To cite The IUCN Red List of Threatened Species in general or to cite specific assessments, users are advised to follow the formats suggested below, changing the dates and version numbers as appropriate.
In text, for The IUCN Red List in general, use "...IUCN (2014)..." or "...(IUCN 2014)...". To cite specific assesments in the text use the authors of the assessment and the date the assessment was published (for these details, see the suggested citation at the bottom of the relevant species fact sheet). So for example in referring to the assessment of Zaglossus bruijnii (seehttp://www.iucnredlist.org/details/23179/0) this would be cited as "....Leary et al. (2008)..." or "...(Leary et al. 2008)...."
In the bibliography or works cited section, the above would be cited in full as follows:
For The IUCN Red List in general -
IUCN 2014. The IUCN Red List of Threatened Species. Version 2014.2. <http://www.iucnredlist.org>. Downloaded on 24 July 2014.
To cite a specific assessment, please use the citation that appears at the bottom of the species fact sheet. This generally uses the Assessor(s) name(s), the date the assessment was published, and the taxon name followed by part of The IUCN Red List citation. For example:
Leary, T., Seri. L., Flannery, T., Wright, D., Hamilton, S., Helgen, K., Singadan, R., Menzies, J., Allison, A., James, R., Aplin, K., Salas, L. and Dickman, C. 2008. Zaglossus bruijnii. The IUCN Red List of Threatened Species. Version 2014.2. <http://www.iucnredlist.org/>. Downloaded on 24 July 2014.
Lafrance, P., Lourie, S., Marsden, D. and Vincent, A.C.J. 2002.Hippocampus subelongatus. The IUCN Red List of Threatened Species. Version 2014.2. <http://www.iucnredlist.org/>. Downloaded on 24 July 2014.