, Brazil and to identify adaptive anatomical characteristics related to the epiphytic habit. The species are commercialized by the Guarani and were collected during interviews and guided tours with Guarani in the indigenous territory. The results reveal the species have many morphoanatomical structures that are useful during water shortages resulting from the epiphytic habit. Notable characteristics are related to reserving water (i.e., pseudobulbs and a hypodermis with water-storage cells) and resistance to desiccation in the leaf (i.e., conspicuous cuticle, suprastomatic chamber and extraxylary and pericyclic fibers) and root (i.e., tilosomes and/or exodermal thickening and cortex cells with phi thickenings or sclereids). Descriptions and the identification of adaptive characteristics of epiphytic plant species are useful for conservation and cultivation studies, especially for plants commercially used by the Guarani Indians.

A threatened species index for Australian birds

AbstractQuantifying species population trends is crucial for monitoring progress towards global conservation targets, justifying investments, planning targeted responses and raising awareness about threatened species. Many global indicators are slow in response and report on common species, not on those at greatest risk of extinction. Here we develop a Threatened Species Index as a dynamic tool for tracking annual changes in Australia's imperiled birds. Based on the Living Planet Index method and containing more than 17,000 time series for 65 bird taxa surveyed systematically, the index at its second iteration shows an average reduction of 59% between 1985 and 2016, and 44% between 2000 and 2016. Decreases seem most severe for shorebirds and terrestrial birds and least severe for seabirds. The index provides a potential means for measuring performance against the Convention on Biological Diversity's Aichi Target 12, enabling governments, agencies and the public to observe changes in threatened species.

Automated conservation assessment of the orchid family with deep learning.

International Union for Conservation of Nature (IUCN) Red List assessments are essential for prioritizing conservation needs but are resource intensive and therefore available only for a fraction of global species richness. Automated conservation assessments based on digitally available geographic occurrence records can be a rapid alternative, but it is unclear how reliable these assessments are. We conducted automated conservation assessments for 13,910 species (47.3% of the known species in the family) of the diverse and globally distributed orchid family (Orchidaceae), for which most species (13,049) were previously unassessed by IUCN. We used a novel method based on a deep neural network (IUC-NN). We identified 4,342 orchid species (31.2% of the evaluated species) as possibly threatened with extinction (equivalent to IUCN categories critically endangered [CR], endangered [EN], or vulnerable [VU]) and Madagascar, East Africa, Southeast Asia, and several oceanic islands as priority areas for orchid conservation. Orchidaceae provided a model with which to test the sensitivity of automated assessment methods to problems with data availability, data quality, and geographic sampling bias. The IUC-NN identified possibly threatened species with an accuracy of 84.3%, with significantly lower geographic evaluation bias relative to the IUCN Red List and was robust even when data availability was low and there were geographic errors in the input data. Overall, our results demonstrate that automated assessments have an important role to play in identifying species at the greatest risk of extinction.

Functional traits of avian frugivores have shifted following species extinction and introduction in the Hawaiian Islands

Abstract The extinction and introduction of species can alter ecological processes owing to the loss or gain of species roles. In vertebrate‐dependent seed dispersal, mutualisms between frugivores and fruiting plants depend, in part, on matching of functional traits. High species turnover of frugivores has occurred on the Hawaiian Islands, owing to both the loss of native frugivores and the introduction of a new suite of frugivores. How this turnover has altered the functional traits of frugivores and the potential impacts on seed dispersal remain unclear. We investigated how avian frugivore traits differed between historic and modern assemblages of the Hawaiian Islands. We also tested how traits shifted within foraging guilds (ground vs. arboreal) to distinguish potential impacts on plants within low versus high forest strata. Compared to historic frugivores, the modern assemblage is smaller in gape width and body mass in both ground and arboreal guilds. Wing shape did not significantly change between assemblages. From the results, we postulate that changes in the frugivore community have likely altered seed dispersal processes by reducing (a) the size of seeds consumed, (b) frugivory rates per animal and (c) seed dispersal distances. Owing to seed size placing strong constraints on consumption, we reviewed recent studies on frugivory by modern birds in the Hawaiian Islands and compared the size of seeds consumed versus seeds available. We found that larger‐seeded plants (>8.1 mm seed width) were not consumed by modern birds and were more likely to be of conservation risk compared to smaller‐seeded plants. Consequently, dispersal limitation may threaten Hawaiian plant communities, with larger‐seeded plants at greatest risk of extinction. Broadly, we show that extensive turnover within assemblages may lead to significant changes in functional traits, with potential knock‐on effects for mutualistic interactions and communities. A free Plain Language Summary can be found within the Supporting Information of this article.

