21 research outputs found

    How many bird and mammal extinctions has recent conservation action prevented?

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    Aichi Target 12 of the Convention on Biological Diversity (CBD) aims to ‘prevent extinctions of known threatened species’. To measure its success, we used a Delphi expert elicitation method to estimate the number of bird and mammal species whose extinctions were prevented by conservation action in 1993 - 2020 (the lifetime of the CBD) and 2010 - 2020 (the timing of Aichi Target 12). We found that conservation prevented 21–32 bird and 7–16 mammal extinctions since 1993, and 9–18 bird and 2–7 mammal extinctions since 2010. Many remain highly threatened, and may still become extinct in the near future. Nonetheless, given that ten bird and five mammal species did go extinct (or are strongly suspected to) since 1993, extinction rates would have been 2.9–4.2 times greater without conservation action. While policy commitments have fostered significant conservation achievements, future biodiversity action needs to be scaled up to avert additional extinctions

    Protecting Important Sites for Biodiversity Contributes to Meeting Global Conservation Targets

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    Protected areas (PAs) are a cornerstone of conservation efforts and now cover nearly 13% of the world's land surface, with the world's governments committed to expand this to 17%. However, as biodiversity continues to decline, the effectiveness of PAs in reducing the extinction risk of species remains largely untested. We analyzed PA coverage and trends in species' extinction risk at globally significant sites for conserving birds (10,993 Important Bird Areas, IBAs) and highly threatened vertebrates and conifers (588 Alliance for Zero Extinction sites, AZEs) (referred to collectively hereafter as ‘important sites’). Species occurring in important sites with greater PA coverage experienced smaller increases in extinction risk over recent decades: the increase was half as large for bird species with>50% of the IBAs at which they occur completely covered by PAs, and a third lower for birds, mammals and amphibians restricted to protected AZEs (compared with unprotected or partially protected sites). Globally, half of the important sites for biodiversity conservation remain unprotected (49% of IBAs, 51% of AZEs). While PA coverage of important sites has increased over time, the proportion of PA area covering important sites, as opposed to less important land, has declined (by 0.45–1.14% annually since 1950 for IBAs and 0.79–1.49% annually for AZEs). Thus, while appropriately located PAs may slow the rate at which species are driven towards extinction, recent PA network expansion has under-represented important sites. We conclude that better targeted expansion of PA networks would help to improve biodiversity trends

    The status of the world's land and marine mammals: diversity, threat, and knowledge

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    Knowledge of mammalian diversity is still surprisingly disparate, both regionally and taxonomically. Here, we present a comprehensive assessment of the conservation status and distribution of the world's mammals. Data, compiled by 1700+ experts, cover all 5487 species, including marine mammals. Global macroecological patterns are very different for land and marine species but suggest common mechanisms driving diversity and endemism across systems. Compared with land species, threat levels are higher among marine mammals, driven by different processes (accidental mortality and pollution, rather than habitat loss), and are spatially distinct (peaking in northern oceans, rather than in Southeast Asia). Marine mammals are also disproportionately poorly known. These data are made freely available to support further scientific developments and conservation action

    Synergies between the key biodiversity area and systematic conservation planning approaches

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    Systematic conservation planning and Key Biodiversity Areas (KBAs) are the two most widely used approaches for identifying important sites for biodiversity. However, there is limited advice for conservation policy makers and practitioners on when and how they should be combined. Here we provide such guidance, using insights from the recently developed Global Standard for the Identification of KBAs and the language of decision science to review and clarify their similarities and differences. We argue the two approaches are broadly similar, with both setting transparent environmental objectives and specifying actions. There is however greater contrast in the data used and actions involved, as the KBA approach uses biodiversity data alone and identifies sites for monitoring and vigilance actions at a minimum, whereas systematic conservation planning combines biodiversity and implementation‐relevant data to guide management actions. This difference means there is much scope for combining approaches, so conservation planners should use KBA data in their analyses, setting context‐specific targets for each KBA type, and planners and donors should use systematic conservation planning techniques when prioritizing between KBAs for management action. In doing so, they will benefit conservation policy, practice and research by building on the collaborations formed through the KBA Standard's development

    How many bird and mammal extinctions has recent conservation action prevented?

