科研之友
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摘要
Several classification systems are used to rank species' extinction risk. Assessments from two of these, IUCN and NatureServe, are often used to inform prioritisation of conservation resources and management strategies. However, despite their widespread use, they have rarely been compared. No research has assessed rank concordance specifically for mammals, while factors increasing the chance of mismatches between systems have not been investigated. In this study, consistency of IUCN/NatureServe extinction risk categorisation is compared for 409 classified extant American and Canadian mammals. Taxonomic bias in between-system mismatches is then analysed, and common ecological factors associated with mismatches are also identified. There was a significant positive correlation between IUCN and NatureServe ranks, although this was not strong (r(s) = 0.504). Agreement was good for non-threatened categories: 97% of species classified as non-threatened by one system were classified likewise by the other. However, there was considerable discord in threatened categories, with 40% of species classified as threatened by one system and non-threatened by the other. In 89% of such cases, this was due to higher ranking by NatureServe, suggesting that this system is more conservative. Mismatches were identified for 102 of the 373 species with exact rankings on both systems (27%), and these were biased taxonomically with significantly more mismatches for Cetacea and fewer for Rodentia. Mismatches were more common for species with longer gestation periods, fewer offspring per year, and longer life expectancies (all traits associated with K-strategist species), as well as for species in higher trophic levels. Many mismatched species also had fragmented ranges and/or uncertain data. Recognition that IUCN and NatureServe ranks are not synonymous is essential. Assessments should be viewed as complementary and dual results should be used to inform species management. The need for more detailed population demographic data to improve extinction risk calculations should also be addressed.
- 出版日期2012-3