Effects of early thermal environment on the behavior and learning of a lizard with bimodal reproduction

Early developmental temperatures influence the physiology and behavior of reptiles, with important consequences for their fitness and survival. For example, many viviparous lizards are cold adapted which may restrict their activity times during the reproductive season, increasing their susceptibility to global warming. However, it is unclear if and how lizards with different reproductive modes (oviparity vs. viviparity) can respond to rising temperatures by modifying their life-history traits. We examined the effect of developmental temperatures on hatchling behavior and learning in viviparous and oviparous populations of the lizard Saiphos equalis to test whether their reproductive behavior can buffer against rising temperatures. Gravid females from both populations were subjected to current or projected end-of-century (future) thermal environments to evaluate differences in the exploratory, foraging and antipredator behavior, and spatial learning ability of their offspring. We found that viviparous lizards were more exploratory and had a less-pronounced antipredator response than oviparous lizards. Regardless of the mode of reproduction, elevated temperatures reduced the exploratory behavior of hatchling lizards. Elevated temperatures also reduced the foraging efficiency of oviparous, but not viviparous, hatchlings. Finally, future-gestated oviparous hatchlings were more likely to choose the correct refuge and made fewer mistakes in a spatial learning task; however, we found only weak evidence of spatial learning in S. equalis. Our results suggest that although global warming is likely to have a negative impact on phenotypic traits, in S. equalis, some of these effects may be ameliorated by maternal behavior and/or physiological responses during pregnancy, particularly in viviparous populations. Computational modeling studies suggest that live-bearing lizards (viviparous) are more vulnerable to global warming compared with egg-laying ones (oviparous). However, there is little experimental evidence showing that viviparous species are indeed at a greater risk of extinction. Using a lizard species that has both oviparous and viviparous populations, we tested the effect of high developmental temperatures (projected for 2100) on the behavior and learning of their offspring. We found that elevated temperatures had a stronger negative effect on egg-laying lizards by producing hatchlings with lower foraging efficiency. Our results suggest that viviparous mothers can ameliorate some of the effects of global warming on their offspring. Moreover, our study suggests that if live bearers are indeed more vulnerable to global warming, it is likely not due to maladaptive behavior in offspring, but rather, to other causes that affect pregnant females.

Species in peril: assessing the status of the trade in pangolins in Nepal

Pangolins are among the most widely traded taxa in the southeastern Asian illegal wildlife trade because of which they are at great risk of extinction. Yet, little is known of their trade status in Nepal. This research was carried out to unfold the status of pangolin trade in Sankhuwasava District of Nepal. We used mixed methods such as semi-structured questionnaire (n=75) and, focus group discussion (n=4) and key Informant Interview, (n=30) to assess the trade status. Seizure data (2009–2017) were gathered from law enforcement agencies to predict major trade routes. The major threat perceived was hunting especially by unemployed local youth and children. The majority of hunters were opportunistic. Sankhuwasava District has become both source and transit for the illegal pangolin trade rather than for local use. The involvement of non-timber forest product traders was high in the illegal trade business, however, there seems a rapid decline in the seizure of pangolin in the last two years, mainly because of the deployment of the Nepal army in the Makalu Barun National Park, which had long served as a major route to China. Thus, we recommend continuation of strong border security. Our study calls for capacity building of enforcement agencies for detailed investigation of seizure data. For sustainable conservation of pangolin and its habitat we recommend sustained conservation awareness programs in addition to alternative livelihood opportunity. Furthermore, formation of community based anti-poaching units followed by motivation, anti-poaching trainings, security assurance, and incentives for worthy conservation outcomes in pangolin-rich communities might aid in conservation.

