Applying IUCN criteria to invertebrates: How red is the Red List of European butterflies?

The IUCN is the leading authority on assessing species’ extinction risks worldwide and introduced the use of quantitative criteria for the compilation of Red Lists of threatened species. Recently, we assessed the threat status of the 483 European butterfly species, using semi-quantitative data on changes in distribution and in population sizes provided by national butterfly experts. We corrected distribution trends for the observation that coarse-scale grid cells underestimate actual population trends by 35%. To account for uncertainty, we included a 5% error margin on the distribution and population trends provided. The new Red List of European butterflies determined one species as Regionally Extinct, 37 species as threatened (Critically Endangered, Endangered or Vulnerable) and a further 44 as Near Threatened. The use of semi-quantitative data on distribution and population trends permitted us to use IUCN criteria to compile a scientifically underpinned Red List of butterflies in Europe. However, a comparison of detailed monitoring data for some grassland species showed that coarse-scale grid cell data and population trends strongly underestimate extinction risks, and the list should be taken as a conservative estimate of threat. Finally, combining the new Red List status with the data provided by the national butterfly experts, allowed us to determine simple criteria to delineate conservation priorities for butterflies in Europe, so called SPecies of European conservation Concern (SPEC’s). Using European butterflies, our approach illustrated how Red Listing can be performed when data are incomplete for some IUCN criteria or vary strongly among countries.     

Using remote sensing to inform conservation status assessment: Estimates of recent deforestation rates on New Britain and the impacts upon endemic birds

Remote sensing is increasingly used by policy-makers and conservationists to identify conservation priorities and changes in land cover. This is particularly important in the biodiverse tropics, where there are often few field data. Conservation action is often directed towards areas containing globally threatened species, but there have been few attempts to improve assessments of species’ extinction risk through remote sensing. Here, in a novel approach we use deforestation estimates, measured through satellite imagery, to assess the conservation status of an entire endemic avifauna, based on IUCN Red List criteria. The island of New Britain, east of New Guinea, is of very high global conservation importance, and home to 37 endemic or restricted-range bird species. Analysis suggests 12% of forest cover was lost between 1989 and 2000, including over 20% of forest under 100 m altitude, with substantial areas cleared for commercial oil palm plantations. Application of the IUCN Red List criteria to these new data on area of remaining forest and rates of deforestation indicates that many species are more threatened than previously realised, with the total number of threatened or near threatened species increasing from 12 to 21. Thus, this study highlights the urgency of establishing and effectively managing protected areas in suitable lowland forests of New Britain. More broadly, it demonstrates another potential of remote sensing to assist strategic conservation decisions.     

Data Deficient birds on the IUCN Red List: What don’t we know and why does it matter?

Species are classified as Data Deficient on the IUCN Red List if there is inadequate information to make an assessment of their extinction risk based on distribution and/or population status. Data Deficient is probably the most controversial and misunderstood of IUCN Red List categories. All 63 globally Data Deficient bird species lack sufficient information on population size, trends, distribution and/or threats to assess them against the Red List criteria. For 10 species (16%) the paucity of data may be a consequence of taxonomic uncertainty. Three species are known only from specimens of uncertain geographic provenance. Since 1988, 58 Data Deficient birds have been recategorised, mainly as Near Threatened (48%) or Least Concern (16%). We speculate that of the remaining Data Deficient birds, just 14% may prove to be threatened. Proportionately fewer birds (0.6%) are listed as Data Deficient as compared with mammals (15%), amphibians (25%), corals (17%), conifers (4%) and cycads (6%), because birds are better known and perhaps because for birds greater use is made of contextual information (e.g. condition of habitats, likely ecology/habitat preferences and trends in known threatening processes) to assign alternative categories where this is plausible and precautionary. Ensuring consistency between taxonomic groups is essential for the credibility of the IUCN Red List. For non-avian taxa, the higher proportions of Data Deficient species introduces greater uncertainty in estimates of overall extinction risk, but the results from birds hint that the real values may fall at the lower end of these estimates. Data Deficient species should be treated precautionarily in terms of protection and assessing environmental impacts, and regarded as urgent priorities for surveys and research to elucidate their true status. Greater attention should also be given to documenting data quality and uncertainty for Red List assessments of threatened and non-threatened species.     

