I've been exploring the concept that our perception of the natural world, being based on our own life's experience, is being measured against a false baseline. That is, what we consider a normal or even diminished number of birds under our feeder is based on the amount of birds we saw as a child or whenever we first put up that feeder. This change in the number of birds being judged against our own personal baseline (childhood memory) does not reflect the actual change in bird species over hundreds of years. We can be lured into a false sense of normalcy when in fact we are watching a great decline. One fascinating study was conducted by Loren McClenachan who used photos from fishing tours in Key West, FL to make visual this trend. The look of satisfaction on the faces of the fishermen remains static, the size of the catch does not. The study was examined by NPR and summarized nicely by Robert Krulwich.