Recently, this came up during the lunch discussion with my colleagues at Broadcom. I remember reading up an article somewhere, quoting the impact of birds migration due to cellular phone towers.
Researchers from Research Institute for Nature and Forest, Brussels, Belgium have investigated into this subject and published an article (more reports here). According to the authors (Joris Everaert and Dirk Bauwens),the house sparrows do not prefer to stay near the GSM base stations because the radiation in the 900 MHz range is adversely affecting them. The paper investigated the male house sparrow population. The statistics quoted in this paper clearly shows that, there is some kind of an impact the cellular tower radiation is causing onto the city birds.Perhaps a more scientific study on this is needed to assess the details, but this itself is a reason to worry.
Another interesting blog comes from India, which also suggests that the Belgian research finding is correlated to what is observed elsewhere. But then, I am wondering how come there were thousands of sparrows flooded across almost every street at Schaffhausen. We had been on a family holiday there, last year. It was the place where I have seen the highest amount of sparrows, all waiting to get fed and pampered! May be they have adapted to the technology, huh?