A recent study that was published in Science shows that (for the most part) citizens are better at this task than their FWS counterparts. This was conducted by Berry Brosi of Emory University and Eric Biber of University of California, Berkeley School of Law. The pair built a database of more than 900 species listed as threatened or endangered and categorized them as FWS or citizen-initiated. Those cases were then charted against whether the suggestion interfered with a development project and the level of biological threat to the species, as well.
SOURCE LINK to full article: http://blog.ideascale.com/2012/09/11/crowdsourcing-the-endangered-species-list/