How similar are national red lists and the IUCN Red List?

For more than four decades the International Union for the Conservation of Nature (IUCN) has been assessing the global threat status for species and publishing the results in the periodically updated IUCN Red List of threatened species. Additionally, numerous countries have published national lists of threatened species, often based on IUCN criteria and guidelines for application of IUCN Red List criteria at regional levels. To assess how similar, or how different, national red lists are from the global red list, we compared threatened species lists of four countries (Brazil, Colombia, China, and the Philippines) with the 2008 IUCN Red List. We found notable differences falling into three categories: (1) a number of species (an average of 20% of the species pool considered in each of the four countries) have been listed nationally as threatened, but have yet to be globally assessed by IUCN, (2) some species (14% average) are considered globally threatened by IUCN, but are not listed nationally, and (3) a handful of species (2% average) are not considered threatened by IUCN, but are nationally threatened. However, for most species, the threat assessments concur. In other words, most species are either considered threatened both nationally and globally, or else not considered globally threatened and not listed nationally. Such possible comparison between national red lists and IUCN’s Red List is a high priority both for IUCN and for national red listing agencies.     

Odonata enter the biodiversity crisis debate: The first global assessment of an insect group

The status and trends of global biodiversity are often measured with a bias towards datasets limited to terrestrial vertebrates. The first global assessment of an insect order (Odonata) provides new context to the ongoing discussion of current biodiversity loss. A randomly selected sample of 1500 (26.4%) of the 5680 described dragonflies and damselflies was assessed using IUCN’s Red List criteria. Distribution maps for each species were created and species were assigned to habitat types. These data were analysed in respect to threat level for regions and habitat types. We have found that one in 10 species of dragonflies and damselflies is threatened with extinction. This threat level is among the lowest of groups that have been assessed to date, suggesting that previous estimates of extinction risk for insects might be misleading. However, Odonata only comprise a small invertebrate order, with above-average dispersal ability and relatively wide distribution ranges. For conservation science and policy to be truly representative of global biodiversity a representative cross-section of invertebrates needs to be included.     

Earthworm (Lumbricidae) diversity in the Central Balkans: An evaluation of their conservation status

In this paper we summarize the current knowledge on earthworm diversity in the central part of the Balkans, in the State of Serbia. Up to now, 71 species and 8 subspecies, belonging to 18 genera, are known from investigated territory. Our aim was to produce a single priority list for earthworm conservation, particularly as the Balkan countries did not have their own Red Lists for earthworms and none of the species had a legally protected status. The list underlines the diversity of earthworms, zoogeographical position as well as category of threat. The analysis based on the IUCN (2001) Red List Categories shows that 17 of 79 taxa are Critically Endangered (5 species are serious Critically Endangered, but 12 species are only suspect for the Critically Endangered category), 9 species are Endangered and 14 species are Vulnerable. Serious candidates for their inclusion in CR category within the IUCN (2001) Red List are: Cernosvitovia biserialis, Dendrobaena kozuvensis, Lumbricus improvisus, Serbiona kosowensis montenegrina and Serbiona serbica. Of all registered earthworms, 34 taxa (43.1%) were identified only as endemic species. Unfortunately, most of the high-priority species are endemic (23 taxa). The position of the Central Balkans contributes to the great biodiversity of earthworms on its territory, but the fact that nearly 36% of its lumbricids are threatened is a strong signal that action is required.     

Freshwater crabs and the biodiversity crisis: Importance, threats, status, and conservation challenges

Freshwater ecosystems in the tropics host a diverse endemic fauna including freshwater crabs, but the rapid loss and deterioration of habitat means that many species are now under imminent threat. Studies on freshwater fish and amphibians suggest a third to half of the species in some tropical freshwaters is either extinct or endangered, but the status of the freshwater crabs is not known. Freshwater crabs, with 1280 species, represent one-fifth of all the World’s brachyurans. We therefore undertook a comprehensive IUCN Red List assessment of the freshwater crabs, which was the first time that such a study had been attempted on a global scale for any group of freshwater invertebrates. The conservation status of all known species from the Americas, Africa, Europe, Asia, and Australasia revealed unexpectedly high threat levels. Here we show that about one-sixth of all freshwater crab species have an elevated risk of extinction, only one-third are not at-risk, and although none are actually extinct, almost half are too poorly known to assess. Out of 122 countries that have populations of freshwater crabs, 43 have species in need of protection. The majority of threatened species are restricted-range semi-terrestrial endemics living in habitats subjected to deforestation, alteration of drainage patterns, and pollution. This is illustrated with a case study of one such species found in Singapore. This underlines the need to prioritize and develop conservation measures before species decline to levels from which they cannot recover. The proportion of freshwater crabs threatened with extinction is equal to that of reef-building corals, and exceeds that of all other groups that have been assessed except for amphibians. These results represent a baseline that can be used to design strategies to save the World’s threatened freshwater crab species.     

