Yes, I am not convinced either, but as Latetonite says "it can't hurt, and even if the birds couldn't care less, it might help someone avoid the CB cloud a little further on. David Attenborough regales us with tales of new scientific and ornithological discoveries that are made every year, as to the previously unknown sensory capabilities of these creatures, so who knows? I am happy to wear odd socks if it is perceived to improve the odds.