SAD (not seasonal affective disorder)

[ebrownrma]

One thing I've run into working in a tropical biodiversity hotspot is that some species that are traditionally thought to be rare only appear to be due to sampling bias. Whether it's because a species is nocturnal, has great aversion to any human disturbance (including scent), etc., there are few, if any, data sets that can be said to honestly represent their presence/densities on the landscape (e.g. pen-tailed treeshrews in Borneo; once thought to be scarce, but demonstrated to be quite populous at night). Especially for species whose life histories largely remain unknown, how can we be sure that a SAD honestly predicts their presence in a community?