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    Aichi Target 12 of the Convention on Biological Diversity (CBD) contains the aim to ‘prevent extinctions of known threatened species’. To measure the degree to which this was achieved, we used expert elicitation to estimate the number of bird and mammal species whose extinctions were prevented by conservation action in 1993–2020 (the lifetime of the CBD) and 2010–2020 (the timing of Aichi Target 12). We found that conservation action prevented 21–32 bird and 7–16 mammal extinctions since 1993, and 9–18 bird and two to seven mammal extinctions since 2010. Many remain highly threatened and may still become extinct. Considering that 10 bird and five mammal species did go extinct (or are strongly suspected to) since 1993, extinction rates would have been 2.9–4.2 times greater without conservation action. While policy commitments have fostered significant conservation achievements, future biodiversity action needs to be scaled up to avert additional extinctions.https://wileyonlinelibrary.com/journal/conlMammal Research Institut

    Investigating orphan cytochromes P450 from Mycobacterium tuberculosis : the search for potential drug targets

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    Tuberculosis (TB) is a disease that the World Health Organisation (WHO) regards as a global pandemic. There is a great need for new drugs to combat this threat. Drug resistant strains of the causative agent, Mycobacterium tuberculosis (Mtb), have increased the urgency of this quest for novel anti-mycobacterial medicines. Publication of the Mtb genome sequence revealed a large number of cytochrome P450 (CYP) enzymes [Cole, S. T. et al. 1998]. These mono-oxygenase enzymes have been studied for many years and are responsible for metabolic functions in every kingdom of life. Research on the Mtb P450s to date has highlighted several of them as having critcal roles within the organism. CYP121 and CYP128 have been implicated as essential through gene knockout studies. It has been demonstrated that CYP125 is not essential for viability. However, it is part of a gene cluster highly important for Mtb infectivity and virulence. Due to the prospective importance of P450s to Mtb, this group of enzymes is under investigation as a source of novel drug targets. CYP142 was discovered as a potential drug target after it was located to a gene cluster involved in cholesterol catabolism during Mtb dormancy. As part of this PhD project, it was demonstrated that CYP142 performs an almost identical role to that reported for CYP125. These enzymes both perform C27 hydroxylation and carboxylation of the cholesterol side chain. However, variations in the level of oxidation have been identified, dependent upon the redox system with which these P450s are associated. A crystal structure of CYP142 showing high similarity in active site architecture to CYP125 supports the physiological role of CYP142 in cholesterol catabolism. Combining this with in vitro data which demonstrates that CYP142 possesses high affinity for a range of azole anti-fungal agents [Ahmad, Z. et al. 2005, 2006] supports the suggestion that it is a candidate target for the next generation of anti-mycobacterial drugs. CYP144 was highlighted as being important during the latent phase of Mtb growth, a phase that is not targeted by any of the current antimycobacterials. Work performed as part of this PhD has shown that many characteristics of CYP144 are highly comparable to those reported for other MtbP450s. CYP144 shows high affinity and specificity towards many azole molecules. Econazole, clotrimazole and miconazole have repeatedly been shown to bind to MtbP450s, including CYP144 and CYP142, with high affinity and are excellent potential candidates as novel anti-mycobacterial agents. An N-terminally truncated form of CYP144, CYP144-T, has been investigated in the pursuit of a CYP144 crystal structure. It is hoped that this will enable the elucidation of a physiological role for CYP144. Both CYP142 and CYP144 have demonstrated biochemical and biophysical characteristics that contribute to our knowledge of P450 enzymes. This PhD has established that CYP142 exhibits an equilibrium between P450 and P420 species in its CO-bound, ferrous form. A conversion from P420, and stabilisation of P450, upon substrate binding was also demonstrated. CYP144 displays unusual azole coordination characteristics when examined by EPR and removal of the CYP144 gene from Mtb increased sensitivity of the strain to clotrimazole. Studies of these enzymes has advanced knowledge of P450 and Mtb redox chemistry, established roles for the MtbP450 cohort and identified the potential of anti-mycobacterial drugs and associated targets.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    ASSOCIATION OF ANDROGENETIC ALOPECIA WITH SMOKING AND ITS PREVALENCE AMONG ASIAN MEN - A COMMUNITY-BASED SURVEY