Body size, sampling completeness, and extinction risk in the marine fossil record

AbstractLarger body size has long been assumed to correlate with greater risk of extinction, helping to shape body-size distributions across the tree of life, but a lack of comprehensive size data for fossil taxa has left this hypothesis untested for most higher taxa across the vast majority of evolutionary time. Here we assess the relationship between body size and extinction using a data set comprising the body sizes, stratigraphic ranges, and occurrence patterns of 9408 genera of fossil marine animals spanning eight Linnaean classes across the past 485 Myr. We find that preferential extinction of smaller-bodied genera within classes is substantially more common than expected due to chance and that there is little evidence for preferential extinction of larger-bodied genera. Using a capture–mark–recapture analysis, we find that this size bias of extinction persists even after accounting for a pervasive bias against the sampling of smaller-bodied genera within classes. The size bias in extinction also persists after including geographic range as an additional predictor of extinction, indicating that correlation between body size and geographic range does not provide a simple explanation for the association between size and extinction. Regardless of the underlying causes, the preferential extinction of smaller-bodied genera across many higher taxa and most of geologic time indicates that the selective loss of large-bodied animals is the exception, rather than the rule, in the evolution of marine animals.

Influence of Vitellaria Paradoxa Gaertn Depletion on the Incidence, Abundance and Distribution of Cirina Forda Westwood (Lepidoptera: Saturniidae) in Niger State, Nigeria

The pallid emperor moth, Cirina forda, is a prominent edible insect in Niger State but currently at great risk of extinction. The incidence, abundance and distribution of Cirina forda, was investigated for four consecutive seasons, i.e. May-June 2010, 2011, 2012 and 2013 to ascertain the effect of the depletion of its host plant, Shea butter trees, Vitellaria paradoxa. in Niger State, Nigeria. C. forda egg clusters located on the host plants were enumerated to ascertain the seasonal abundance by visual counting using hand lenses and binoculars (MARCO-model 750/8 m-988000 m). At each location, 100m2 land area in which three 10m2 portions were mapped as replicate sites, were investigated for host plant density, egg cluster abundance and distribution within three host plant canopy height ranges. The 41 locations in six Local Government Areas (LGAs) where C. forda occurred in Niger State in 2010 were investigated. The result indicated the GPS of each of the locations and showed that Niger state had a very rich but fast dwindling population of V. paradoxa. C. forda egg cluster abundance across the six LGAs showed Niger state as highly endowed but ephemeral and highly unpredictable, especially in terms of location where they occurred. The egg cluster abundance reduced drastically from 58.1± 12.1 and 56.1±24.1 egg cluster/host plant in 2010 and 2011, respectively to 41.3 ± 8.3 and 29.7 ±5.1 egg cluster/host plant in 2012 and 2013 cropping seasons, respectively. Locational similarities were observed in the trends of C. forda host plant density reduction and egg cluster abundance over the four cropping seasons and these were corroborated across the State. The decreasing densities of Shea butter trees was identified as posing serious threats to egg laying by C. forda. The possibility of the extinction of C. forda was identified as imminent and a conservation approach that stems the indiscriminate destruction of host tree, V. paradoxa (Shea butter trees) was proposed.

New species, diversity, systematics, and conservation assessment of the Puppet Toads of Sumatra (Anura: Bufonidae: Sigalegalephrynus).

Using a combination of morphological and molecular data we recognize three new species of Puppet Toad, Sigalegalephrynus Smart, Sarker, Arifin, Harvey, Sidik, Hamidy, Kurniawan Smith, a recently described genus endemic to the highland forests of Sumatra, Indonesia. Phylogenetic analysis of mitochondrial DNA sequences recovered a monophyletic relationship among all Puppet Toads, with two distinct evolutionary clades, a northern and a southern. The northern clade includes Sigalegalephrynus gayoluesensis sp. nov., and S. burnitelongensis sp. nov., and the southern clade includes S. harveyi sp. nov., S. mandailinguensis, and S. minangkabauensis. With the discovery of these three new species, Sigalegalephrynus contains more endemic species than any other genus of toad in Indonesia. We used maximum entropy, implemented in MaxEnt, to identify suitable habitats and occurrence probability of additional undescribed new species from the island. The most important predictors of Sigalegalephrynus distribution were elevation (64.5%) and land cover (7.11%). Based on the probability of presence, it is likely that there are many more species of the genus awaiting discovery in Sumatra. Our analysis, based on IUCN Red List of Threatened Species category and criteria, shows that all of the five species of Sigalegalephrynus are in great risk of extinction and should be placed into the Endangered (EN) category of IUCN Red List.