Conservation implications of deforestation across an elevational gradient in the Eastern Arc Mountains, Tanzania

Deforestation is a major threat to the conservation of biodiversity, especially within global centers of endemism for plants and animals. Elevation, the major environmental gradient in mountain regions of the world, produces a rapid turnover of species, where some species may exist only in narrow elevational ranges. We use newly compiled datasets to assess the conservation impact of deforestation on threatened trees across an elevational gradient within the Eastern Arc Mountains of Tanzania. The Eastern Arc has suffered an estimated 80% total loss in historical forest area and has lost 25% of forest area since 1955. Forest loss has not been even across all elevations. The upper montane zone (>1800 m) has lost 52% of its paleoecological forest area, 6% since 1955. Conversely, the submontane habitat (800–1200 m) has lost close to 93% of its paleoecological extent, 57% since 1955. A list of 123 narrowly endemic Tanzanian Eastern Arc tree taxa with defined and restricted elevational ranges was compiled and analyzed in regard to mountain block locations, elevational range, and area of forest within each 100 m elevational band. Half of these taxa have lost more than 90% of paleoecological forest habitat in their elevational range. When elevational range is considered, 98 (80%) of these endemic forest trees should have their level of extinction threat elevated on the IUCN Red List. Conservation efforts in montane hotspots need to consider the extent of habitat changes both within and across elevations and target conservation and restoration efforts throughout these ecosystems’ entire elevational ranges.     

Gaps in the protected area network for threatened Afrotropical birds

Protected areas established for wildlife conservation (IUCN category I-VI protected areas) or for forest and watershed conservation (forest reserves) across mainland sub-Saharan Africa have high biodiversity values. However, they fail to cover over half of the 106 threatened bird species, and thus leave these vulnerable to extinction. An analysis of Red List bird species that are not represented in existing reserves indicates gaps in the current network of protected areas, namely: Mt. Cameroon-Bamenda highlands (Cameroon), the Angolan scarp (Angola), the Drakensberg Highlands (South Africa), the Highveld (South Africa), the Eastern Arc Mountains (Tanzania), the eastern African coastal forest mosaic (Kenya and Tanzania), the Albertine Rift (Uganda, Rwanda, Burundi, eastern Democratic Republic of Congo and western Tanzania), and the Ethiopian Highlands. The addition of Forest Reserves to the existing protected areas closes some of the reservation gaps for threatened birds in Africa. We suggest that these Forest Reserves should be included within official lists of protected areas, and that National forestry authorities be encouraged to manage these areas. Publication of scientific articles showing the conservation value of Forest Reserves is needed to raise local and international support and funding.     

Adapting global biodiversity indicators to the national scale: A Red List Index for Australian birds

The Red List Index (RLI), which uses information from the IUCN Red List to track trends in the projected overall extinction risk of sets of species, is among the indicators adopted by the world’s governments to assess performance under the Convention on Biological Diversity and the United Nations Millennium Development Goals. For greatest impact, such indicators need to be measured and used at a national scale as well as globally. We present the first application of the RLI based on assessments of extinction risk at the national scale using IUCN’s recommended methods, evaluating trends in the status of Australian birds for 1990–2010. We calculated RLIs based on the number of taxa in each Red List category and the number that changed categories between assessments in 1990, 2000 and 2010 as a result of genuine improvement or deterioration in status. A novel comparison between trends at the species and ultrataxon (subspecies or monotypic species) level showed that these were remarkably similar, suggesting that current global RLI trends at the species level may also be a useful surrogate for tracking losses in genetic diversity at this scale, for which no global measures currently exist. The RLI for Australia is declining faster than global rates when migratory shorebirds and seabirds are included, but not when changes resulting from threats in Australia alone are considered. The RLI of oceanic island taxa has declined faster than those on the continent or on continental islands. There were also differences in the performance of different jurisdictions within Australia.     

