Frontiers of Biogeography

Thankfully, the days when specimen localities could be described in extremely vague terms such as “Peru” or “Indochina” are long gone. But the pendulum has swung too far the other way. Latitude and longitude data of specimens and study areas (such as small nature reserves) are nowadays commonly reported to the 0.000001 of a degree (or 0.01 of a second) or even more “precisely”. This is done either because of converting across measurement systems or because hand-held devices and internet sources provide this kind of precision. We probably report this degree of precision because we are reluctant to round – feeling it would make the data better and more “scientific”. I point out the scale referred to by different degrees of geographic precision (e.g., ~10cm for 6 decimal places) and argue that such degree of precision is false for two reasons: first, it is finer than actually achievable by hand held devices such as smartphones and GPS receivers (and much finer than we can tell from a map). Second, for large animals, such precision can refer to one part of the organism, and not another. I urge scientists to use simple reality checks when reporting latitude and longitude data and report precision at meaningful scales.