Spatial niche modelling of five endemic cacti from the Brazilian Caatinga: Past, present and future

AbstractClimate change, together with human activities, impacts on natural and human systems on all continents and poses a major threat to biodiversity, especially in environments with a high rate of endemism and where species are profoundly adapted to specific environmental conditions, as is the case of the seasonally dry tropical forests, noticeably the Caatinga, an exclusively Brazilian biome. The objective of this study was to build spatial niche models of five species of Cactaceae (Arrojadoa penicillata, Brasilicereus phaeacanthus, Pereskia aureiflora, Stephanocereus leucostele and Tacinga inamoena) endemic to the Caatinga and with different traits, to evaluate the impact of climate change on their geographical distribution. The species records and environmental variable values were overlaid on a grid of 6818 cells with 0.5° spatial resolution. Niche models were obtained for five types of general circulation models between ocean and atmosphere and 12 different ecological models. The ensemble ecological niche model was calculated at present and projected to past (last glacial maximum – LGM, 21 000; and mid‐Holocene – Hol, 6000 years ago) and future climate conditions (average of 2080), under the effect of climate change, in the greenhouse gas emission scenario RCP4.5. The distribution pattern of the studied species indicates an area with less environmental suitability in the LGM, followed by an expansion that began in the Hol and continued until the present period. In the future (2080), the models predicted a retraction of areas of environmental suitability, in which P. aureiflora and B. phaeacanthus, given their more restricted, marginal habitat and woody habit, present a great risk of extinction, whilst S. leucostele, A. penicillata and T. inamoena present a smaller reduction in suitable area, partly reflecting their spreading, less woody habit. Regional conservation actions for Cactaceae species and their habitat need to take these findings into account if we are to ensure the survival of these species.

Genomic variation predicts adaptive evolutionary responses better than population bottleneck history.

The relationship between population size, inbreeding, loss of genetic variation and evolutionary potential of fitness traits is still unresolved, and large-scale empirical studies testing theoretical expectations are surprisingly scarce. Here we present a highly replicated experimental evolution setup with 120 lines of Drosophila melanogaster having experienced inbreeding caused by low population size for a variable number of generations. Genetic variation in inbred lines and in outbred control lines was assessed by genotyping-by-sequencing (GBS) of pooled samples consisting of 15 males per line. All lines were reared on a novel stressful medium for 10 generations during which body mass, productivity, and extinctions were scored in each generation. In addition, we investigated egg-to-adult viability in the benign and the stressful environments before and after rearing at the stressful conditions for 10 generations. We found strong positive correlations between levels of genetic variation and evolutionary response in all investigated traits, and showed that genomic variation was more informative in predicting evolutionary responses than population history reflected by expected inbreeding levels. We also found that lines with lower genetic diversity were at greater risk of extinction. For viability, the results suggested a trade-off in the costs of adapting to the stressful environments when tested in a benign environment. This work presents convincing support for long-standing evolutionary theory, and it provides novel insights into the association between genetic variation and evolutionary capacity in a gradient of diversity rather than dichotomous inbred/outbred groups.