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    Beta-diversity, the change in species composition between places, is a critical but poorly understood component of biological diversity. Patterns of beta-diversity provide information central to many ecological and evolutionary questions, as well as to conservation planning. Yet beta-diversity is rarely studied across large extents, and the degree of similarity of patterns among taxa at such scales remains untested. To our knowledge, this is the first broad-scale analysis of cross-taxon congruence in beta-diversity, and introduces a new method to map beta-diversity continuously across regions. Congruence between amphibian, bird, and mammal beta-diversity in the Western Hemisphere varies with both geographic location and spatial extent. We demonstrate that areas of high beta-diversity for the three taxa largely coincide, but areas of low beta-diversity exhibit little overlap. These findings suggest that similar processes lead to high levels of differentiation in amphibian, bird, and mammal assemblages, while the ecological and biogeographic factors influencing homogeneity in vertebrate assemblages vary. Knowledge of beta-diversity congruence can help formulate hypotheses about the mechanisms governing regional diversity patterns and should inform conservation, especially as threat from global climate change increases

    Analysis of ocular hypopigmentation in Rab38cht/cht mice.

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    PURPOSE: To characterize the ocular phenotype resulting from mutation of Rab38, a candidate gene for Hermansky-Pudlak syndrome. METHODS: Chocolate mice (cht, Rab38(cht/cht)) and control heterozygous (Rab38(cht/)(+)) and wild-type mice were examined clinically, histologically, ultrastructurally, and electrophysiologically. Mice homozygous for both the Rab38(cht) and the Tyrp1(b) alleles were similarly examined. RESULTS: Rab38(cht/cht) mice showed variable peripheral iris transillumination defects at 2 months of age. Patches of RPE hypopigmentation were noted clinically in 57% of Rab38(cht/cht) eyes and 6% of Rab38(cht/)(+) eyes. Rab38(cht/cht) mice exhibited thinning of the iris and RPE and larger b-wave amplitudes in the scotopic range when compared with the control animals. Compared with wild-type mice, Rab38(cht/cht) melanosomes were smaller and there were fewer in neuroectodermally derived retinal pigment epithelium; in neural crest-derived choroid melanocytes, they were smaller in size only. Mutation of both Rab38 and Tyrp1 produced mice with ocular and coat color pigment dilution greater than that seen with either mutation alone. Comprehensive clinical and pathologic analyses showed no other organ system or blood defects in Rab38(cht/cht) mice. CONCLUSIONS: Rab38(cht/cht) mice show ocular characteristics reminiscent of human oculocutaneous albinism, as well as iris and RPE thinning. The synergistic effects of the Rab38(cht) and Tyrp1(b) alleles suggest that TYRP1 is not the only target of RAB38 trafficking. This mouse line provides a useful model for studying melanosome biology and its role in human ocular diseases

    Plenary PaperObjectifs et priorités pour la conservation des oiseaux et de la biodiversité d'Afrique

