Mattila et al. propose that many species at risk of extinction may be linked by similar ecological traits. In their discussion, for example, they cite studies that species with high diet or habitat specificity are at greater risk of extinction (surprise!), and that’s true across taxa. Their study looks at moths in Finland and compares their ecological traits with IUCN red list status (clumped into threatened and non-threatened). Of course, this is really comparing ecological traits with the probability of being listed as threatened/endangered under IUCN standards. I’m curious to know if there is something else that pushes a species over the edge from critically endangered to extinct. That is, some species can be quite successful at low densities; others might be endangered due to habitat loss, but at high densities within the remaining habitat. What are the patterns that actually cause extinction, as opposed to the threat of extinction?

Matilla, N., et al. The use of ecological traits in exctinction risk assessments: A case study on gemetrid moths. Biological Conservation, in press. doi:10.1016/j.biocon.2008.06.024.