Diversity loss is predicted to increase extinction risk of specialist animals by constraining their ability to expand niche

Specialist animals are at a greater risk of extinction in the face of environmental change than generalist ones. The inability of some specialist taxa to expand host range through evolution may exacerbate or cause their high extinction risk. Here we use connectionism (a framework for modelling animal behaviour) to predict the environmental and physiological factors that predispose some specialist taxa to an ‘evolutionary dead-end’. Neural networks are evolved to become resource-specialised in a resource-abundant and resource-diverse ‘historical’ environment while losing ‘genes’ that should restrict their ability to expand their host range. Networks are subsequently challenged to escape their dead-end by expanding host range in a ‘contemporary’ environment that may have depleted resource abundance and diversity (as many human impacted environments do). Loss of diversity in available resources universally constrains the ability of networks to expand host range and this effect is very robust to network conformation. Environmental resource abundance is more variable in its effect. Networks are generally robust to loss of genetic diversity during the evolution of specialisation except at very high rates of loss. By omitting historical specialisation, we show that the effect of resource diversity on host range expansion is not a universal network property but something that is often specific to specialist organisms. Historical specialisation also slightly reduces the robustness of networks in the contemporary environment to loss of genetic diversity during the specialisation process. Fundamentally, simulations predict that loss of local resource diversity will further increase the vulnerability of specialists to extinction by constraining their ability to expand host range in the face of environmental change.

Amphibians

Since the dawn of history, amphibians have been a part of human culture. Western Europeans built fires for cooking and warmth, adding large logs as needed. What occasionally emerged was astounding: large black animals (which had found shelter in the logs) with four legs and a tail, jet black with striking bright yellow spots. These fire salamanders were variously thought to be the product of the fire itself, or, as Aristotle reported, capable of extinguishing fire. Pliny the Elder is said to have tested this idea by throwing a salamander into flames - the salamander died! - nevertheless the association with fire persisted. Pliny perpetuated other fantastical claims, which spread; even Leonardo da Vinci contributed to the legend, and myths from different regions merged - at one point, asbestos was claimed to be salamander wool. Salamanders were attributed great powers; a single salamander upstream was thought to be sufficient to kill an army. King Francis I. of France chose a salamander as his emblem - a powerful symbol, born of fire, filled with poison, immune from burning, and even able to douse flames. Before the emergence of great cities and conurbations, people grew up surrounded by nature. Salamanders and newts, toads and frogs were all part of normal human experience. Myths such as those surrounding the fire salamanders were commonplace. Shakespeare's witches brewed with an eye of newt and tail of frog. As a child, we raised tadpoles and were taught to shudder at the appearance of a tiger salamander in a root cellar. In general, amphibians are seen as benign and harmless, even helpful as creatures that devour harmful insects and serve as an alternative food source. Thus, it came as a shock to most biologists and to the public at large in the 1980s that amphibians around the world were in decline and that they were at greater risk of extinction as a taxon than any other vertebrate group. A study of every amphibian species known in 2004 showed that on the order of 40% were at high risk of extinction, and by 2008, the decline of amphibians was seen as evidence of an impending sixth mass extinction.

Additive negative effects of Philornis nest parasitism on small and declining Neotropical bird populations

SummaryThe declining-population paradigm holds that small populations are particularly vulnerable to anthropogenic influences such as habitat destruction, pollution and species introductions. While the effects of particular stressors, such as parasitism, may be unimportant in a large, healthy population, they can be serious and even devastating in situations characterised by a restricted geographic range, or by fragmented or reduced population sizes. We apply this idea to nest parasitism of threatened Neotropical bird species that exist in small populations, focusing on dipteran nest parasites in the genusPhilornis. We review the literature onPhilornisparasitism exerting negative pressure on bird populations that have become small and isolated due to human actions and present a new case ofPhilornisparasitism of a threatened hummingbird species. Our aim is to raise awareness about the exacerbating effect that nest parasites can have on small and declining bird populations; especially when biological information is scarce. The five reviewed cases involve two species of Darwin’s Finches in the Galápagos Islands attacked by the invasiveP. downsi, two species of hawks on islands in the Caribbean attacked by the nativeP. piciandP. obscura, and the Yellow CardinalGubernatrix cristatain southern South America attacked by an unknownPhilornisspecies. We also present new documentation of parasitism of a threatened hummingbird species in mainland Ecuador by an unidentifiedPhilornisspecies. We recommend more field studies to determine the presence of nest parasites in bird populations worldwide to improve understanding how nest parasites affect bird fitness and population viability and to allow time to act in advance if needed. Parasitism byPhilornismay represent a severe mortality factor in most already threatened bird species, putting them at greater risk of extinction. Therefore, parasitism management should be included in all threatened species recovery plans.