IUCN study identifies climate change resilient tree species in Indonesia that support threatened East Bornean orangutan populations, recommending their use in. Available for download as a PDF. A Preliminary List of Rare Mammals Including Those Believed to be Rare but Concerning Which Detailed Information is Still. Tables 1 & 2: Threatened species in past and present IUCN Red Lists Table 7 ( ) - Species changing IUCN Red List Category between and.
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Species, was produced to mark the 50th anniversary of the. Red List. The magazine was published in French with an. English pdf version available to download. “The IUCN Red List is a wake-up call, reminding us that our natural one of the indicators for the Millennium There are eight IUCN Red List Categories. Citation: IUCN Red List Committee. The IUCN Red List of Threatened Species™ Strategic. Plan - Version Prepared by the IUCN Red List.
For each Red List update, IUCN provides summaries of the numbers of species in each category, by taxonomic group and by country. To download the Summary Statistics Tables, click here. All of the statistics presented in the summary tables are for species only i. In order to monitor the changing status of biodiversity, it is essential to reassess species periodically. This reassessment may result in species moving into a different Red List Category for non-genuine or genuine reasons:.
Cardoso et al. Thus widespread and common species, with large population sizes and ranges, can qualify as being threatened with extinction on Red Lists if they are undergoing rapid decline.
Criterion A is justified because even large populations would eventually be driven to extinction by continuing decline Mace et al.
Allee effects, genetic inbreeding , but also because the reduction in abundance of common and widespread species may be of particular significance to ecosystem structure and functioning Gaston and Fuller ; Winfree et al.
However, the reliable measurement of species population trends that indicate extinction risk and are being driven by anthropogenic processes such as habitat loss or climate change for use in Red List Criterion A is made difficult by imperfect sampling observation errors and short-term stochastic variation in population levels caused by environmental variability process errors Connors et al.
Inaccurate detection of underlying species population trends can result in incorrect Red List classification false positives i. Investigations, using both empirical and simulated data, show that as process errors and observation errors increase, the reliable detection of population declines decreases across a range of different statistical techniques Wilson et al. Trends assessed over short time periods, such as those required under the IUCN year rule, are particularly sensitive to process errors, resulting in high levels of false positive and false negative species assessments Connors et al.
Concern has also been raised over the fundamental assumption that short-term declines are reliable predictors of ongoing decline and, therefore, extinction risk and authors have regularly advocated the use of long-term population data, where available, to improve the accuracy of extinction risk assessment Dunn ; Porszt et al.
These findings undermine confidence in the classification of extinction risk using Criterion A in its current form White However, these studies are based almost exclusively on vertebrate examples, where biological traits e. Indeed, Connors et al. These findings do not bode well for the application of Criterion A to insects. By comparison, the same rule applied to long-lived vertebrates would see trends measured over longer time periods equating to three generations of the species concerned.
In addition, the poikilothermic and ectothermic physiology of many insects results in climatic sensitivity that can drive large fluctuations in population size from generation to generation, particularly near altitudinal or latitudinal range margins Oliver et al.
Short-term climatic variation is a principal driver of inter-annual population change in UK butterflies and moths Roy et al. Due to anticipated high levels of process error as well as potential observation error , year population trends of insects may not be sufficiently reliable to enable the accurate classification of extinction risk in the Red List process, but rather reflect spurious responses to short-term environmental stochasticity.
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To save searches and access a historical view of information you have downloaded you are required to register for an account. Eastern Gorilla Critically Endangered, A4bcd ver 3.
Species categorized as Data Deficient DD. Species categorized as Least Concern LC. Species categorized as Near Threatened NT. Species categorized as Vulnerable VU. Species categorized as Endangered EN. Species categorized as Critically Endangered CR.
All reassessments on The IUCN Red List include a record of the reasons for any change in Red List Category, and this allows us to identify which species are genuinely improving or deteriorating in status.
Table 7 shows the list of species that have changed category, along with the reasons for these changes. In addition to species changing status, The IUCN Red List grows larger with each update as newly described species and species from the less well-known groups are assessed for the first time Figure 1.
IUCN and its partners are working to expand the number of taxonomic groups that have full and complete Red List assessments in order to improve our knowledge of the status of the world's biodiversity; see the Barometer of Life page for more information about this work.
Figure 1. Not all taxonomic groups have been completely assessed see Table 1 and Figure 2. It is very important to consider this when looking at the numbers of species in each Red List Category and the proportions of threatened species within each group; although The IUCN Red List gives a good snapshot of the current status of species, it should not be interpreted as a full and complete assessment of the world's biodiversity.
For many of the incompletely evaluated groups, assessment efforts have focused on those species that are likely to be threatened; therefore any percentage of threatened species reported for these groups would be heavily biased i. For those groups that have been comprehensively evaluated, the proportion of threatened species can be calculated, but the number of threatened species is often uncertain because it is not known whether DD species are actually threatened or not.
Some taxonomic groups are much better known that others i. Other, less well known groups have a large proportion of DD species, which brings uncertainty into the estimate for proportion of threatened species.
To account for the issues raised above, proportion of threatened species is only reported for the more completely evaluated groups i. Also, the reported percentage of threatened species for each group is presented as a best estimate within a range of possible values bounded by lower and upper estimates:. However, overall figures for numbers of species currently assessed in each Red List Category, along with an indication of which groups have been more comprehensively evaluated, can be found in the Summary Statistics Tables.
An overview of proportions of threatened species within each of the more comprehensively assessed groups is shown in Figure 2.
Note that this bar chart groups comprehensively assessed groups of species into classes, with the exception of reef-forming corals which is an ecosystem-based group that includes species from two separate classes: Anthozoa and Hydrozoa.
Only groups containing at least species are shown in Figure 2. Figure 2. The proportion of extant i. Version assessed in each category for the more comprehensively assessed i. Species are grouped into classes with the exception of reef-forming corals, which includes species from classes Hydrozoa and Anthozoa , and are ordered according to the vertical red lines, which indicate the best estimate for proportion of extant species considered threatened CR, EN, or VU.
Best estimates of percentage threatened species with lower and upper estimates for each group are: The numbers to the right of each bar represent the total number of extant species assessed for each group.
Tables 1 and 2 are organized by taxonomic group and show numbers of threatened species listed in the current version of The IUCN Red List in relation to the estimated number of described species Table 1a , and numbers of threatened species in each version of The IUCN Red List since Tables 1b and 2.
These tables highlight the disparity between the number of described species and the number of species that have been assessed. Table 1a - Number of species evaluated in relation to the overall number of described species, and numbers of threatened species by major groups of organisms.