A review of the conservation threats to carnivorous plants

Over half of the carnivorous plant species assessed by the International Union for the Conservation of Nature (IUCN) are listed as threatened (i.e. vulnerable, endangered, or critically endangered), but the threats to carnivorous plants have not previously been quantified systematically. In this review, we quantify the conservation threats to carnivorous plant taxa worldwide. Using the IUCN Red List, a literature search of Web of Knowledge, and the National Red Lists database, we collected data on the threats to 48 species of carnivorous plants from nine genera. The most common threat was habitat loss from agriculture, followed by the collection of wild plants, pollution, and natural systems modifications. A principal coordinate analysis revealed that species within a genus often faced similar threats, and an indicator species analysis found positive associations among species in the genus Sarracenia and agricultural activities, over-collection, invasive species, and pollution. Future research should further quantify the effects of pollution on carnivorous plants, and more thoroughly examine the potential role of carnivorous plants as indicator species for wetland health. More research is also needed to quantify the extinction risk for many carnivorous plants, as presently only around 17% of species have been assessed by the IUCN. Ensuring the conservation of carnivorous plants will help maintain the important ecosystem services they provide and prevent secondary extinctions of specialist species that rely on them.     

Reserve selection using Red Listed taxa in three global biodiversity hotspots: Dragonflies in South Africa

The Red List can be used a gauging tool by conservationists to assess which species require focused conservation attention. Mapping the relative distributions of species, and identification of centers of richness, endemism and threat are a first step towards site-oriented conservation action. We use here a specially developed biodiversity index, based on three weighted sub-components assigned to each species: geographical distribution, Red List status, and sensitivity to habitat change. We test this approach using what is called here the Dragonfly Biotic Index (DBI) to prioritize sites for conservation action, with special emphasis on species occurrence in three global hotspots in southern Africa. Using a selected set of the 23 top prioritized sites, we compare the DBI’s performance to that of a rarity-complementarity algorithm. As with several other taxa, local endemism levels are highest in the Cape Floristic Region (CFR), while richness is highest in the north east, particularly in the stream systems of the Maputaland-Pondoland-Albany (MPA) hotspot. Red Listed Odonata species are also concentrated in the CFR, while richness is highest in the MPA hotspot. Site prioritization using the DBI reveals that CFR sites protect Red Listed taxa rather well, despite the fact that catchments are only partially protected. The DBI demonstrates high levels of redundancy in representing Red Listed species, in other words, the same species are represented in several catchments. The value in the DBI thus lies in maximizing redundancy (i.e. representation) of globally Red Listed species. The rarity-complementarity algorithm represents all species, but without greater emphasis on the rare and threatened (i.e. Red Listed) species. We conclude that the DBI is of great value in selecting biodiversity hotspots, while the algorithm is useful for selecting complementarity hotspots. We identify protection gaps and thus recommend continued searches in centers of endemism and existing reserves, as well as gap areas. These searches will hone Red List assessments and identify priority sites, as well as monitor already-identified sites for changes in quality of habitat.     

Estimating population size in the subdesert mesite (Monias benschi): new methods and implications for conservation

The subdesert mesite, a terrestrial non-passerine bird endemic to the Mikea Forest of southwest Madagascar, is currently classified as globally threatened (category: Vulnerable). However, accurate assessment of threat in accordance with the IUCN Red List criteria (A, B and C) requires data on effective population size, area of habitat occupied and rate of decline, none of which is available for this species. Here we present the first empirical estimates of its population size using five complementary methods, three incorporating data on territory size and two using data gathered during call-playback surveys conducted throughout its entire global range. Estimates vary from 98,000 to 152,000 individuals, with the most reliable possibly being that generated by distance sampling (115,000). This figure is more than an order of magnitude greater than the only published estimate of <10,000 individuals. By analysing data on forest cover change, we estimate the population of the subdesert mesite to have declined by, at most, 10% in three generations. Although the rate of deforestation in 1994-1999 is double that calculated for 1962-1994, it is deemed unlikely that the population will decline by 20% over the next three generations. As such the species fails to meet criterion A. Although the subdesert mesite's range and area of occupancy are small, they are not fragmented and do not comprise fewer than 10 locations. Consequently, this species does not meet criterion B. Further, the species fails to meet criterion C, for which a maximum of 10,000 mature adults is required. According to IUCN (2000 Red List of Threatened Species) this species should therefore be downlisted in status. We discuss why it still warrants conservation attention and suggest the need for modifications to the criteria thresholds in relation to basic information about the ecology and taxonomic distinctness of species.     

