In Custodia Legis – “As the month of November ends, so does the annual fall migration season for birds in North America. According to the Cornell Lab of Ornithology, the adult breeding bird population in the United States and Canada has been reduced by almost 3 billion since 1970, a nearly 30% decline. Although the actual impact is difficult to measure, a 2005 study published by the U.S. Forest Service estimates that 500 million to 1 billion birds die annually from human-driven causes, with a significant number of those coming from collisions with buildings. The American Bird Conservancy  that up to one-third of bird species in the U.S. are affected by collisions. Even the most conservative estimates place the number of collisions in the hundreds of millions. The most significant contributor to bird collisions is glass. Many modern buildings use glass in their construction; however, it poses a problem for birds: depending on the time of day, glass can appear either transparent, reflective of the environment, or dark, mimicking an opening in the façade that is safe to fly through…” [h/t Pete Weiss]