I am wondering if their is a site or database that allows you to look up the endangered species/ or animals/species population data. I am wondering how the national parks ... like yellow stone ,...etc know when a certain animal is endangered or how they collect/ know for sure they are accurate. For example Panda Bears are one animal that is on the endangered species list. I am curious how they know this for sure and if their is a way to measure/get the population data of certain animals in certain regions. Any environmentalist out their that can shed some light on this. I am very interested in how one can gather data accurately on animals? For people we can easily use surveys and tax forms to get a rough estimate on human population. (at least humans are a little easier to keep track of normally) But when it comes to animals seems to me it would be nearly impossible.... and nearly impossible to know if an animal is on the in dangered species list or not.... or weather it is going to be.