Red List assessment of nine <Emphasis Type="Italic">Aegilops</Emphasis> species in Armenia

The aims of this study are to determine the geographical and ecological distribution of nine Aegilops species in Republic of Armenia and to make an assessment of their IUCN Red List status, using the IUCN Red list categories and criteria, in order to develop an in situ conservation strategy for wild relatives of wheat in Armenia. Ecogeographic surveys of nine Aegilops species were undertaken over 2 years in Armenia. They included a herbarium survey followed by extensive ground-truthing field surveys where targeted Aegilops species occur. The study showed that of the nine Aegilops species studied, four are threatened and of these, Ae. mutica and Ae. crassa are critically endangered. The latter species may even be extinct in Armenia. Ae. neglecta and A. biuncialis are endangered. Additional studies are required to assess the threat status of Ae. umbellulata. Ae. columnaris was assessed as near threatened, while the remaining species (Ae. triuncialis, Ae. cylindrica and Ae. tauschii) are of least concern. There has been a dramatic decline in the genetic resources of Aegilops species during recent years in Armenia as a result of adverse human impacts such as expansion of agriculture, urbanization and uncontrolled grazing. Several species, especially Ae. mutica and Ae. crassa, should be prioritized in conservation activities in Armenia. Efforts should be made to conserve genetic diversity of crop wild relative species both in situ and ex situ, bearing in mind that their germplasm carries potentially valuable information (traits) that can improve adaptability and productivity of cultivated wheat varieties.     

Threatened deer of the world: Conservation status

IUCN is launching a programme for the study and management of Cervidae threatened with extinction throughout their world range. The objectives are to improve the status of the deer by more effective management, and to stimulate and provide experience in sustained scientific and governmental involvement in threatened taxa. This paper reviews and analyses the conservation status of the threatened deer. It provides the basis for a second paper which it is hoped to publish shortly and which will described a research programme that has been designed to provide data to guide conservation practices.     

Correlates of extinction risk and hunting pressure in gamebirds (Galliformes)

The 284 species of Galliformes are a highly threatened group of birds subject to direct exploitation for food, sport and cultural practices. The impact of hunting is often assumed to contribute to the high percentage of species (26.4%) listed as threatened with extinction in the IUCN Red List. We take a macroecological approach to examine the anthropogenic and ecological correlates of extinction risk and hunting pressure using linear and stepwise regression. Independent contrasts are analysed, as well as raw species data, to control for the potential confounding influence of phylogenetic trends. Extinction risk is found to be predicted both by the ecological factors considered (e.g., latitudinal range, body mass, elevational range, habitat use) and secondarily by human factors (e.g., human population density, total calorie intake, composition of diet). Hunting pressure itself is also predicted well for the threatened species by several of the anthropogenic and ecological variables. The study demonstrates that human variables can be used successfully to predict extinction risk, and represent an improvement upon methods which examine ecological variables alone. Furthermore, we show that individual threats can be explored using similar techniques, providing a more detailed insight into the processes leading to extinction. As applied to the Galliformes, both approaches provide evidence supporting the hypothesis that hunting pressure has contributed to the high proportion of threatened species in this group, and thus reinforce the case for urgent measures to reduce the impacts of direct exploitation upon these birds.     

Rare and vulnerable birds in South Africa

The paper summaries information obtained through an initial survey undertaken to identify those avian populations which qualify for inclusion in a South African Red Data Book, and whose conservation status is in need of special attention. One hundred and one species' populations are included in the preliminary list. Nine of the 101 species are endemic to South Africa. There is a predominance of forest and wetland species, of birds of prey, and of mainly tropical species occurring as intrusions in the north east of South Africa. Many of the species listed are peripheral to South Africa and are widespread and abundant extra-limitally. Twenty species' populations which require urgent conservation attention are listed. As far as is known, no avian species has become extinct during historical times in South Africa, but two are at present endangered, i.e. threatened with immediate extinction.     

