Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Philos Trans R Soc Lond B Biol Sci ; 366(1578): 2598-610, 2011 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-21844039

RESUMO

A recent complete assessment of the conservation status of 5487 mammal species demonstrated that at least one-fifth are at risk of extinction in the wild. We retrospectively identified genuine changes in extinction risk for mammals between 1996 and 2008 to calculate changes in the International Union for Conservation of Nature (IUCN) Red List Index (RLI). Species-level trends in the conservation status of mammalian diversity reveal that extinction risk in large-bodied species is increasing, and that the rate of deterioration has been most accelerated in the Indomalayan and Australasian realms. Expanding agriculture and hunting have been the main drivers of increased extinction risk in mammals. Site-based protection and management, legislation, and captive-breeding and reintroduction programmes have led to improvements in 24 species. We contextualize these changes, and explain why both deteriorations and improvements may be under-reported. Although this study highlights where conservation actions are leading to improvements, it fails to account for instances where conservation has prevented further deteriorations in the status of the world's mammals. The continued utility of the RLI is dependent on sustained investment to ensure repeated assessments of mammals over time and to facilitate future calculations of the RLI and measurement against global targets.


Assuntos
Conservação dos Recursos Naturais/métodos , Ecossistema , Espécies em Perigo de Extinção , Extinção Biológica , Mamíferos/crescimento & desenvolvimento , Animais , Estudos Retrospectivos
2.
Science ; 330(6010): 1503-9, 2010 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-20978281

RESUMO

Using data for 25,780 species categorized on the International Union for Conservation of Nature Red List, we present an assessment of the status of the world's vertebrates. One-fifth of species are classified as Threatened, and we show that this figure is increasing: On average, 52 species of mammals, birds, and amphibians move one category closer to extinction each year. However, this overall pattern conceals the impact of conservation successes, and we show that the rate of deterioration would have been at least one-fifth again as much in the absence of these. Nonetheless, current conservation efforts remain insufficient to offset the main drivers of biodiversity loss in these groups: agricultural expansion, logging, overexploitation, and invasive alien species.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais , Ecossistema , Vertebrados , Anfíbios , Animais , Aves , Espécies em Perigo de Extinção/estatística & dados numéricos , Espécies em Perigo de Extinção/tendências , Extinção Biológica , Espécies Introduzidas , Mamíferos , Dinâmica Populacional
3.
Science ; 322(5899): 225-30, 2008 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-18845749

RESUMO

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.


Assuntos
Biodiversidade , Extinção Biológica , Mamíferos , Animais , Tamanho Corporal , Conservação dos Recursos Naturais , Bases de Dados Factuais , Ecossistema , Mamíferos/anatomia & histologia , Mamíferos/classificação , Mamíferos/fisiologia , Biologia Marinha , Filogenia , Dinâmica Populacional , Água do Mar
4.
Sci China C Life Sci ; 50(2): 265-76, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17447035

RESUMO

The conservation status of all the amphibians in China is analyzed, and the country is shown to be a global priority for conservation in comparison to many other countries of the world. Three Chinese regions are particularly rich in amphibian diversity: Hengduan, Nanling, and Wuyi mountains. Salamanders are more threatened than frogs and toads. Several smaller families show a high propensity to become seriously threatened: Bombinatoridae, Cryptobranchidae, Hynobiidae and Salamandridae. Like other parts of the world, stream-breeding, high-elevation forest amphibians have a much higher likelihood of being seriously threatened. Habitat loss, pollution, and over-harvesting are the most serious threats to Chinese amphibians. Over-harvesting is a less pervasive threat than habitat loss, but it is more likely to drive a species into rapid decline. Five conservation challenges are mentioned with recommendations for the highest priority research and conservation actions.


Assuntos
Anfíbios , Conservação dos Recursos Naturais/tendências , Anfíbios/classificação , Animais , Biodiversidade , China , Geografia , Ranidae/classificação , Urodelos/classificação
5.
Science ; 306(5702): 1783-6, 2004 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-15486254

RESUMO

The first global assessment of amphibians provides new context for the well-publicized phenomenon of amphibian declines. Amphibians are more threatened and are declining more rapidly than either birds or mammals. Although many declines are due to habitat loss and overutilization, other, unidentified processes threaten 48% of rapidly declining species and are driving species most quickly to extinction. Declines are nonrandom in terms of species' ecological preferences, geographic ranges, and taxonomic associations and are most prevalent among Neotropical montane, stream-associated species. The lack of conservation remedies for these poorly understood declines means that hundreds of amphibian species now face extinction.


Assuntos
Anfíbios , Biodiversidade , Ecossistema , Anfíbios/classificação , Animais , Conservação dos Recursos Naturais , Meio Ambiente , Dinâmica Populacional
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...