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    RĂ©sumĂ©: La biodiversitĂ© est confrontĂ©e Ă  une grave crise d'extinction avec des pertes d'espĂšces qui atteignent des niveaux trois fois plus importants que les moyennes estimĂ©es sur les temps gĂ©ologiques. Cependant, ni la biodiversitĂ©, ni les menaces ne sont distribuĂ©es de maniĂšre alĂ©atoire sur la planĂšte et il est donc extrĂȘmement important de bien dĂ©finir les objectifs et les prioritĂ©s pour entreprendre des actions de conservation destinĂ©es Ă  prĂ©server au mieux la biodiversitĂ©. De façon plus gĂ©nĂ©rale, les prioritĂ©s peuvent ĂȘtre Ă©tablies en considĂ©rant les caractĂšres de vulnĂ©rabilitĂ© et irremplaçabilitĂ© Ă  partir desquels les ‘hotspots' (ou centres nĂ©vralgiques) de la biodiversitĂ© et les ‘rĂ©gions naturelles Ă  biodiversitĂ© Ă©levĂ©e' ont Ă©tĂ© dĂ©limitĂ©s. Une nouvelle estimation rĂ©cente de ces aspects a reconnu 34 ‘hotspots' et cinq ‘rĂ©gions naturelles Ă  forte biodiversitĂ©' dans le monde dont, neuf et deux sont respectivement distribuĂ©s en Afrique. Nous procĂ©dons ici Ă  une estimation des prioritĂ©s de conservation pour les oiseaux et nous montrons qu'elles sont Ă©levĂ©es. Cependant, ces estimations gĂ©nĂ©rales ne servent pas la conservation sur le terrain. Pour Ă©tablir les objectifs de la conservation, il nous faut un systĂšme acceptĂ© et gĂ©rĂ© le plus prĂšs possible du terrain mais conformĂ©ment aux standards internationaux, afin d'estimer la biodiversitĂ© Ă  de multiples Ă©chelles de l'organisation Ă©cologique. Le meilleur niveau auquel nous disposons gĂ©nĂ©ralement de donnĂ©es complĂštes est situĂ©e au rang de l'espĂšce oĂč nous pouvons appliquer la Liste Rouge de l'UICN pour dĂ©terminer les objectifs de la conservation. Nous vĂ©rifions dans quelle mesure les niveaux de menace qui pĂšsent sur les oiseaux reflĂštent ceux auxquels sont soumis d'autres taxons et montrons que les oiseaux reprĂ©sentent l'un des groupes taxinomiques les moins menacĂ©s. La plupart des espĂšces menacĂ©es, et cela quelque soit le groupe taxinomique retenu, sont mieux conservĂ©es Ă  travers un rĂ©seau de parcs et de rĂ©serves protĂ©gĂ©s et nous pouvons donc prendre en considĂ©ration les donnĂ©es relatives Ă  leur distribution pour identifier les «Zones d'Importance pour la Biodiversité» (ZIB) qui seront les objectifs de la conservation au niveau du site. Il s'agit d'un dĂ©rivĂ© du concept des «Zones d'Importance pour la Conservation des Oiseaux» (ZICO) qui a dĂ©jĂ  Ă©tĂ© retenu sur l'ensemble du continent africain. À partir des donnĂ©es provenant d'Afrique de l'Est et de Madagascar, la plupart des espĂšces des groupes non aviens semblent ĂȘtre reprĂ©sentĂ©es dans les ZICO mĂȘme si de nombreux autres sites peuvent Ă©galement ĂȘtre identifiĂ©s pour d'autres taxons. Alors que la protection des sites est primordiale pour la conservation de la biodiversitĂ©, elle ne sera satisfaisante qu'Ă  condition que les processus Ă©cologiques permettant le maintien de ces sites avec ses espĂšces soient maintenus, jusqu'Ă  envisager des interventions sur l'environnement en considĂ©rant des ‘corridors' de conservation de la biodiversitĂ©, si nĂ©cessaires. Les ornithologues africains peuvent participer au processus d'identification des objectifs de la conservation en incitant leurs collĂšgues dans autres disciples de la zoologie et de la botanique Ă  compiler des donnĂ©es obtenues selon des mĂ©thodologies comparables ou encore en participant directement aux Ă©tudes portant sur d'autres groupes taxinomiques mais surtout et avant tout en maintenant la qualitĂ© et le niveau des donnĂ©es ornithologiques pour le continent. Abstract: Biodiversity is facing an extinction crisis, with rates of species loss three orders of magnitude higher than average throughout geological history. However, neither biodiversity nor threats are randomly distributed around the planet, and so it is extremely important to target and prioritize conservation activities to make them as effective as possible in preserving biodiversity. At a global scale, priorities can be set by considering a framework of irreplaceability and vulnerability, from which biodiversity ‘hotspots' and ‘high-biodiversity wilderness areas' can be derived. Recent re-evaluation of these reveals that nine of the world's 34 hotspots and two of five high biodiversity wilderness areas lie in Africa. We assess the extent to which these conservation priorities are also priorities for bird conservation, and show that it is high. However, these global assessments do not inform conservation on the ground. For establishment of conservation targets, we require a system, driven and owned as close to the ground as possible, but following global standards, which assesses biodiversity at multiple scales of ecological organization. The finest scale at which comprehensive data are generally available is the level of the species, where we can use the IUCN Red List to determine targets for conservation. We ask how well levels of threat in birds reflect those in other taxa, and show that birds are one of the least threatened taxonomic groups. Regardless of taxon, most threatened species are best conserved through protecting areas, and so we can use information regarding their distributions to identify Key Biodiversity Areas (KBAs) as targets for site scale conservation. This builds from the concept of Important Bird Areas (IBAs), already applied across Africa. Based on data from East Africa and Madagascar, most species in non-bird groups appear to be represented in IBAs, although numerous additional sites can also be identified for other taxa. While the protection of sites is essential for biodiversity conservation, it will not be sufficient unless we maintain the ecological processes that allow these sites and species to persist, for which landscape interventions through biodiversity conservation ‘corridors' are necessary. African ornithologists can contribute to the process of identifying conservation targets by inspiring colleagues from other zoological and botanical disciplines to compile data in similarly comprehensive ways, by contributing directly to studies of other taxa, and above all by maintaining the flow of high quality ornithological data for the continent. Ostrich 2007, 78(2): 115–12
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