The influence of uncertainty on conservation assessments: Australian frogs as a case study

We evaluated the influence of uncertainty, based on variation in expert opinion, on assessment of conservation status of Australian amphibians. We examined relationships between different biological variables and inferred relative extinction risk, the influence of uncertainty on resulting ranks, and regional patterns of extinction risk and uncertainty. Our results were in general agreement with the International Union for the Conservation of Nature and Natural Resources but also reveal apparent high extinction risks among some taxa that the IUCN did not classify in any threatened category. These differences were exaggerated when the most conservative status assessments were taken from variation in expert opinion. Our assessments of relative extinction risk were strongly dependent on basic demographic variables, particularly population size, geographic distribution of populations and age at first reproduction. We identified regional hotspots of high relative extinction risk and poor knowledge of amphibians, leading to high uncertainty about the conservation status of species from those areas. Regional clustering of species with high relative extinction risk and high uncertainty may indicate higher levels of relative extinction risk than previously assessed. Our results highlight the influence of uncertainty on interpretation of conservation assessments of organism groups with large knowledge gaps. Uncertainty should be further incorporated into conservation planning as it not only highlights taxa with potentially underestimated extinction risk, but also facilitates identification of knowledge gaps informative of conservation status. Knowledge of regional patterns of extinction risk and uncertainty assists conservation planning through identification of regions of high extinction risk and/or large knowledge gaps.     

Conservation cornerstones: Capitalising on the endeavours of long-term monitoring projects

Ecological monitoring is widely used to measure change through time in ecosystems. The current extinction crisis has resulted in a wealth of monitoring programs focussed on tracking the status of threatened species, and the perceived importance of monitoring has seen it become the cornerstone of many biodiversity conservation programs. However, many monitoring programs fail to produce useful outcomes due to inherent flaws. Here we use a monitoring program from south-eastern Australia as a case study to illustrate the potential of such endeavours. The threatened carnivorous marsupial, the brush-tailed phascogale (Phascogale tapoatafa), has been monitored at various locations between 2000 and 2010. We present strong evidence for a decline in relative abundance during this period, and also describe relationships with environmental variables. These results provide insights likely to be valuable in guiding future management of the species. In the absence of the monitoring program, informed management would not be possible. While early detection of population declines is important, knowledge of the processes driving such declines is required for effective intervention. We argue that monitoring programs will be most effective as a tool for enhanced conservation management if they test specific hypotheses relating to changes in population trajectories. Greater emphasis should be placed on rigorous statistical analysis of monitoring datasets in order to capitalise on the resources devoted to monitoring activities. Many datasets are likely to exist for which careful analysis of results would have benefits for determining management directions.     

Inferring extinction from biological records: Were we too quick to write off Miss Waldron’s Red Colobus Monkey (Piliocolobus badius waldronae)?

We are now entering a time of immense environmental upheaval where experts are increasingly required to provide conservation assessments. Quantitative assessment of trends in species’ range and abundance is costly, requiring extensive field studies over a long period of time. For many species in dense habitats, it may be very difficult to establish reliable and sensitive survey and monitoring techniques, which are able to warn of potentially catastrophic population declines. Unfortunately many other species are only known through a few ‘chance’ sightings or a handful of museum specimens and therefore extinction may be even harder to ascertain. In 2000 Miss Waldron’s Red Colobus, Piliocolobus badius waldronae, was reported as extinct, but since then (in 2001) a single specimen has been collected. Four probabilistic methods were used to infer extinction based on a record of sightings of the subspecies. Based on the date when the extinction statement of Miss Waldron’s Red Colobus was made, all four methods returned probability values >0.05, suggesting that the subspecies is extant, but is extremely rare. If we cannot successfully monitor populations of critically endangered taxa, it becomes almost impossible to predict their extinction with any certainty and we can expect increasing numbers of false alarms in future years, which may undermine the potential for conservation action and, more worryingly, public support for conservation.